2004 anesth practice ques ebook
DESCRIPTION
anes practiceTRANSCRIPT
AnesthesiaAnesthesia Practice QuestionsPractice Questions
Book 1Book 1
Edited by Rodolfo Amaya, MD
Gregory A. Smith, MD Medt
ext M
edic
al W
orld
, Inc.
Medt
ext M
edic
al W
orld
, Inc.
Copyright 2004 Medtext Medical World, Inc.
www.medtext.net [email protected]
c/o Editorial Office 700 N. Pacific Coast Highway
Suite #302 Redondo Beach, CA 90277
1-888-MEDTEXT (633-8398)
All rights reserved. This book is protected by copyright. No part of this book may be reproduced in any form or by any means, including photocopying, or utilized by any information storage and retrieval system without written permission from the copyright owner, see above address. Printed in the United States of America. ISBN 1-889344-65-6 Please Note: Our knowledge in the clinical sciences changes on a constant basis. Much care has been taken to make certain that the information contained within this book is correct and accurate. However, the reader is advised to consult all relevant educational and instructional literature regarding questionable data. ANESTHESIA PRACTICE QUESTIONS BOOK 1 - 2004
Anesthesia Practice Questions Book 1 – 2004
Edited by Rodolfo Amaya, MD
Gregory A. Smith, MD
Contributors
EDITOR
Rodolfo Amaya, MD Assistant Professor and Clinical Coordinator
Department of Anesthesiology Keck School of Medicine of USC
Los Angeles, California
Gregory A. Smith, MD Private Practice
Comprehensive Pain Relief Group Redondo Beach, CA
CONTRIBUTORS
Rodolfo Amaya, MD Assistant Professor and Clinical Coordinator
Department of Anesthesiology Keck School of Medicine of USC
Los Angeles, California
J. Sudharma Ranasinghe, MD, FFARCSI Assistant Professor of Anesthesiology University of Miami School of Medicine
Jackson Memorial Medical Center Miami, Florida
M. Iqbal Shaikh, MD, PhD Department of Anesthesia and Peri-operative Care
University of California, San Francisco School of Medicine San Francisco, California
Acknowledgments As editor of this publication, I could not do it alone and I have to thank the contributions of my fellow authors. With their help, Medtext has provided what I believe is a very comprehensive review for the written boards. I wish every reader the best of luck. Also, I would like to thank Medtext Publishing for providing this opportunity for board review. My studies for the written boards (back when) would not have been complete had there not been these review publications. Keep up the good work! Rodolfo Amaya, MD
Dedication
To my wife Laleh, thank you for your encouragement, patience and understanding. I’m sorry for bringing my work home.
I love you.
Questions
Anesthesia Book 1 – 2004 ANSWER SHEET
There are 250 blocks below to record your answers. 1
26 51 76 101 126 151 176 201 226
2
27 52 77 102 127 152 177 202 227
3
28 53 78 103 128 153 178 203 228
4
29 54 79 104 129 154 179 204 229
5
30 55 80 105 130 155 180 205 230
6
31 56 81 106 131 156 181 206 231
7
32 57 82 107 132 157 182 207 232
8
33 58 83 108 133 158 183 208 233
9
34 59 84 109 134 159 184 209 234
10
35 60 85 110 135 160 185 210 235
11
36 61 86 111 136 161 186 211 236
12
37 62 87 112 137 162 187 212 237
13
38 63 88 113 138 163 188 213 238
14
39 64 89 114 139 164 189 214 239
15
40 65 90 115 140 165 190 215 240
16
41 66 91 116 141 166 191 216 241
17
42 67 92 117 142 167 192 217 242
18
43 68 93 118 143 168 193 218 243
19
44 69 94 119 144 169 194 219 244
20
45 70 95 120 145 170 195 220 245
21
46 71 96 121 146 171 196 221 246
22
47 72 97 122 147 172 197 222 247
23
48 73 98 123 148 173 198 223 248
24
49 74 99 124 149 174 199 224 249
25
50 75 100 125 150 175 200 225 250
Please remove from the book before beginning.
When you open your eBook you will see the screen split into two sections - the left section is the navigation area, the right section contains the content of your eBook.
Once you've opened your eBook and are ready to start reading you have several options to assist you in moving from page to page. Medtext has provided a clickable navigation area that will allow you to jump from question to answer, or from section to section. Each section is titled in bold text - Book Title, Questions Section, Answers Section, etc. You can click on any item listed in the Navigation.
You will see a + or - (plus or minus) next to each section. If a + (plus) is visible, click the plus to expand the list of navigational links for that section. If a - (minus) is visible, you can collapse the list by clicking on the - (minus). See the images above for details. Using these links, you can move from Question 1 to Answer 1; return to Question 2 to Answer 2, etc. If you prefer to move through the book page by page, locate the page number navigation bar at the bottom of your screen and click the arrows to move forward or back.
You can adjust the size of the text you are reading by using the "Zoom In" and "Zoom Out" buttons on the toolbar at the top of your screen in Adobe Reader. Roll your curser over each button to view the button title.
Clicking on the Magnifying Glass (with the plus sign in the middle) will attach the magnifying glass to your curser and allow you to click on a specific location on the page to enlarge. You can right click while the Magnifying Glass is still attached to your curser to select a magnification level from the list. Clicking on "Actual Size" will change your view to the actual size of the printed page. Clicking on "Fit Page" - will change your view so that the entire page fits on your monitor screen. Clicking on "Fit Width" will change your view so that the width of your monitor is fully utilized. The - (minus), percentage number and + (plus) show you what percentage you are currently viewing. You can click - (minus) to make the text (page) smaller, or + (plus) to make the text (page) larger. For further assistance using Acrobat Reader software, The Acrobat Reader 6.0 User's Guide is included on this CD.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
15
1. A 35-year-old woman in active labor had an epidural catheter placed and was given a bolus of 10 ml of 0.5% bupivacaine containing 1:200,000 epinephrine. Twenty minutes later maternal blood pressure drops to 75/45 mmHg and heart rate to 69 bpm. The Ob/Gyn nurse informs you that the fetal heart is 90 bpm and there is a loss of beat-to-beat variability. The MOST likely explanation for fetal bradycardia and loss of beat-to-beat variability is:
A) Fetal bupivacaine toxicity B) Maternal supine hypotension syndrome C) Maternal bupivacaine toxicity D) Maternal increased sensitivity to local anesthetics E) Umbilical cord compression
2. Following successful placement of an epidural, a 25-year-old woman had an
uncomplicated labor and delivery. However during catheter removal, the catheter breaks 1 cm from the tip.
What would be the MOST appropriate action?
A) Inform the patient and take no action B) Start the patient on prophylactic antibiotics C) Call the surgical consult and request surgical exploration D) Request an additional study of the epidural space using contrast dye E) Conceal the whole information and tell the patient everything went smoothly
3. Epidural test dose contains 5 microgram per ml of epinephrine. Suppose you
administer a test dose of lidocaine containing 15 micrograms of epinephrine. This would be sufficient to produce:
A) Bradycardia B) Hypertension C) Seizure D) Segmental analgesia E) Cardiovascular collapse
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
16
4. Which of the following regional blocks are associated with the HIGHEST serum concentration of local anesthetics? Assume you use an identical dose.
A) Thoracic epidural B) Caudal C) Brachial plexus D) Intercostal E) Epidural
5. Epidural opioids combined with local anesthetics are increasingly used for optimal
management of intraoperative and post-operative analgesia.
Which of the following statements regarding this combination are TRUE?
A) Fentanyl when combined with epidural bupivacaine will decrease the concentration of the later for satisfactory analgesia
B) Fentanyl if used alone can be as effective as local anesthetics for the second stage of labor
C) Sufentanil is not appropriate for labor analgesia because it produces unsatisfactory analgesia
D) The addition of epinephrine to fentanyl will prolong the duration of analgesia E) The main determinant of the onset of epidural opioid analgesia is water
solubility 6. Which of the following properties of bupivacaine BEST explains its cardiac toxicity
when compared to other local anesthetics?
A) Bupivacaine is more soluble in water B) Bupivacaine produces a sustained block of open calcium channels C) Bupivacaine enhances sodium-potassium exchange in the myocardium D) Bupivacaine increases the sensitivity of myocardial myocardium E) Bupivacaine blocks cardiac sodium channels for prolonged period
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
17
7. A 60-year-old male scheduled for second and third digits tendon repair of the left hand, had a brachial plexus block placed using trans-arterial approach. Fifteen minutes later he is still complaining of sensation and pain with pin prick on the dorsum of the second and third digits.
What will be the MOST appropriate approach to completely block the unaffected site?
A) Inject 3 ml of local anesthetics lateral to biceps tendon at the flexion of the crease
B) Inject 2 ml of local anesthetics 2 cm lateral to the radial border of palmaris longus tendon
C) Inject 5 ml of local anesthetics between medial epicondyle and olecranon process proximal to arcuate ligament
D) Inject 2 ml of local anesthetics between the interval of the radial artery and flexor carpi radialis tendon
E) Re-perform the axillary block using another 10 ml of LA
8. A 60-year-old man had an interscalene block for a closed reduction of his left
humerus. Fifteen (15) minutes later he has difficulty speaking. The MOST likely explanation is:
A) Sympathetic nerve block B) Phrenic nerve block C) Subdural or subarachnoid injection D) Pneumothorax E) Recurrent laryngeal nerve block
9. Morphine can be injected intravenously, epidurally and intrathecally.
If you were to inject 5 mg of morphine intravenously and epidurally at different times in the same patient, which of the following actions of morphine will be MOST significant?
A) Greater urinary retention with intravenous administration B) Most intense analgesia with epidural administration C) Shorter duration of action with epidural administration D) Greater incidence of pruritus follows intravenous rather than neuroaxial
administration E) Shorter duration of analgesia following epidural administration
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
18
10. Morphine and Fentanyl are two of the most commonly used opioids for epidural administration. The two differ from each other in:
A) More intense and earlier onset of pruritus B) Delayed incidence of respiratory depression C) Faster onset of analgesia D) Longer duration of action E) Higher sensitivity of fentanyl analgesia reversal by naloxone
11. A 30-year-old man is scheduled for closed reduction of his left humerus. You
perform an interscalene block using thirty (30) ml of 0.25% of bupivacaine. Thirty minutes later the patient becomes apneic.
The MOST likely differential is:
A) Pneumothorax B) Phrenic nerve block C) Recurrent laryngeal nerve block D) Vertebral artery injection E) Subarachnoid injection
12. Celiac plexus block is indicated in patients with intractable visceral pain unmanaged
by traditional medications.
A successful block would be expected to:
A) Block parasympathetic fibers to pancreas B) Enhance peristalsis with diarrhea and manifestation of hypotension C) Block of sympathetic fibers to transverse colon D) Block erection and ejaculation E) Block somatic fibers to pancreas
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
19
13. A surgeon requests a Bier’s block for the release of left-hand carpal tunnel syndrome. Following tourniquet inflation to 300 mmHg you administer 50 ml of 0.5% lidocaine. However the surgeon decides to terminate the procedure ten (10) minutes after lidocaine administration.
What will be the MOST appropriate action at this time?
A) Administer 4 mg morphine and then deflate the tourniquet B) Deflate the tourniquet and administer ephedrine or phenylephrine to prevent
any hypotensive episodes C) Start deflating and reinflating the tourniquet several times in a minute D) Wait 20 minutes and then deflate and re-inflate immediately, and finally
deflate after 1 minute E) Wait an hour before deflating the tourniquet completely
14. Following a C-section with a successfully placed spinal block with hyperbaric 0.5%
bupivacaine, a 19-year-old female starts complaining of severe headache.
Which of the following characteristics associated with post-dural puncture headache (PDPH) will facilitate your diagnosis?
A) PDPH is more frequent in man than woman B) PDPH can never be prevented by prophylactic epidural blood patch C) There is a lower incidence of PDPH with Quincke and Pitkin spinal needles D) PDPH is less frequent if the needle bevel is parallel to the direction of dural
fibers E) PDPH is made worst in the supine position than in the sitting position
15. A 25-year-old woman is scheduled for tendon reconstruction of her second and third
fingers due to a recent dog bite. An axillary block is performed with 30 ml of 0.25% bupivacaine using a transarterial approach. However, 15 minutes later, the patient still complains of pain when the surgeon pricks the thenar eminence.
The MOST plausible explanation for continued sensitivity is inadequate block in the distribution of:
A) Median nerve B) Ulnar nerve C) Radial D) Musculocutaneous nerve E) Medial cutaneous nerve of the forearm
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
20
16. A 45-year-old man with 10 years history of insulin dependent diabetes (IDDM) and a 3 month prior history of inferior infarct is scheduled for transmetatarsal amputation of the first and second toes for osteomyelitis.
For a successful block all the following nerves should be blocked EXCEPT:
A) Sural B) Saphenous C) Superficial peroneal D) Deep peroneal E) Tibial
17. Intrathecal administration of morphine provides prolonged post-operative analgesia.
The MOST likely site of morphine action is:
A) Medulla B) Fourth ventricle C) Spinal nerve roots D) Cerebral cortex E) Substantia gelatinosa
18. A 69-year-old man with a 15 years history of IDDM is scheduled for debridement of
a thigh abscess under local and a MAC anesthesia. The surgeon infiltrates the area around the abscess with 30 ml of 2% lidocaine containing 1:200,000 epinephrine. However, the patient continues complaining of pain on incision at the site of the abscess.
The MOST plausible explanation for the lack of anesthesia includes:
A) Increased protein binding of lidocaine at the necrotic site B) Formation of increased ionized fraction of local anesthetics at the site of
injection due to local tissue acidosis C) Formation of increased non-ionized fraction of local anesthetics D) Limited diffusion of lidocaine due to vasoconstriction produced by
epinephrine E) Increased hydrolysis of lidocaine due to acidosis at the local necrotic site
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
21
19. An 80-year-old man with a medical history significant for CHF and a history of an MI three months ago, has had a transurethral resection of prostate (TURP) done under a spinal anesthetic with 10 mg bupivacaine (0.5%). Vital signs remained stable during the course of surgery, which lasted 60 minutes. Three minutes after the patient was transferred to a regular bed he developed nausea and vomiting and his blood pressure dropped to 65/40.
What is the MOST likely differential diagnosis?
A) An acute MI due to volume overload and development of severe CHF B) Bupivacaine induced sympathectomy leading to significant decrease in
preload due to peripheral vasodilation and venous pooling C) Dilutional hyponatremia D) Unrecognized excessive bleeding from prostate venous plexus E) Continued progression of sympathetic block
20. Prilocaine is not used in obstetrics regional anesthesia.
Which of the following side effects explains the MOST likely reason for this exclusion?
A) Prilocaine is not as safe and as potent as lidocaine B) Prilocaine can cause fetal methemoglobinemia C) Prilocaine has much shorter duration of action than lidocaine which precludes
its use D) Prilocaine is more toxic than bupivacaine and lidocaine E) Prilocaine is not metabolized by placenta
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
22
21. A 60-year-old female underwent successful hysterectomy for fibroids ten hours ago under lumbar epidural with lidocaine and fentanyl. For the last 7 hours, the patient had been receiving morphine by epidural infusion. The patient continues to complain of her inability to move her lower extremities. Neurological examination indicates an inability to flex the thighs or extend the knees.
What will be the MOST appropriate course of action at this time?
A) Reassure the patient not to worry about anything B) Stop the epidural morphine and reassess the patient 12 hours later C) Obtain MRI of the lumbar spine and request a neurology consult D) Take the epidural catheter out and reassess the patient a few hours later E) Reverse the effects of morphine with naloxone and reassess the patient an
hour later 22. A 3-year-old child is scheduled for a repair of hypospadias. The urologist requests a
caudal for postoperative pain control.
The landmarks for the block include:
A) Posterior superior iliac spine B) Coccyx C) Greater trochanter of the femur D) Iliac crest E) Sacral cornu
23. Local anesthetics can be administered via a variety of routes.
Which of the following characteristics of local anesthetics will be the MOST desirable for a surgery lasting several hours?
A) Lipid solubility B) Ratio of non ionized to ionized forms C) High molecular weight D) Increased protein binding E) Presence of ester linkages
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
23
24. A 20-year-old man is scheduled for closed reduction of a dislocated right humerus. Fifteen minutes later following a successful interscalene block with 40 ml of 0.25% bupivacaine the patient complains of facial flushing and sweating. Neurological examination shows unequal pupils.
The MOST plausible explanation for these findings is:
A) Horner’s syndrome due to cervical sympathetic block B) Injection into the vertebral artery with toxic manifestations of CNS symptoms C) Diffusion of local anesthetics to brain and block of cranial nerves D) Pneumothorax with symptoms strongly suggestive of hypoxic response E) Recurrent laryngeal nerve paralysis
25. Which of the following factors, when adjusted, will INCREASE the duration of
epidural block?
A) Using a local anesthetics with high protein binding B) Using increased volume of local anesthetics C) Using a local anesthetics with low pKa D) Adding sodium bicarbonate to local anesthetics E) Inserting a thoracic epidural
26. Following a successful vaginal hysterectomy under epidural anesthesia, a patient
complains of numbness and loss of dorsiflexion of the toes.
The MOST likely explanation is:
A) Epidural hematoma B) Lumbar abscess C) Saphenous nerve injury D) Sacral plexus injury E) Common peroneal nerve injury
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
24
27. Most of the actions of morphine are reversed by naloxone.
Which of the following effect of morphine is MOST resistant to naloxone administration?
A) Nausea and vomiting B) Pruritus C) Analgesia D) Respiratory depression E) Urinary retention
28. The primary determinant of the duration of a Bier block is:
A) Ratio of non ionized to ionized fraction of local anesthetics B) Duration of tourniquet inflation C) Protein binding of local anesthetics D) Volume of local anesthetics administered E) Technique of exsanguination
29. A 60-year-old male with 25 years history of IDDM is scheduled for below the knee
amputation using peripheral nerve blocks.
Which of the following combination of nerves SHOULD be blocked for a successful anesthesia?
A) Femoral, Lateral femoral cutaneous and Sciatic nerves B) Obturator, Femoral and Sciatic nerves C) Obturator, Lateral femoral cutaneous and Sciatic nerves D) Three-in-one block E) Sciatic nerve only
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
25
30. A 65-year-old man had a lumbar epidural placed for transurethral resection of the prostate (TURP). One hour into the procedure, he starts complaining of shortness of breath with associated abdominal pain. He is nauseated, tachycardic and hypertensive.
What is the appropriate NEXT step?
A) Inform the surgeon of possible bladder perforation and ask for termination of the procedure as soon as possible
B) Determine blood sodium concentration C) Administer Lasix D) Correct the hypertension with labetalol and ask the surgeon to use normal
saline as the irrigating fluid E) Treat the patient symptomatically and continue the surgery.
31. A 55-year-old man while undergoing TURBT for bladder tumor under hyperbaric
0.75% bupivacaine has sudden onset of a new atrial fibrillation with ventricular tachycardia.
The MOST appropriate treatment is:
A) Cardioversion B) Digoxin C) Esmolol D) Ouabain E) Verapamil
32. Manifestation of continued painless paralysis 24-hour later following placement of an
epidural is MOST consistent with which one of the following differentials?
A) Local anesthetics toxicity leading to nerve damages at the spinal nerve roots B) Adhesive arachnoiditis C) Anterior spinal artery stenosis D) Epidural hematoma E) Epidural abscess
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
26
33. Intractable pain due to unresectable pancreatic cancer is MOST effectively treated with:
A) Bilateral neurolytic intercostals blocks at T10-T12 B) Bilateral sympathetic block with phenol C) Celiac plexus block with alcohol D) Epidural block with alcohol E) Subarachnoid block with alcohol
34. An epidural is placed in a healthy patient. During aspiration clear fluid is noted to
drip back freely from epidural catheter.
Which of the following findings CORRECTLY identifies the associated fluid?
A) Precipitation when mixed with an equal volume of thiopental B) Acidic pH C) Glucose 100 mg/dL D) Sodium 154 mEq/L E) Pressure of 200 mmHg
35. A 10-month-old, 10 kg infant is scheduled for emergent inguinal hernia repair.
During the history and physical examination you find the patient had history of a running nose with low grade fever and dry cough a week ago. You decide to proceed with general anesthesia. For maintenance you use sevoflurane-nitrous oxide and oxygen. After extubation the patient develops inspiratory stridor with retraction while breathing 50% oxygen.
The MOST appropriate next action would be:
A) Reintubation after induction with volatile agents B) Administration of corticosteroids C) Administration of nebulized racemic epinephrine D) Observation E) Treatment with glycopyrrolate to dry up secretions
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
27
36. Arterial blood samples are most commonly utilized to assess the acid base status of patient’s blood.
Presence of a large air bubble in the syringe containing blood from a patient on 2L
O2 is consistent with which of the following errors?
PO2 PCO2 A) Increase Increase B) Decrease Increase C) Increase Decrease D) Decrease Decrease E) No Change No change
37. You are called by an ICU nurse to see a 75-year-old man with a history of aortic
stenosis scheduled for surgery the following day. The patient is complaining of chest pain and dizziness. His vitals include pulse rate of 120, BP 145/95 mmHg and respiration of 20.
The MOST appropriate therapeutic measure is administration of:
A) A liter of lactate Ringer’s solution intravenously B) Nitroglycerin intravenously to increase coronary circulation C) Midazolam to relieve his anxiety D) Supplemental oxygen E) Atenolol
38. Continuous positive airway pressure is used to improve oxygenation with an
improvement in arterial oxygen tension.
Which of the following patients with pulmonary disorder will benefit the MOST from continuous positive pressure ventilation?
A) A patient with severe kyphoscoliosis B) A chronic smoker with a history of COPD C) A patient with an acute episode of pulmonary edema following an abdominal
surgery D) A patient with partial pneumothorax E) A patient with a history of alveolar proteinosis
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
28
39. You are asked to examine a 5-year-old child in the emergency room with a six hour history of fever, difficulty in swallowing and inspiratory stridor. The child seems to be in acute distress and prefers a sitting position.
The BEST appropriate management is:
A) Keep a close watch on the child B) An orotracheal intubation in the operating room with volatile anesthetics in
the presence of an ENT physician C) A rapid sequence induction with propofol and succinylcholine D) An awake nasotracheal fiberoptic intubation E) Treatment with ampicillin and admission to the ICU
40. A newborn delivered by c-section under spinal anesthesia, is in respiratory distress.
You are unable to pass a fine suction catheter through either nostril. The MOST appropriate next action is:
A) Place an oral airway until surgical correction can be accomplished B) Intubate the patient C) Administer phenylephrine nose drops to constrict the nasal blood vessels D) Pass a catheter through the mouth to facilitate breathing E) Do nothing at this time as the newborn will learn mouth breathing
41. A 45-year-old woman with a history significant for hypertrophic obstructive
cardiomyopathy is scheduled for umbilical hernia repair. Spinal anesthesia is induced with 12.5 mg of hyperbaric bupivacaine containing 25 µg fentanyl. Five minutes after spinal anesthesia her blood pressure decreases to 65/45 mmHg and heart rate is 60 bpm with an associated ST elevation in the lateral leads.
The MOST appropriate action at this time is intravenous administration of:
A) 500 cc of Lactate Ringers solution B) 100 µg of phenylephrine C) 10 mg of metoprolol D) 2 mg of morphine E) 0.2 mg of glycopyrrolate
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
29
42. A 52-year-old woman is scheduled for bilateral mammoplasty. In view of history of obesity and past difficult intubation, an awake fiberoptic nasal intubation is planned. During her preparation for intubation you inject 3 ml of 2% lidocaine bilaterally 1 cm below each cornu of hyoid bone.
The MOST likely reason for this injection is:
A) Prevent laryngospasm during awake nasal intubation B) Block all sensation below the vocal cords C) Anesthetize the inferior laryngeal nerve D) Paralyze the posterior arytenoids muscle E) Anesthetize the glossopharyngeal nerve
43. A 3-year-old child underwent tympanoplasty and middle ear exploration under
general anesthesia. The child had recently recovered completely from an upper respiratory tract infection. Following extubation the child is crying with retraction of the upper thoracic muscles.
The MOST appropriate therapy is:
A) Reintubation with a smaller size endotracheal tube B) Positive pressure ventilation with a face mask C) Manage the child conservatively with nebulized racemic epinephrine (0.5 ml
of a 2.25% solution in 2.5 ml of normal saline). D) Intravenous administration of dexamethasone (0.25 – 0.5 mg/kg) E) Observation of the child in ICU
44. A 60-year-old man with a history significant for hypertension, coronary artery
disease, is under general anesthesia for a laparoscopic cholecystectomy. Half an hour later during the procedure the patient develops expiratory wheezing.
Which of the following is the MOST appropriate initial management effort to decrease wheezing?
A) Position the patient in reverse Trendelenburg position B) Administer lidocaine 100 mg via the endotracheal tube C) Apply a 5 cm positive-end-expiratory pressure (PEEP) D) Administer 0.5 ml of epinephrine with1:1000 dilution subcutaneously E) Manage the wheezing with mist therapy and racemic epinephrine solution
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
30
45. Adverse effects of obesity are associated with increased morbidity and mortality.
Which of the following components of pulmonary volumes or function tests is altered the MOST in obesity?
A) Total lung capacity (TLC) B) Forced expiratory volume at 1 second (FEV1) C) Maximal midexpiratory flow rate (MMEFR) D) Functional residual capacity (FRC) E) Ratio of dead space to tidal volume
46. You are asked to examine a 5-kg neonate in an intensive care unit after closure of
omphalocele. A chart review discloses minimal blood loss during the surgery. His vitals at the time of examination are as follows:
Heart rate - 145 bpm Blood pressure - 50/25 mmHg Arterial blood gas on FiO2 of 0.6 PO2 65 mmHg, PCO2 40 mmHg, pH 7.26 Urinary output during surgery 1 ml/kg/hr. Presently no urine output for the last one
hour.
What is the MOST appropriate next step in the management of this patient?
A) Fluid challenge 10 ml/kg with lactate Ringers solution B) Reoperation to relieve abdominal pressure C) Diuresis with Furosemide D) Observation for few hours before making any further decision E) A chest x-ray to delineate the possible cause of acidosis and hypotension
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
31
47. A 26-year-old man with the diagnosis of pheochromocytoma is scheduled for adrenalectomy. The patient had been on phenoxybenzamine 100 mg bid for a week. The surgeon informs you that the patient has adequate block of alpha and beta receptors.
Which one of the following statements is the MOST accurate for adequate block?
A) The physical examination should show postural hypotension, nasal stuffiness, decreased sweating and stable vital signs
B) The patient is adequately blocked based on the history provided by the surgeon
C) No further evaluation is necessary because you plan a deep opioid anesthesia D) Patient is not appropriately blocked as he should have been started on alpha-
methyltyrosine at least a week before the surgery E) Patient’s urine should be tested for catecholamine before proceeding with the
surgery 48. Which one of the following situations will present with MOST dangerous situation if
a vaporizer is filled with a wrong agent?
A) Enflurane-specific vaporizer is filled with halothane B) Halothane vaporizer is filled with enflurane C) Isoflurane vaporizer is filled with halothane D) Halothane vaporizer is filled with isoflurane E) Halothane vaporizer is filled with methoxyflurane
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
32
49. Four hours after vaginal delivery a 2200-g male neonate vital signs are as follows:
Respiratory rate - 50/min Pulse rate - 115 bpm Arterial blood gas at room air: PO2 60 mmHg; PaCO2 44 mmHg; pH 7.33
Baby’s mother had received 75 mg of meperidine IM nearly 2 1/2 hours before
delivery.
What is the MOST appropriate step in the management of this patient?
A) Increase the FiO2 to 40% B) Intubate the patient and start mechanical ventilation C) Titrate the respiratory rate of the patient by intravenous administration of
naloxone D) Observe the patient E) Induce diuresis and acidify urine to increase elimination of meperidine
50. A 20-year-old man has sustained abdominal and anterior chest wall trauma. A left
pneumothorax has been controlled by a chest tube. Immediate laparotomy is planned for bleeding from an unknown site.
What will be the next MOST appropriate action in the management of this patient?
A) The chest tube should be clamped during general anesthesia B) High concentration of nitrous oxide with volatile anesthetics can be used C) Positive-pressure ventilation with high tidal volume and low rate should be
used D) Avoid nitrous oxide because it will increase intrapleural pressure and the size
of pneumothorax E) Place another chest tube on the right side to avoid tension pneumothorax
during the surgery
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
33
51. Carbon monoxide (CO) poisoning has been reported in patients anesthetized on Monday morning especially when continuous high gas flows (> 10L/min) have been allowed to exist on an anesthesia machine over the weekend.
The inhaled anesthetic capable of producing the GREATEST concentrations of CO is:
A) Halothane B) Isoflurane C) Sevoflurane D) Desflurane E) Xenon
52. Which of the following BEST describe the effects of nitrous oxide alone on cerebral blood flow (CBF), cerebral metabolic rate for oxygen consumption (CMRO2), and intracranial pressure (ICP)?
A) CBF increases, CMRO2 decreases, ICP increases B) CBF decreases, CMRO2 decreases, ICP increases C) CBF increases, CMRO2 increases, ICP increases D) CBF increases, CMRO2 decreases, ICP decreases E) CBF no change, CMRO2 no change, ICP no change
53. The active metabolic byproduct of meperidine with potential toxic effects capable of inducing seizures is:
A) Laudanosine B) Meperidinic acid C) Normeperidinic acid D) Normeperidine E) Norcodeine
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
34
54. A 44-year-old morbidly obese patient requires orotracheal intubation. An awake fiberoptic assisted tracheal intubation techniques will be used. Several peripheral nerve blocks will be utilized to anesthetize the airway.
Which of the following nerves assures that the mucosa from the epiglottis to the cord will be anesthetized?
A) Recurrent laryngeal nerve B) Glossopharyngeal nerve C) Sphenopalatine nerve D) Superior laryngeal nerve E) Lingual nerve
55. Regarding normal thermoregulation, afferent cold input to the hypothalamus is
primarily by which nerve fiber classification?
A) A-alpha B) A-beta C) A-delta D) B E) Unmyelinated C-fiber
56. Functional residual capacity (FRC) is composed of which of the following lung volumes?
A) Inspiratory reserve volume (IRV) + tidal volume (TV) B) Inspiratory reserve volume (IRV) + expiratory reserve volume (ERV) + tidal
volume (TV) C) Inspiratory reserve volume (IRV) + residual volume (RV) D) Expiratory reserve volume (ERV) + tidal volume (TV) E) Expiratory reserve volume (ERV) + residual volume (RV)
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
35
57. Which of the following conditions are believed to augment the oculocardiac reflex?
A) Hypercarbia B) Hypocarbia C) Deep anesthetic state D) Hypertension E) Hypotension
58. A 74-year-old female with a history of atrial fibrillation and on chronic warfarin
therapy is scheduled for emergency surgery for correction of a small bowel obstruction.
What is the BEST therapy to urgently reverse the effects of warfarin?
A) Administer vitamin K B) Administer protamine C) Administer albumin D) Administer fresh frozen plasma E) Administer cryoprecipitate
59. A 54-year-old male is undergoing a craniotomy for a posterior fossa tumor. The
patient will be placed in a sitting position for the surgical procedure.
Monitoring of which of the following would be the MOST sensitive in detecting a venous air emboli?
A) Measuring oxygen saturation B) Measuring end-tidal carbon dioxide (CO2) C) Measuring end-tidal carbon monoxide (CO) D) Measuring end-tidal nitrogen (N2) E) Measuring pulmonary artery pressures
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
36
60. Which of the following maneuvers would result in a DECREASE in anatomical dead space?
A) Supine to upright position B) Neck extension C) Use of bronchodilators D) Ventilation with a mask E) Tracheal intubation
61. Which of the following BEST describes the systolic and diastolic pressures of
peripheral arteries such as the dorsalis pedis artery when compared to the aortic root?
A) No change in systolic and diastolic pressures B) Higher systolic and diastolic pressures C) Lower systolic and diastolic pressures D) Lower systolic pressure and higher diastolic pressures E) Higher systolic pressure and lower diastolic pressure
62. Which of the following medication used for induction is associated with suppression
of adrenal function?
A) Sodium thiopental B) Propofol C) Etomidate D) Methohexital E) Ketamine
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
37
63. A 23-year-old female is scheduled for a septorhinoplasty. This is her first surgical procedure and denies ever having anesthesia. Following propofol for induction and mivacurium for muscle relaxation she was intubated without any complications. Anesthesia consisted of desflurane/nitrous oxide/oxygen combination. Fentanyl was given as an adjuvant to the anesthesia. One and half hour later, no muscle twitch could be elicited by stimulating the ulnar nerve with a nerve stimulator.
Which of the following BEST explains the prolonged muscle paralysis?
A) Synergistic effects of desflurane B) Decrease renal clearance of mivacurium C) Hypothermia D) Atypical pseudocholinesterase E) Non-specific esterase deficiency
64. Which of the following pseudocholinesterase genotypes is associated with a normal
dibucaine number?
A) Ea Ea B) Ea Eu C) Eu Ea D) Eu Eu E) Ef Ea
65. A 66 year-old male patient with type II diabetes and end stage renal disease is
schedule for amputation of his left foot. He refuses regional anesthesia and prefers general anesthesia. Which of the following muscle relaxants is best avoided in this patient?
A) Succinylcholine B) Atracurium C) Cis-atracurium D) Rocuronium E) Pancuronium
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
38
66. A 60-year-old male with colon cancer is schedule for a colon resection. The night before he underwent a “bowel prep”. There is concern that the patient may have developed hypokalemia.
Which of the following ECG changes would MOST be indicative of hypokalemia?
A) Peaked T waves B) Delta waves C) Widen QRS complexes D) Prominent U waves E) Loss of P waves
67. A 25-year-old male sustained a spinal cord injury at the level of T-10.
What is the LATEST that succinylcholine could be safely used?
A) Less than 24 hours post-injury B) 48 to 72 hours post-injury C) 1 week post-injury D) 4 weeks post-injury E) 4 months post-injury
68. Which of the following intravenous agents does NOT mediate its effect through the
gamma-aminobutyric acid (GABAA) receptor?
A) Methohexital B) Sodium thiopental C) Propofol D) Etomidate E) Ketamine
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
39
69. A 19-year-old underwent a cesarean section following a prolong labor. The surgical procedure was performed under regional anesthesia. After delivery of the infant and placenta, the uterus remained hypotonic.
What would be the NEXT appropriate treatment?
A) Administer phenylephrine B) Administer neostigmine C) Administer desmopressin D) Administer oxytocin E) Administer vasopressin
70. After delivery of an infant and placenta, the uterus remained hypotonic. Oxytocin
was therefore given intravenously.
Which of the following represents a side effect due to oxytocin?
A) Hypotension B) Hypertension C) Bradycardia D) Hypoxia E) Diuresis
71. A patient is undergoing laser ablation of laryngeal papillomas. Suddenly a fire is
ignited in the endotracheal tube.
What is the appropriate NEXT step in this situation?
A) Remove the endotracheal tube B) Flood the field with saline C) Switch from oxygen to air D) Stop the administration of volatile anesthetics E) Stop ventilation
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
40
72. A 16-year-old with a significant history of asthma is scheduled for a tonsillectomy.
All of the following medications would result in histamine release EXCEPT:
A) Morphine B) Meperidine C) Sodium thiopental D) Cis-atracurium E) Mivacurium
73. A 32-year-old muscular male was emerging from anesthesia when his endotracheal
tube was removed prematurely. Shortly after extubation the patients became hypoxic despite making respiratory efforts. After a failure to correct the hypoxemia by mask ventilation, the patient received succinylcholine and was re-intubated. After intubation oxygen saturation remained at 90% while on 100% oxygen.
His continued hypoxemia is MOST likely due to which of following?
A) Intubation of the esophagus B) Congestive heart failure C) Residual paralysis by succinylcholine D) Aspiration of gastric contents E) Pulmonary edema
74. A 16-year-old female is undergoing surgery for correction of spinal scoliosis. General
anesthesia is being provided with an opioid infusion (fentanyl) and with 0.5 MAC of sevoflurane. The patient is in a prone position and receiving rocuronium for muscle paralysis. Two hours into the surgical procedure, a sudden drop in end-tidal carbon dioxide from 35 mmHg to 18 mmHg is noticed followed by hypotension.
Which of the following has MOST likely occurred?
A) Sevoflurane induced hypotension B) Venous air embolus C) Capnography malfunction D) Spinal cord ischemia E) Malignant hyperthermia
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
41
75. A patient had a spinal anesthetic with 5% lidocaine for a transurethral resection of the prostate (TURP) and was place in the lithotomy position. Following the procedure the patient complained of bilateral buttock pain.
What is the MOST likely etiology?
A) Femoral neuropathy B) Cauda equina syndrome C) Obturator neuropathy D) Epidural hematoma E) Transient neurologic syndrome
76. Mannitol’s PRIMARY site of action in the kidney is:
A) Proximal convoluted tubule B) Medullary portion of ascending loop of Henle C) Cortical portion of ascending loop of Henle D) Distal convoluted tubule E) Collecting duct
77. The prompt awakening that occurs after an intravenous induction dose of sodium
thiopental can be attributed to:
A) Redistribution from the brain to the blood B) Redistribution into fat tissue C) Redistribution into skeletal muscle D) Cytochrome P450 metabolism E) Renal excretion
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
42
78. In attempting an awake fiberoptic assisted intubation, a superior laryngeal nerve block will be preformed.
Which of the following is an important landmark to perform this nerve block?
A) Chassaignac tubercle B) Base of the posterior tonsillar pillar C) Cricothyroid membrane D) Greater cornu of the hyoid cartilage E) Transverse process of C6
79. Soon after induction, intraoperative hypothermia begins to occur with the initial rapid
drop in temperature attributed to:
A) Convection to the environment B) Conduction to cold surfaces C) Radiation to the environment D) Decrease metabolism E) Redistribution of core temperature
80. An orthopedic surgeon has referred to your pain clinic a 46-year-old female patient with a complaint of severe pain involving her right lower extremity. She explains that she experienced a moderately severe right ankle sprain approximately 3 months ago that appeared to have had resolved, but shortly after, began to experience a burning aching pain that involved her lower extremity. On examination her leg is edematous and her skin appears shinny. She has difficulty flexing her foot.
With her history and signs and symptoms on examination, the MOST likely diagnosis is:
A) Complex Regional Pain Syndrome I B) Complex Regional Pain Syndrome II C) Fibromyalgia D) Peripheral neuropathy E) Raynaud’s disease
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
43
81. A patient has been diagnosed with Complex Regional Pain Syndrome, Type I in the acute (hyperemic) stage.
Which of the following would be LESS likely to be present?
A) Edema B) Allodynia C) Hyperalgesia D) Increase skin temperature E) Osteoporosis
82. A 32-year-old patient had an above the elbow amputation of his right arm and is
experiencing phantom limb sensation one month later.
Which of the following is the MOST appropriate management?
A) Trial of opioids B) Use of nonsteroidal anti-inflammatory drugs C) Interscalene block D) Transcutaneous electrical nerve stimulation (TENS) E) No treatment
83. A patient with reflex sympathetic dystrophy experiences pain with a light touch of a
feather.
This phenomenon is called:
A) Hyperalgesia B) Hyperesthesia C) Hypoalgesia D) Allodynia E) Analgesia
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
44
84. A patient is referred to your pain clinic by an oncologist for relief of severe abdominal pain. The patient is diagnosed with pancreatic cancer that is inoperable.
Which of the following interventions would be MOST appropriate?
A) Stellate ganglion block B) Celiac plexus block C) Superior hypogastric plexus block D) Cervical plexus block E) Lumbar sympathetic block
85. Following a celiac plexus block, the MOST common complication is:
A) Bradycardia B) Hypotension C) Renal injury D) Hematoma E) Paraplegia
86. In performing a brachial plexus block by an axillary approach for a distal radial
fracture repair, which of the following nerve MAY need supplementation?
A) Median nerve B) Radial nerve C) Ulnar nerve D) Musculocutaneous nerve E) Axillary nerve
87. After performing an axillary block of the brachial plexus, which of the following
sensory distribution would be consistent with a spared musculocutaneous nerve?
A) Lateral part of the palm and thenar eminence B) Thumb, index and middle finger, with lateral half of ring finger C) Medial aspect of the hand D) Lateral aspect of the forearm E) Medial aspect of the forearm
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
45
88. A 32-year-old female had a total thyroidectomy two days ago. Since her surgery she has complained of hoarseness in her voice. Endoscopic exam of her vocal cords showed her left vocal cord in the paramedian position.
This is consistent with which type of nerve injury?
A) Unilateral recurrent laryngeal nerve injury B) Bilateral recurrent laryngeal nerve injury C) Unilateral vagal nerve injury D) Unilateral superior laryngeal nerve injury E) Bilateral superior laryngeal nerve injury
89. A patient with postherpetic neuralgia presents with severe unilateral back pain.
Which of the following medication is the MOST effective in the management of this patient’s pain?
A) Ibuprofen B) Morphine C) Amitriptyline D) Aspirin E) Topical lidocaine
90. A 43-year-old female with a history of diabetes is scheduled for an emergent
cholecystectomy for a gangrenous gallbladder. On physical exam, she is noted to be obese, but airway appears to be normal.
What is her ASA classification?
A) ASA physical status I B) ASA physical status I-E C) ASA physical status II D) ASA physical status II-E E) ASA physical status III
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
46
91. All of the following neurophysiologic effects of inhaled anesthetics are true EXCEPT:
A) All of the potent inhalational agents depress CMR (Cerebral Metabolic Rate) in a linear fashion
B) Isoflurane causes iso-electric EEG at doses used clinically C) All of the potent inhalational agents increase the CBF (Cerebral Blood Flow)
in a dose dependent manner D) Halothane causes the greatest increase in the CBF per MAC (Minimum
Alveolar Concentration) multiple E) Isoflurane produces insignificant change in the CBF at 1 MAC doses
92. Factors that influence the correlation between set tidal volume and exhaled tidal
volume during intra-operative controlled ventilation include all of the following EXCEPT:
A) The flow meter settings B) The expiratory time C) The compliance of the breathing circuit D) Ventilatory rate E) Circuit leaks
93. The following statements about the cardiovascular effects of potent volatile anesthetics are true EXCEPT:
A) Halothane causes profound depression of the myocardial contractility B) At anesthetic levels >1 MAC, desflurane is associated with 10-20% increase
in heart rate C) Recent evidence indicates volatile agents exert important cardio-protective
effects during myocardial ischemia D) Compared to adenosine volatile anesthetics are only weak coronary
vasodilators E) Desflurane and sevoflurane cause dose-dependent increase in the myocardial
contractility
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
47
94. A 20-year-old female patient is admitted for a diagnostic biopsy of an anterior mediastinal mass. She has a history of a cough for one month. There is no history of dyspnea, stridor or noisy breathing. Chest x-ray shows a massive mediastinal mass filling more than two-thirds of the chest. A computed tomographic scan confirms this finding and also shows compression of both main bronchi. The following statements are TRUE regarding the anesthetic management of this patient EXCEPT:
A) Rapid sequence induction should be planned with thiopentone and succinylcholine
B) An awake fiberoptic intubation under topical anesthesia of the oropharynx should be planned
C) Preoperatively, pulmonary flow volume loop studies should be carried out in the supine and upright positions
D) Total or near total airway obstruction may occur during induction or emergence from anesthesia
E) Large bore peripheral intravenous cannulae should be placed in the lower extremities
95. The major anatomic differences between the neonatal and adult airway include all of the following EXCEPT:
A) An infant’s larynx is situated higher in the neck B) An infant’s tongue is closer to the roof of the mouth and easily obstructs the
airway C) An infant’s epiglottis is narrower and angled away from the trachea D) An infant’s axis of the vocal folds is perpendicular to the trachea E) The narrowest portion of an infant’s larynx is the cricoid cartilage
96. Which of the following is NOT a characteristic of a VDD pacemaker
A) Is capable of pacing the ventricles only B) Provides AV synchrony C) Provides for a physiological rate increase D) Is a dual chamber device with two leads E) Can sense electrical activity in both the atrium and the ventricle
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
48
97. The following statements about cardiovascular effects of drugs that are used during the reversal of nondepolarizing neuromuscular block are true EXCEPT:
A) Atropine induces its vagolytic effect much more rapidly than does
glycopyrrolate. B) Administration of glycopyrrolate with edrophonium may result in an initial
bradycardia C) Anticholinesterases should be used with caution in patients with autonomic
neuropathy D) When cardiac arrhythmias are a concern, atropine may be preferable to
glycopyrrolate E) To minimize cardiovascular changes, atropine is better suited with
edrophonium
98. How much epinephrine l:1000 should be added to 20 ml of local anesthetic
solution to obtain a 1:200,000 concentration of epinephrine?
A) 0.10 ml B) 0.15 ml C) 0.20 ml D) 0.50 ml E) 0.60 ml
99. A 60-year-old patient status post colectomy is in the PACU and has oxygen delivered
through nasal prongs at a flow rate of 5L/min. What is the maximum inspired concentration of oxygen (FiO2) that can be achieved by nasal prongs at a flow rate of 5L/min?
A) 0.28 B) 0.32 C) 0.36 D) 0.40 E) 0.50
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
49
100. A 52-year-old man in PACU has difficulty in maintaining his oxygen saturation above 80% on simple face mask with an oxygen flow rate of 5L/min. The patient had a right upper lobectomy 15 minutes ago. Physical examination is unremarkable and chest is clear to auscultation. What is the next MOST appropriate step in the management of this patient?
A) Change the face mark to partial rebreathing mask B) Change the face mask to non-rebreathing mask C) Change the face mask to venturi face mask D) Change to nasal cannula with 10L oxygen flow E) Re intubate the patient
101. A 20-year-old man is undergoing a right adrenalectomy for pheochromocytoma under isoflurane–nitrous oxide and oxygen. Fifteen minutes in the procedure, his blood pressure increases acutely from 150/85 to 250/150 with presentation of premature ventricular contractions. The MOST appropriate management includes:
A) Administration of nitroprusside and propanolol B) Switching isoflurane to halothane C) Switching to a long acting muscle relaxant D) Using propanolol followed by phentolamine E) Increasing the concentrations of volatile anesthetics and opioids
102. A 20-year-old male is scheduled for bilateral inguinal hernia repair. Past history indicates the presence of ventricular septal defect. Which of the following hemodynamic phenomena is MOST likely?
A) Induction with intravenous anesthesia is delayed B) Induction with volatile anesthesia is accelerated C) Shunting is increased by positive pressure ventilation D) Shunting is increased by systematic hypotension E) Shunting is decreased by increase in systematic vascular resistance.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
50
103. A 75-year-old man received 15 units of packed red blood cells (14 days old) during repair of abdominal aneurysm over a course of seven hours.
Which of the following hemodynamic changes will be present at the end of surgery?
A) Thrombocytopenia leading to prolonged bleeding time and decreased plasma concentrations of labile factor V sufficient to prolong prothrombin time
B) Significant decrease in serum concentrations of calcium causing symptomatic hypocalcemia
C) Significant hyperkalemia to produce EKG changes and cardiac arrhythmia D) Significant metabolic acidosis which may need correction with sodium
bicarbonate E) No changes in the concentration of 2, 3 – diphosphoglycerate
104. Chronic obstructive lung diseases have some component of impairment in diffusion capacity. Which of the following statements is MOST accurate?
A) By increasing PAO2, PaCO2 increases B) Positive end expiratory pressure is more effective in increasing PaO2 than an
increase in FiO2 C) Increase in pulmonary compliance is more effective way of increasing PaO2 D) Increase in pulmonary blood flow is more effective way of increasing PaO E) Increase in cardiac output is more effective way of increasing PaO2
105. Assume during a laparotomy procedure you use halothane – nitrous oxide – oxygen as a maintenance agent for general anesthesia. The PaO2 drops from 325 mmHg to 225 mmHg at FiO2 of 0.5 in 1 1/2 hours. Physical examination is unchanged. What is the MOST likely reason?
A) Increased ventilation/perfusion mismatch B) Decreased cardiac output C) Sepsis D) Increased uptake of volatile agents E) Increased dead space to tidal volume ratio
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
51
106. Six hours following parathyroidectomy a 30-year-old woman has changes in the quality of her voice. There is no inspiratory stridor. Serum level of calcium is 9mg/dl. What is the MOST appropriate management?
A) Re-intubate the patient B) Administer calcium gluconate C) Consider tracheostomy D) Observe in ICU for 24 hours E) Administer nebulized Racemic epinephrine solution
107. A 29-year-old man is scheduled for ankle surgery following a fall from stairs while on work. During pre-operative evaluation you notice bruises under the skin. The patient has a history of nose and gum bleed. These signs are MOST consistent with history of:
A) Clotting factor disorder B) Vitamin K deficiency C) Von Willebrand’s disease D) Primary hemostasis defect E) Use of antiplatelet agents
108. Which of the following is the MOST common cause of acquired platelet dysfunction?
A) Uremia B) Alcoholism C) Antiplatelet agents D) Fibrin degradation products (FDPs) E) Vitamin K deficiency
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
52
109. In an 80-year-old ICU patient with septic shock and disseminated intravascular coagulation (DIC), which of the following drugs SHOULD be avoided?
A) Aminocaproic acid B) Tranexamic acid C) Aprotinin D) All of the above E) None of the above
110. Line isolation transformer can protect a patient from leakage current and microshock
hazards BECAUSE:
A) It can detect all faults B) It can detect small currents even in the pacing wires C) It has a three-wire grounding system D) It is an ungrounded system on the secondary side of transformer E) None of the above
111. A 78-year-old woman is undergoing total colectomy for colon cancer. His vitals are
stable. An hour later in the procedure the five lead EKG changes from sinus rhythm to ventricular tachycardia with the rate of 140 bpm. Blood pressure changes from 140/88 to 75/45 mmHg. What is the MOST appropriate next step in the management of this patient?
A) External DC cardioversion B) Get a 12-lead EKG and then plan the next step C) Administer phenylephrine intravenously D) Administer amiodarone intravenously E) Administer a calcium channel blocker
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
53
112. A 25-year-old woman with no previous history of surgery underwent umbilical hernia repair under general anesthesia with propofol and 140 mg of succinylcholine. After an hour following completion of surgery patient had inadequate skeletal muscle strength to permit extubation of the trachea.
Which of the following is the MOST likely explanation of her weakness?
Cholinesterase Activity Dibucaine number
A) Normal 45 B) Low 45 C) Normal 80 D) Low 80 E) Low 20
113. During fetal heart rate monitoring in a 25-year-old woman, fetal heart rate decreases uniformly from 150 bpm to 120 bpm during uterine contractions.
The MOST likely explanation is?
A) Decrease in maternal blood oxygen tension B) Compression of maternal great vessels C) Compression of fetal head D) Compression of umbilical cord E) Excessive uterine activity
114. A 30-year-old woman with a transection of spinal cord at C6 level sustained after a motor vehicle accident 2 years ago is scheduled for a urology procedure. You plan a general anesthesia.
Which of the following hemodynamic parameters will show the MOST variations during the procedure?
A) Heart rate B) Regulation of body temperature C) Urine output D) Blood PaCO2 and PaO2 E) Postoperative shivering
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
54
115. During preoperative evaluation a 60-year-old man with a history of small cell carcinoma of right upper lobe scheduled for mediastinoscopy, complains of bilateral upper and lower extremities weakness which improves with exercise.
This patient will show:
A) Increased response to anticholinesterases B) Increased sensitivity to depolarizing and nondepolarizing muscle relaxants C) Gradual decreased muscle strength with exercise D) Increased muscle strength following administration of prednisone E) Resolution of symptoms following administration of immunosuppressive
agents 116. An 80-year-old man is scheduled for excision of a 3-cm localized lesion on forehead
(basal cell carcinoma) as an outpatient surgery the following day. As his anesthesiologist you SHOULD:
A) See the patient sometime today for preanesthetic evaluation B) Call the patient and instruct him to take clear fluids for 12 hours before
surgery C) Order EKG, CXR, CBC and electrolytes before surgery D) Order oral lorazepam and instruct him to take the night before the surgery E) See the patient at the time of surgery
117. Which of the following group of patients is NOT at an increased risk for surgical complications performed at an outpatient setting?
A) Patients with a history of prolonged postoperative nausea and vomiting B) Patients with a history of immunosuppressive diseases C) Neonates born prematurely D) Presently healthy neonates treated for respiratory distress syndrome at birth E) Elderly patients with a history of hypertension and diabetes
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
55
118. Magnesium used in the treatment of pregnancy-induced hypertension, can enhance the neuromuscular blockade during general anesthesia.
Which of the following agents may REVERSE this effect?
A) Potassium B) Calcium C) Sodium D) Neostigmine E) Lidocaine
119. Two days after thyroidectomy under general anesthesia a 27-year-old woman is found confused and disoriented. Her neck is extended with jaw rigidity, inspiratory stridor and thready pulse. What should be the next MOST appropriate course of action in the management of this patient?
A) Paralyze and intubate the patient B) Administer Ativan intravenously C) Return the patient to the operating room for reexploration of her neck D) Administer oxygen and intravenous calcium gluconate E) Face mask her with oxygen and order stat electrolytes and CBC
120. A 25-year-old man is undergoing general anesthesia for cholecystectomy. Blood gas
analysis shows PaO2 of 80 mmHg, PaCO2 of 50 mmHg and a mixed expiratory PCO2 of 25 mmHg with tidal volume of 600 ml. Which of the following statements is TRUE?
A) His physiologic dead space is 300 ml due to increased atelectasis B) His physiologic dead space is 300 ml with no changes in V/Q mismatch C) His physiologic dead space is 300 ml due to increased in V/Q mismatch D) His physiologic dead space is 450 ml due to increase in V/Q mismatch E) There is an increase in anatomic dead space with no changes in physiologic
dead space
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
56
121. The left ventricle is perfused during diastole. Which of the following parameters BEST estimate left ventricular subendocardial
perfusion pressure?
A) The difference between mean arterial and central venous pressures B) The difference between diastolic arterial and central venous pressures C) The difference between systolic and central venous pressures D) The difference between diastolic arterial and pulmonary wedge pressures E) The difference between diastolic arterial and pulmonary artery diastolic
pressures 122. A 40-year-old 60-kg woman with a history of myasthenia gravis had thymectomy
done under general anesthesia two hours ago. General anesthesia was induced with fentanyl, propofol and rocuronium (30 mg) followed by intubation. Patient is alert, oriented, and cooperative and follows commands two hours post-surgery. Her present ventilator settings include: intermittent mandatory ventilation (IMV) at a rate of 5/min., tidal volume of 700 ml and FIO2 of 0.5. The patient is breathing over the ventilator at a rate of 20/min. MIF is – 17 cm H2O. Her heart rate is 80 bpm and blood pressure 130/75. ABG shows PaO2 of 130 mmHg, PaCO2 of 48 mmHg and pH of 7.34. What will be the next MOST appropriate course of action in the management of this patient at this time?
A) Reduce the IMV rate to 2/min. and watch for the next 4 hours B) Reverse the effects of rocuronium with neostigmine and glycopyrrolate and
then extubate after 15 minutes C) Administer 2 mg edrophonium intravenously and recheck MIF D) Keep the patient intubated till the return of full muscle strength E) Start the patient on intramuscular anticholinesterases and recheck vitals
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
57
123. A 25-year-old man with known history of hemophilia A, is scheduled for open reduction of his left knee following a fall. His HCT is 29 and level of circulating factor VIII concentration is 5% of the normal. What is the MOST appropriate preoperative and intraoperative course of action in the management of this patient?
A) Administration of fresh frozen plasma to increase factor VIII to 50% of normal
B) Administration of fresh whole blood to increase factor VIII to 50% normal C) Administration of recombinant factor VIII to increase factor VIII to 50%
normal D) Administration of cryoprecipitate to increase factor VIII to 50% of normal E) Postponement of surgery till HCT and factor VIII levels are normalized
124. A 25-year-old man is brought to the ER by paramedics. The patient has burns over
the face, head, neck and both hands. Physical examination shows facial burns, singed facial and nasal hair and redness of
oropharyngeal and nasopharyngeal mucosa. There are no signs of stridor, grunting or hoarseness. In the management of the airway in this patient what is the MOST appropriate next step?
A) Immediate placement of humidified 100% oxygen by face mask B) Endotracheal intubation as soon as possible C) Observation and intubation if the signs of respiratory obstruction appears D) Checking the carboxyhemoglobin and methemoglobin levels in the blood and
intubation if carboxyhemoglobin level is greater than 15% E) Intubation if PaO2 level is less than 100 mmHg at FiO2 of 0.4
125. Which combination of drugs freely penetrates the blood –brain- barrier?
A) Physostigmine, scopolamine, carbon-dioxide B) Neostigmine, glycopyrrolate, carbon-dioxide C) Atropine, glycopyrrolate, bicarbonate D) Scopolamine, atropine, glycopyrrolate E) Edrophonium, atropine, bicarbonate
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
58
126. An 80-year-old man with a history of hypertension and peripheral edema is scheduled for inguinal hernia repair. His medications include spironolactone and furosemide.
His pre-operative evaluation should include tests for:
A) Hyperkalemia B) Hypercalcemia C) Acidosis D) Hyponatremia E) Hypoglycemia
127. Which of the following clinical situations will be contraindications to the use of
metoclopramide as a premedication?
A) Intestinal obstruction, tremors, hepatic dysfunction B) Diabetic gastroparesis, esophageal reflux C) Chemotherapy induced emesis D) Patients on digoxin and insulin E) Pregnancy induced emesis
128. A 50-year-old man complains of severe pain on left chest wall. He has a history of
small cell carcinoma involving his left lung and active “shingles” in the distribution of T6-8 nerves on the right thoracic chest wall. During pulmonary function tests, which of the following parameters is MOST likely to be accurate?
A) Forced expiratory volume in one second (FEV1) B) Maximum mid-expiratory flow (MMEF) C) Negative inspiratory pressure D) Peak expiratory flow rate E) Maximum breathing capacity
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
59
129. A 60-year-old, 150 kg man had an episode of severe cough during induction of anesthesia for a right hip replacement. Three minutes later his oxygen saturation as measured through the pulse oximeter dropped to 80 from 100. Oral suctioning noted copious secretions and vomitus in his mouth.
Physical examination reveals bilateral wheezing. Arterial blood gasses on FiO2 of
45% are: PaO2 of 52 mmHg, PaCO2 of 50 mmHg, pH 7.32. In the management of this patient what is the next MOST appropriate step?
A) Airway suctioning, intubation, mechanical ventilation with PEEP, cancellation of surgery and observation in ICU
B) Airway suctioning, intubation, saline lavage and continuation of surgery C) Intubation followed by administration of steroids and antibiotics D) Intubation, cancellation of surgery and administration of albuterol E) Airway suctioning, intubation, mechanical ventilation and continuation of
surgery
130. A 5-year-old child who aspirated a small piece of a toy into his right bronchus is anesthetized with sevoflurane in oxygen.
The ENT surgeon uses a ventilating bronchoscope to remove the foreign body.
During several attempts to remove the foreign body, it becomes more difficult to ventilate the child. The MOST appropriate emergent next step in the management of this patient is?
A) Perform emergent tracheostomy B) Push the foreign body into right upper bronchus C) Deepen the level of anesthesia with volatile anesthetics D) Paralyze the child with a muscle relaxant, start mechanical ventilation and
them attempt to take the foreign body out E) Administer racemic epinephrine and intravenous dexamethasone to decrease
subglottic edema. Proceed with foreign body extraction after this treatment
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
60
131. A 6-year-old child is scheduled for tonsillectomy. Following induction with sevoflurane-oxygen you administer succinylcholine 1.5 mg/kg intravenously. Two minutes later it is impossible to open his mouth for intubation. What is the MOST appropriate next management plan in this situation?
A) Administer an additional intravenous dose of succinylcholine because children need higher dose
B) Cancel the surgery and monitor the child’s vitals cautiously C) Order a 12-lead EKG and draw ABG D) Determine creatine-phosphokinase levels in the blood and switch to
intravenous agents such as propofol for maintenance of anesthesia E) Administer dantrolene prophylactically and continue the surgery
132. A 30-year-old alcoholic is scheduled for emergent exploratory laparotomy for
continued abdominal bleed. He is drowsy, restless and complaining of neck pain. Physical and radiographic examinations completed so far reveal LeFort 2 and 3 fracture of maxilla, mandibular fracture, rhinorrhea and lacerated cheek. The general surgeon requests general anesthesia with complete muscle relaxation. The BEST method to secure and maintain his airway for anesthesia is:
A) Topical anesthesia of airway followed by awake oral intubation with in-line stabilization of the neck
B) Blind nasal intubation C) Awake nasal intubation using fiberoptic bronchoscope D) Rapid sequence induction followed by intubation E) Emergent tracheostomy under sedation
133. Acute respiratory distress syndrome (ARDS) is the complication of several systematic
illnesses with high morbidity and mortality. Which of the following parameters mentioned in choices A to E will show the major
pathophysiologic changes after recovery from ARDS?
A) Diffusion barrier to oxygen B) Changes in pulmonary compliance C) Changes in pulmonary capillary wedge pressure D) Changes in pulmonary shunt fraction E) Changes in oxygen dissociation curve
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
61
134. You are evaluating a 70-year-old man in ICU who had a severely stenosed aortic valve replaced with a prosthetic aortic valve. Preoperatively patient had been hemodynamically stable and his EKG showed sinus rhythm.
His present hemodynamic profile in ICU is as follows:
Heart rate 125 bpm, now in atrial fibrillation Blood pressure 75/40 mmHg Central venous pressure 18 mmHg Pulmonary capillary wedge pressure 23 mmHg Cardiac output 2.1 L/min Systematic vascular resistance 1300 dynes/sec/cm-5
What is the MOST appropriate first step to improve his hemodynamic profile?
A) Administer dopamine B) Administer dobutamine and start on nitroglycerin drip C) Cardioversion D) Administer intraaortic balloon pump E) Administer verapamil
135. An 80-year-old man with history significant for coronary artery disease is scheduled
for surgery of right eye retinal detachment. Following induction and intubation with propofol and rocuronium general anesthesia is maintained with sevoflurane and oxygen. Suddenly his blood pressure climbs to 240/110 from 120/60 mmHg and pulse decreases from 75 bpm to 40 bpm. His EKG shows run of bigeminies and trigeminies every 4 to 5 minutes. Surgeon informs you that he just instilled 10% phenylephrine into his conjunctiva to dilate his pupil. What will be the MOST appropriate action at this time?
A) Administer propanolol and lidocaine B) Administer nitroprusside C) Administer either glycopyrrolate or atropine D) Administer phentolamine E) Wait until the action of phenylephrine dissipates
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
62
136. While doing a neuroanesthesia case, adjustment of which of the following parameters will be the MOST important in regulating blood flow to ischemic cerebral tissue?
A) Mean perfusion pressure B) PaO2 C) PaCO2 D) Hyperthermia E) Cerebral metabolic rate (CMRO2)
137. Hypothermia at 33° C. will show all of the following physiologic changes EXCEPT:
A) Protection against cerebral ischemia B) Cardiac dysrhythmia and hypertension C) Increased drug metabolism and increased isoflurane MAC D) Prolongation of rocuronium action E) Impaired renal function
138. Which of the following clinical situations will be a contraindication to the use of
ketamine?
A) An 80-year-old man with a history of coronary artery disease, profoundly hypotensive, scheduled for emergency surgery for ruptured appendix
B) A 25-year-old asthmatic scheduled for emergency exploratory laparotomy after a motor vehicle accident and who is hypotensive
C) A 25-year-old with cardiac tamponade D) A 25-year-old with head trauma, hypotension and ICP of 10 E) A 16-year-old burn patient scheduled for extensive debridement of burn over
upper extremities and thorax
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
63
139. A 25-year-old heroin addict is scheduled for exploratory laparotomy after a motor vehicle accident. His vitals are: blood pressure 100/60, pulse 105 and respiration 4/min. Which of the following drugs if given to this man will produce acute withdrawal?
A) Pentazocine B) Nalbuphine C) Buprenorphine D) Naloxone E) All of the above
140. According to ACLS guidelines, during cardiopulmonary resuscitation administration of
calcium chloride is recommended during:
A) Hyperkalemia and verapamil toxicity B) Electromechanical dissociation and asystole C) Digoxin and tricyclic antidepressant toxicity D) Shock and congestive heart failure E) None of the above
141. Following repair of bilateral inguinal hernia in a 70-year-old man with a history of severe COPD, you decide to use 30 mg of ketorolac (Toradol). Which of the following statements about ketorolac is TRUE?
A) Ketorolac has little potential for renal toxicity when fluid balance is adequate B) Ketorolac analgesic effects are due to its binding to opioid receptors C) Ketorolac is excreted unchanged in urine D) Ketorolac can increase bleeding due to dose-related thrombocytopenia E) Ketorolac has analgesic effects but no antipyretic or anti-inflammatory effects
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
64
142. Midazolam (versed) is most often used pre-operatively. Compared with diazepam it is:
A) Three times more potent than diazepam B) Has longer elimination half time C) Has less clearance (ml/kg/min) D) Produces less respiratory depression E) Produces less hypotension during induction of anesthesia with opioids
143. A 75-year-old acutely ill ICU patient has serum phosphate levels of < 1 mg/dL Which of the following disorders will MOST likely be manifested in this patient?
A) Increased aspiration risk B) Increased muscle weakness C) Increased frequency of seizures D) Increased frequency of ventricular ectopic beats E) Increased GI motility and incidence of diarrhea
144. Morbidly obese patients and patients suffering from Pickwickian syndrome share
common pathophysiologic characteristics.
Which of the following characteristics will differentiate a morbidly obese patient from a patient diagnosed with Pickwickian syndrome?
A) Upper airway obstruction and carbon dioxide retention B) Decreased expiratory reserve volume C) Increased pulmonary shunt fraction D) Decreased functional residual capacity E) Increased incidence of hypertension, hypoxia and dysrhythmia
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
65
145. All of the following adverse effects can be attributed to cyclosporine toxicity EXCEPT:
A) Abnormal hepatic enzymes B) Microcytic, hypochromic anemia C) Increased serum creatinine concentration D) ST-T changes in EKG after chronic use E) Increase in nodular density of a mass present in the lung
146. Propofol is one of the most common general anesthesia inducing agents.
All of the following mechanisms contribute to propofol induced hypotension EXCEPT:
A) Systematic vasodilation B) Central vagal stimulation C) Decreased central sympathetic tone D) Resetting discharge from aortic and carotid bodies E) Myocardial depression
147. A 50-year-old man is undergoing clipping of cerebral aneurysm under general anesthesia. The maintenance anesthetics include: nitrous-oxide-oxygen-isoflurane-narcotics-relaxant. Half an hour into the procedure the neurosurgeon informs you that the brain is tense and bulging.
Patient’s vital signs and ABG are as follows: Heart rate 100 bpm Mean arterial pressure 90 mmHg PaO2 120 mmHg PaCO2 23 mmHg pH 7.5 What is the MOST appropriate immediate course of action?
A) Hyperventilate the patient to a PaCO2 of 15 mmHg B) Administer Lasix 40 mmHg intravenously C) Administer mannitol 1 g/kg intravenously D) Administer thiopental 250 mg intravenously E) Stop nitrous-oxide and volatile anesthetics and start intravenous propofol
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
66
148. A 65-year-old man is undergoing exploratory laparotomy for a mass in distal ileum. While exploring the distal ileum the patient suddenly becomes profoundly hypotensive, develops wheezing bilaterally and erythema over face and chest. What is the MOST appropriate next step to manage this patient?
A) Administer phenylephrine and steroids B) Administer vasopressin intravenously C) Administer diphenhydramine, cimetidine and fluids D) Infuse a liter of fluid E) Wait for the symptoms to resolve
K-Type Questions
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
69
149. Inhalation anesthetics suspected of causing malignant hyperthermia INCLUDE:
1) Isoflurane 2) Sevoflurane 3) Desflurane 4) Xenon
150. A 38-year-old female patient presented with hypertension, headaches, flushing and occasional episodes of sweating. Computer tomography (CT) scan of her abdomen revealed a left adrenal mass. She is scheduled for resection of the adrenal mass.
Which of the following medications would be appropriate to use perioperatively?
1) Phenoxybenzamine 2) Phentolamine 3) Prazosin 4) Phenylephrine
151. Which of the following BEST describes the response to muscle relaxants in a patient with untreated myasthenia gravis?
1) Sensitivity to non-depolarizing muscle relaxants 2) Resistant to non-depolarizing muscle relaxants 3) Resistant to depolarizing muscle relaxants 4) Sensitivity to depolarizing muscle relaxants
152. An elderly patient with Parkinson’s disease is having a right hip arthroplasty. He gives a previous history of significant postoperative nausea and vomiting (PONV) following prior surgeries.
Which of the following medications would NOT be appropriate to administer for PONV prophylaxis?
1) Droperidol 2) Ondansetron 3) Metoclopramide 4) Dexamethasone
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
70
153. A 38 year-old male with bipolar disorder is scheduled to have electroconvulsive therapy (ECT). Past medical history is significant for acute intermittent porphyria and anemia.
Which of the following are MOST appropriate to use for this patient?
1) Propofol 2) Atropine 3) Succinylcholine 4) Methohexital
154. During a radical nephrectomy procedure, you noticed that the T waves on the electrocardiogram have suddenly peaked. A blood specimen is immediately sent to the laboratory. Fifteen minutes later, the laboratory calls to the operating room because the potassium level is 6.4 mEq/L.
Which of the following are appropriate treatments to acutely reduce plasma potassium?
1) Hyperventilate 2) Administer glucose plus insulin 3) Administer sodium bicarbonate 4) Administer calcium chloride
155. Pregnancy is expected to DECREASE which of the following volume and capacities?
1) Expiratory reserve volume 2) Functional residual capacity 3) Residual volume 4) Vital capacity
156. Which of the following is associated with Complex Regional Pain Syndrome, Type I?
1) Involves a characteristic sensory nerve pattern 2) Always the result of nerve injury 3) Trophic changes are never present 4) Osteoporosis in late stages
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
71
157. Which of the following represent criteria that may be used for the diagnosis of fibromyalgia?
1) Generalized pain in 3 or more sites for 3 months or longer 2) Pain relieved by a stellate ganglion block 3) Reproducible tenderness in 11 out of 18 pre specified sites 4) Sympathetic pain relief following a phentolamine infusion
158. A 60-year-old patient is diagnosed with trigeminal neuralgia. Characteristic(s)
consistent with this diagnosis include:
1) Paroxysm of pain 2) Unilateral facial involvement 3) Trigger zones may be present 4) Involves cranial nerve VII
159. A patient with CRPS type II has just received a stellate ganglion block. Evidence that
the block has been successfully placed is confirmed by the following effect(s):
1) Myosis 2) Ptosis 3) Nasal congestion 4) Hoarseness
160. In performing a stellate ganglion block, which of the following landmark(s) should be
located?
1) Cricoid cartilage 2) Greater cornu of the hyoid bone 3) Chassaignac’s tubercle 4) C-3 transverse process
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
72
161. A patient with pancreatic cancer presents with severe abdominal pain. A celiac plexus block will be performed under fluoroscopy. Landmark(s) important to identify for performing this block include:
1) 12th ribs 2) T-12 spinous processes 3) L-1 spinous processes 4) Sacral hiatus
162. Which of the following nerve(s) require supplementation following an axillary block
of the brachial plexus?
1) Ulnar nerve 2) Intercostobrachial nerve 3) Median nerve 4) Musculocutaneous nerve
163. Epidural steroid injection has been found to be effective in all of the following
conditions EXCEPT:
1) Spondylolysis 2) Herniated disc with nerve root irritation 3) Ankylosing spondylitis 4) Spondylolisthesis
164. A patient has been diagnosed with Complex Regional Pain Syndrome (CRPS) Type II,
of hers left upper extremity. Which of the following medications are appropriate in the treatment of CRPS, Type II?
1) Clonidine 2) Amitriptyline 3) Gabapentin 4) Morphine
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
73
165. A patient is to undergo surgery for internal fixation of his right ankle fracture. He does not wish to have general anesthesia but agrees to a spinal anesthetic.
Which of the following complications are possible due to a spinal anesthetic?
1) Hypotension 2) Hypothermia 3) Bradycardia 4) Cardiac arrest
166. A 44-year-old diabetic female is to have an amputation of her left foot because of
vascular insufficiency. She has agreed to a spinal anesthetic.
Which of the following factor(s) have the MOST influence on the spread (height of block) of the local anesthetic in the subarachnoid space?
1) Patient’s height 2) Volume injected 3) Local anesthetic concentration 4) Baricity of local anesthetic
167. It is 2 PM in the afternoon, and a patient is scheduled to undergo a surgical
procedure and you wish to perform a spinal anesthetic. In order for the patient to leave the recovery room by 5:30 PM (the closing time of the surgical center), the spinal must have receded enough to discharge the patient.
Which of the following factor(s) influence the duration of a spinal anesthetic?
1) Used of adrenergic agonist 2) Type of local anesthetic 3) Drug dose 4) Block height
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
74
168. Perioperative factor(s) known to INCREASE the risk of postoperative nausea and vomiting is/are:
1) Sex 2) Age 3) Use of opioids 4) Tobacco use
169. A 44-year-old female patient is scheduled for hysterectomy for fibroleiomyoma. She
has a previous history of receiving anesthesia and experiencing postoperative nausea and vomiting (PONV).
Which of the following medications would be appropriated for prophylaxis against PONV?
1) Droperidol 2) Dolasetron 3) Dexamethasone 4) Ondansetron
170. The reversal of a neuromuscular blockade caused by vecuronium is dependent upon:
1) Gradual metabolism 2) Redistribution 3) Administration of cholinesterase inhibitors 4) Significant metabolism by pseudocholinesterase
171. Interactions between the neuromuscular blocking agents will have the following effects:
1) The combination of Rocuronium and Cis-atracurium are synergistic 2) Pre curarizing dose of D-Tubocurarine will shorten the duration of action of
succinylcholine 3) The potency of Rocuronium is enhanced when administered after
succinylcholine 4) The duration of action of succinylcholine is shorter when administered after
Pancuronium
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
75
172. When monitoring the neuromuscular blockade:
1) The response of the orbicularis oculi over the eyelid is similar to that of the adductor pollicis
2) The response of the eyebrow (corrugator supercilii) is similar to that of the laryngeal adductors
3) The onset of neuromuscular blockade occurs earlier at the diaphragm 4) The dose response curve of the neuromuscular blocking drugs for the
diaphragm is shifted to the left 173. During the recovery of neuromuscular blockade with rocuronium, the TOF ratio (train
of four) at the adductor pollicis is 0.7. At this point of recovery:
1) Protection of the airway against regurgitation can be impaired 2) Most patients complain of visual symptoms 3) In the majority of patients, sustained bite is not present 4) Grip strength can be decreased
174. When monitoring the neuromuscular blockade:
1) TOF (train of four) stimulation can be repeated every 5 seconds 2) The post tetanic twitch count should not be repeated more often than every
5 minutes 3) TOF is more painful than the tetanic stimulation at 50 Hz for 5 seconds 4) The most sensitive test for detecting residual paralysis is the ability to
maintain sustained contractions to 100Hz of tetanus for 5 seconds 175. A patient with hemiplegia:
1) May develop cardiac arrest following the administration of a depolarizing muscle relaxant
2) Shows increased sensitivity to nondepolarizing muscle relaxants 3) Has a less intense block on the affected limb 4) Shows faster recovery of the neuromuscular blockade on the unaffected side
than the affected side
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
76
176. The Mapleson D breathing system:
1) Is functionally similar to Mapleson E and F systems 2) Has a T piece near the machine end 3) Requires high fresh gas flows to prevent rebreathing of carbon dioxide 4) Is the most efficient of the Mapleson systems during spontaneous ventilation
177. Fail-safe valve:
1) Is located downstream from the nitrous oxide supply source 2) Interrupts the supply of nitrous oxide if the oxygen flow decreases 3) Is located upstream of the flow control valves 4) Prevents hypoxic gas delivery to the patient
178. Which of the following is/are TRUE in relation to the allergic reactions occurring during anesthesia?
1) Allergic reactions to local anesthetics remain uncommon despite their
frequent use 2) Muscle relaxants are the most frequently involved drugs 3) Anaphylactoid reactions are considered to activate only basophils 4) Increased concentration of tryptase (greater than 25 µg/L) suggest an
anaphylactic reaction 179. In order to optimize circle system design, the following arrangement of the major
components is/are preferred:
1) Unidirectional valves should be close to the patient 2) The fresh gas inlet should be placed between the absorber and the
expiratory valve 3) The pressure relief valve should be placed immediately before the absorber 4) The breathing bag should be located in the inspiratory limb
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
77
180. Causes of increased peak inspiratory pressure (PIP) with little change in plateau pressure (PP) include:
1) Bronchospasm 2) Pulmonary edema 3) Increased inspiratory gas flow rate 4) Increased tidal volume
181. The causes of acute onset, inspiratory stridor in a POSTOPERATIVE patient
include:
1) Laryngospasm 2) Laryngeal edema 3) Foreign body aspiration 4) Bilateral paralysis of superior laryngeal nerve
182. During the monitoring of direct arterial blood pressure:
1) Incidence of radial artery thrombosis can be minimized by avoiding tapered catheters
2) Arterial sampling is an important source of bacterial contamination of transducer systems
3) Cerebral air embolism is a possible complication 4) Systolic pressure reading at the radial artery exceeds that of the aortic root
183. Evoked potentials:
1) Are used intraoperatively to evaluate the functional integrity of sensory and motor pathways
2) Of brain stem origin (BAEP) are less vulnerable to anesthetic agents than the evoked potentials of cortical origin (cortical component of SSEP or VEP).
3) Are minimally affected by opioids 4) Are minimally affected by N2O at concentrations of less than 50%
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
78
184. Remifentanil hydrochloride:
1) Is a synthetic opioid 2) Is a selective µ-opioid receptor agonist 3) Has an elimination half-life of about 9 minutes 4) Is rapidly metabolized by pseudocholinesterases
185. Morphine:
1) Does not suppress myocardial contractility at clinical doses 2) When administered orally, morphine-6-glucuronide (M6G) is the primary
active compound 3) Has a bioavailability of <30% when administered orally 4) Releases less histamine when pre-treated with naloxone
186. Opioid induced muscle rigidity:
1) Is due to a direct action on muscle fibers 2) Can be decreased or prevented by pretreatment with muscle relaxants 3) Is associated with increase in creatinine kinase 4) Is mu receptor mediated
187. Morphine-6-glucuronide (M6G):
1) Is a more potent mu receptor agonist than morphine 2) Is the major metabolite of morphine 3) Has duration of action similar to that of morphine 4) Possesses a little or no analgesic activity
188. Ondansetron:
1) Is a selective antagonist at serotonin (5-HT3) receptors 2) May cause prolongation of the QT-interval 3) Is effective in the treatment of perioperative nausea and vomiting 4) Increases the lower esophageal sphincter tone
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
79
189. Dexmedetomidine:
1) Is a highly selective alpha-2 –adrenergic agonist 2) Frequently causes dry mouth 3) Causes bradycardia 4) Increases the requirement of volatile anesthetics during general anesthesia
190. Flumazenil:
1) Has minimal intrinsic activity 2) When used to reverse diazepam, the potential for re-sedation exists 3) Can precipitate withdrawal symptoms in patients physically dependent on
benzodiazepines 4) Irreversibly binds to the benzodiazepine receptors
191. Hydroxyethyl Starch:
1) Is a synthetic colloid solution 2) Interferes with cross-matching of blood due to rouleaux formation 3) Is degraded by amylase 4) Often causes allergic reactions
192. Respiratory effects of potent volatile anesthetic agents include:
1) High concentration of volatile anesthetics may virtually obliterate the hypercarbia-induced increase in ventilatory drive
2) All volatile anesthetics decrease tidal volume 3) Most volatile agents depress the ventilatory response to hypoxia at
subanesthetic concentrations. 4) Isoflurane and sevoflurane can reverse bronchospasm with equal efficacy at
1.1 MAC
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
80
193. During general anesthesia with nitrous oxide:
1) Megaloblastic bone marrow changes are seen in healthy patients after 2 hours of exposure
2) Causes subacute combined degeneration of the spinal cord only after several months of daily exposure
3) Causes reversible inactivation of the enzyme methionine synthase 4) Causes very low methionine synthetase activity after a few hours of
anesthesia 194. Which of the following is/are effect(s) of Nitrous Oxide?
1) Decreased uterine contractility 2) Decreased pulmonary vascular resistance 3) Decreased sympathetic nervous system activity 4) Expansion of air filled spaces
195. Factors that influence the magnitude of carbon monoxide production from volatile
anesthetics include:
1) Dryness of the carbon dioxide absorbant 2) High temperature of the carbon dioxide absorbant 3) Prolonged high fresh gas flows 4) Exposure to soda lime rather than Baralyme
196. Sevoflurane:
1) Causes formation of organic and inorganic fluoride metabolites 2) Results in formation of trifluoroacetylated liver proteins 3) Produces peak plasma fluoride concentrations that are higher than after
comparable doses of enflurane 4) Produces higher carbon monoxide concentration than desflurane on exposure
to soda lime
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
81
197. Supine hypotension syndrome in pregnancy:
1) Is primarily a result of inferior vena caval occlusion 2) May reduce the blood flow to the uterus by as much as 45% 3) Causes approximately 1 in 10 pregnant women to become symptomatic 4) Is relieved in the Trendelenburg position
198. Physiological changes of pregnancy include:
1) Elevation of the central venous pressure 2) Decrease in the colloid oncotic pressure 3) Physiological anemia secondary to decrease in red blood cell mass 4) Threefold elevation of alkaline phosphatase
199. Transient neurological syndrome (TNS):
1) Characterized by back pain with sensory or motor deficit 2) Resolves spontaneously within several days 3) Has never been reported with bupivacaine 4) Has higher incidence with lidocaine spinal and lithotomy position
200. The following recommendations is/ are TRUE regarding neuraxial anesthesia in the
presence of antiplatelet and anticoagulation medications:
1) Clopidogrel should be discontinued for 7 days before a neuraxial anesthesia 2) Aspirin may be safely used in patients having epidural or spinal injections 3) Subcutaneous heparin does not appear to increase the risk of spinal
hematoma 4) Post surgical prophylactic dose of low molecular weight heparin (LMWH) may
be started 2-4 hours after removal of epidural catheter.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
82
201. Smallpox:
1) May be difficult to differentiate from chickenpox during the first 2-3 days 2) May cause death due to toxemia and overwhelming pneumonia 3) Vaccine consists of live attenuated vaccinia virus 4) Vaccine offers lifelong immunity
202. Dolasetron Mesylate:
1) May cause prolongation of QT interval in the ECG 2) Require dose adjustment in patients with hepatic or renal impairment 3) Has a major metabolite with potent serotonin (5HT3) receptor agonist
activity 4) Has an elimination half-life of 10 hours
203. Ephedrine:
1) Is an indirectly acting sympathomimetic amine 2) Has four stereoisomers 3) Is superior to other vasopressors in preserving uteroplacental blood flow 4) Has an important centrally mediated sympathetic action
204. Transdermal fentanyl preparation (Fentanyl patch):
1) Provides extended period of slow drug administration 2) In febrile patients may increase fentanyl absorption 3) Achieves therapeutic levels within 6-8 hours 4) Stops the uptake of fentanyl immediately after removal of the patch
205. Treatment of Aspiration Pneumonitis include:
1) Supplemental oxygen 2) Positive end-expiratory pressure (PEEP) 3) Inhalation of beta-2-agonists 4) Lavage with large volumes of saline administered through the endotracheal
tube
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
83
206. Functional residual capacity (FRC):
1) Is the volume of gas in the lung at the end of a vital capacity breathe 2) Equals the residual volume plus the inspiratory reserve volume 3) Is measured by simple spirometry 4) Can be measured using body plethysmography
207. Closing capacity (CC):
1) Is a sensitive test of early small airway disease 2) If lies below the normal tidal ventilation, atelectasis will occur 3) Is measured by the use of a tracer gas such as Xenon-133 (Xe133) 4) Is decreased in obesity
208. Functional residual capacity (FRC):
1) Decreases significantly with the induction of general anesthesia 2) Reduction correlates with an increase in alveolar-arterial PO2 gradient during
anesthesia (A-a gradient) 3) Remains decreased into the postoperative period 4) Always decreases progressively during the course of anesthesia
209. Causes of increase in the volume of Zone 1 of pulmonary circulation include:
1) Deliberate hypotension 2) Positive end expiratory pressure (PEEP) 3) Pulmonary embolism 4) Increase in airway pressure
210. Moderate hypercapnia will cause:
1) Increased QT interval 2) Rise in plasma potassium 3) Increased myocardial oxygen demand 4) Decreased pulmonary vascular resistant
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
84
211. In superior vena cava syndrome:
1) Malignancy is the underlying cause in 90% cases 2) Dyspnea and headache are the most common symptoms 3) Patient may present with changes in mental status 4) Changes in voice or stridor may occur
212. P-50 (P50):
1) Describes the position of the oxy-hemoglobin curve 2) When lower, may require higher than normal tissue perfusion to produce the
normal amount of oxygen unloading 3) Is lower in carbon monoxide poisoning 4) Is lower in methemoglobinemia
213. Bainbridge reflex:
1) Is stimulated by increases in intravascular volume 2) Causes increased heart rate 3) Sends afferent impulses through vagus nerve 4) Has its receptors within the right atrial wall
214. Baroreceptor reflex:
1) Responds to changes in blood pressure via stretch receptors present in the carotid sinus and aortic arch
2) Sends impulses along the afferent limbs of glossopharyngeal and vagus nerves
3) Typically begins to respond at pressures in excess of 170 mmHg 4) Response is increased contractility, heart rate and vascular tone
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
85
215. Coronary blood flow:
1) Is principally driven by mean arterial pressure 2) Through the left side is maximal during peak systole 3) Exhibits some degree of autoregulation 4) Through the right side is maximal during early diastole
216. Which of the following statement(s) about the types of pacemakers and their
functions is/are TRUE?
1) A VVIR pacemaker senses electrical activity only in the ventricle 2) A VDD pace maker can pace and sense both the atrium and the ventricle 3) An AOO pacemaker is a fixed rate pace maker 4) When an AAI pacemaker senses an intrinsic electrical beat in the atrium, it
triggers the generator to fire 217. A 67-year-old man had a permanent endocardial VVI pacemaker placed 2 years ago
for complete heart block. He has a history of insulin dependent diabetes mellitus and angina on exertion. On the ECG tracing, the pacemaker spike appears at the proper time, but is not followed by the expected QRS complex.
This failure to capture may be caused by:
1) Battery failure 2) Hyperkalemia 3) Myocardial ischemia 4) Severe hyperglycemia
218. Mild hypothermia (≈ 34o C.):
1) Causes platelet dysfunction 2) Directly impairs enzymes of the coagulation cascade 3) Impairs immune function 4) Decreases wound oxygen delivery
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
86
219. Postanesthetic shivering:
1) Increases oxygen consumption about 100% 2) Increases intraocular pressure 3) Can be treated by skin surface warming 4) Increases intracranial pressure
220. TRUE statements concerning perioperative temperature control include:
1) Operating room temperature is the most crucial factor influencing heat loss 2) One cotton blanket placed on the patient reduces heat loss by about 30% 3) The most effective perianesthetic warming system is forced air warming
blanket 4) Circulating water mattresses does not cause burns if the water temperature
is kept under 40o C. 221. Acute normovolemic hemodilution (ANH):
1) Is employed to reduce the need for allogenic red blood cells 2) Is contraindicated in the presence of malignancy 3) May improve tissue perfusion 4) Is contraindicated in the presence of wound infection
222. Potential complications associated with intraoperative use of the cell saver device
include:
1) Air and fat embolism 2) Rh isoimmunization during cesarean deliveries 3) Renal dysfunction secondary to lysis of red blood cells 4) Disseminated intravascular coagulation
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
87
223. The following statements regarding the maternal mortality is/are TRUE:
1) Hemorrhage accounts for more than 25% of maternal deaths 2) In the United States, maternal deaths due to anesthesia related
complications have decreased within the last twenty years 3) Maternal case-fatality risk ratio for general anesthesia has shown to be 16
times that of regional anesthesia after 1985 4) The leading cause of maternal mortality is airway problems
224. The ligamentum flavum:
1) Developmentally, is a paired structure 2) May have midline gaps due to lack of fusion in the mid-line 3) Is thinnest at the cervical and high thoracic levels 4) Is composed of collagenous fibers
225. TRUE statements concerning the uterine blood flow at term include:
1) 20% of the uterine blood flow supplies the intervillous space 2) 80% of the uterine blood flow supplies the uterine myometrium 3) Uterine vessels are not sensitive to alpha-adrenergic agonists 4) Total uterine blood flow approaches 800 ml/min
226. Inhaled nitric oxide:
1) Acts by increasing cyclic guanosine monophosphate 2) Is a systemic and pulmonary vasodilator 3) May be potentiated by Sildenafil, phosphodiesterase-5 inhibitor 4) Causes systemic hypotension
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
88
227. Potentiation of nondepolarizing neuromuscular blockade occurs in the presence of:
1) Metabolic acidosis 2) Respiratory acidosis 3) Decreased extracellular concentration of potassium 4) Cephalosporins
228. Factors that interfere with adequate reversal of nondepolarizing blockade include:
1) Respiratory acidosis (PaCO2 greater than 50 mmHg) 2) Hypothermia 3) Low extracellular potassium concentration 4) Magnesium sulfate
229. When compared with neostigmine, edrophonium:
1) Has less muscarinic effects 2) Has a quicker onset of action 3) Has fewer side effects 4) Is not broken down by acetylcholinesterase
230. In a myasthenia gravis patient on pyridostigmine therapy:
1) The sensitivity to non depolarizers may be diminished 2) The response to succinylcholine may be lengthened 3) The reversal of residual block at the end of the case may be ineffective 4) Often surgical relaxation can be provided using a potent inhaled anesthetic
only
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
89
231. The following statement(s) is/are TRUE concerning the influence of severe renal failure on the pharmacology of nondepolarizing muscle relaxants:
1) The duration of mivacurium may be lengthened due to decrease in the
plasma cholinesterase activity 2) The elimination half life of laudanosine is unchanged 3) The duration of action of atracurium is not affected by renal failure 4) The volume of distribution of rocuronium is decreased in renal failure
232. Magnesium sulphate enhances the neuromuscular blocking properties of muscle
relaxants by:
1) Decreasing the amount of acetylcholine (Ach) released from the motor nerve terminal
2) Increasing the depolarizing action of the Ach on the postjunctional membrane
3) Decreasing the excitability of the muscle fiber itself 4) Increasing the amplitude of the end-plate potential
233. The following drugs enhance the effect of nondepolarizing muscle relaxants:
1) Local anesthetics 2) Phenytoin 3) Dantrolene 4) Carbamazepine
234. Action(s) of local anesthetics in the nerve membrane include:
1) Disruption of sodium channel activation process 2) Alteration in the threshold potential 3) Blockade of the ion-conducting pores 4) Alteration in the resting membrane potential
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
90
235. The following statement(s) about amide and ester local anesthetics is/are TRUE:
1) Ester local anesthetics are relatively unstable in solution 2) Amide compounds undergo enzymatic degradation in the liver 3) Reports of allergic reactions to amide compounds are extremely rare 4) Amide local anesthetics are extremely stable in solution
236. The risk of developing local anesthetic toxicity is influenced by:
1) Rate of injection 2) Hypercarbia 3) Metabolic acidosis 4) Site of injection
237. Cardiovascular effects of induction dose of intravenous thiopental include:
1) Vasodilatation 2) Decreased myocardial contractility more than that of volatile anesthetics 3) Hypotension which is greater in hypertensive patient than in normotensive
patients 4) Increased heart rate more than after equivalent dose of methohexital
238. Which of the following drugs has the potential to occlude the intravenous line when
co-administered with thiopental?
1) Vecuronium 2) Atracurium 3) Sufentanil 4) Midazolam
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
91
239. Esmolol:
1) Is a nonselective beta-receptor antagonist 2) May cause hypotension 3) Rapidly eliminated by plasma pseudocholinesterases 4) After discontinuation most drug effects are eliminated within 5 minutes
240. Signs of nitroprusside toxicity include:
1) Tachyphylaxis 2) Decreased mixed venous PO2 3) Metabolic acidosis 4) Cyanosis
241. In a cardiac transplanted patient:
1) Resting heart rate is low 2) Reflex bradycardic response is absent after carotid sinus massage 3) Cardiac output is increased primarily by increased heart rate 4) Response to laryngoscopy may be delayed or blunted
242. The following pharmacodynamic alterations may be seen in a cardiac transplanted
patient:
1) No change in heart rate with administration of atropine and glycopyrrolate 2) Increased response to epinephrine and norepinephrine 3) Absent reflex bradycardia or tachycardia in response to changes in systemic
arterial blood pressure 4) Reduced response to alpha-adrenergic agents
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
92
243. Angiotensin II:
1) Is a direct vasoconstrictor 2) Enhances the pre junctional release of norepinephrine from the adrenergic
nerve ending 3) Increases efferent sympathetic nerve activity 4) Stimulates the secretion of aldosterone
244. Patients with high spinal cord transaction may develop:
1) Bradycardia with changes in position 2) Hyperthermia easily 3) Hypothermia easily 4) Decreased response to exogenous vasopressors
245. The following statements is/are TRUE regarding the patients requiring perioperative
corticoid supplementation:
1) Inadequate corticosteroid coverage can cause death 2) Administration of supraphysiologic doses of steroid for a short time
perioperatively causes no discernible complications. 3) Even topical application of steroid can suppress normal adrenal response for
as long as 9-12 months. 4) Plasma cortisol concentration of more than 25 µg/ml, measured during acute
stress, indicates normal pituitary–adrenal responsiveness 246. Etomidate:
1) Is an imidazole sedative-hypnotic 2) Causes compromised adrenal reserves for at least 24 hours after a single
induction dose 3) Causes minimal cardiovascular depression 4) Inhibits two essential adrenocortical
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
93
247. Antagonist(s) used for prophylaxis and treatment of postoperative nausea and vomiting are specific for which chemoreceptor trigger zone receptor(s)?
1) Serotonin 2) Cholinergic 3) Dopamine 4) Histamine
248. Regarding thermoregulation, afferent signals from peripheral receptors that sense temperature travel primarily through which nerve fiber type(s)?
1) A - alpha fiber 2) A - delta fiber 3) A - gamma fiber 4) Unmyelinated C - fiber
249. Which of the following pharmacological factors favor the transfer of drugs across the placenta into the fetal circulation?
1) Low molecular weight 2) High degree of ionization 3) Low protein binding 4) Low lipid solubility
250. A child presents to the emergency room in respiratory distress and a history of dysphagia and drooling. You are called to the ER for possible intubation and securing of the airway. A diagnosis of epiglottitis is suspected. What other clinical characteristics are consistent with epiglottitis?
1) Insidious onset of symptoms 2) Low grade fever 3) Croupy (barking) cough 4) Usually affects children ages 2 to 6 years
Answers
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
97
1. E Umbilical cord compression High doses of bupivacaine can produce peripheral vasodilation, which in turn produce
peripheral venous pooling. This drops maternal blood pressure producing an acute
decrease in umbilical blood flow. Loss of fetal beat-to-beat variability results from umbilical
cord compression or severe hypotension leading to fetal hypoxemia. The treatment include
administration of supplemental oxygen to the mother, altering maternal position to the left
side in order to relieve pressure from gravid uterus on great vessels and correcting
maternal hypotension.
1. Longnecker DE, Tinker JH, Morgan GE (eds.) Principles and Practice of Anesthesiology. 2nd edition. Mosby Baltimore MD. 1998:1997. 2. A Inform the patient and take no action The presence of a small piece of epidural catheter in the epidural space is less likely to
pose any problem. Currently, the standard of care for retention of a segment of epidural
catheter in epidural space is to leave the segment in the space, inform the patient of
mishap and follow up the patient with neurological examination. However, if a continuous
spinal anesthesia is used and catheter tip gets broken or separated in the subarachnoid
space, patient should be followed for neurological symptoms and neurosurgical consult be
sought for possible retrieval of the broken segment. Use of antibiotics is not advisable.
1. Tio To, Macmurdo SD, McKenzie R: Mishap with an epidural catheter. Anesthesiology 1979;50:260-262. 3. B Hypertension The dose required to achieve adequate epidural anesthesia can cause serious side effects if
injected into the subarachnoid space or into a blood vessel, therefore a test dose is often
administered before injection. The test dose often consists of a local anesthetic and
epinephrine. The objective of test dose is to rule out intravascular or subarachnoid
injection. During administration of a test dose, 15 micrograms of epinephrine is
administered which should increase the heart rate by 20% within 60 seconds if the catheter
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
98
is intravascular in the epidural vein. This same test dose should produce a sensory block if
it is in the subarachnoid space. Of the choices given, only choice B is the most plausible.
This response (hypertension) will be much more marked if the patient had been on beta-
blocker due to unopposed alpha effects.
1. Longnecker DE, Tinker JH, Morgan GE (eds). Principles and Practice of Anesthesiology. 2nd edition. Mosby Baltimore MD. 1998:1401. 4. D Intercostal Serum concentration depends upon the vascularity at the site of injection. The more
vascularized the tissue, the greater the systemic absorption of the local anesthetic and the
increased potential for toxicity. In descending order, the rate of developing serum
concentration of local anesthetics from highest to lowest is as follows: intravenous >
tracheal > intercostal > caudal > paracervical > epidural > brachial > local nerves >
subcutaneous.
1. Morgan GE, Mikhail MS. Clinical Anesthesiology. 2nd edition Appleton and Lange CT. 2002:235. 5. A Fentanyl when combined with epidural bupivacaine will decrease the concentration of the later for satisfactory analgesia Epidural opioids combined with local anesthetics are increasingly used for optimal
management of intraoperative and postoperative analgesia. Local anesthetic when
combined with opioids reduces the local anesthetic dose while equaling or sometimes
improving analgesia. Opioids block the pain transmission by binding at presynaptic and
postsynaptic receptor sites in the spinal cord. Inclusion of opioids can produce side effects
such as respiratory depression, nausea, pruritus and urinary retention. Of the choices given
one can argue that choice D is correct as well because the addition of epinephrine would
decrease the rate of vascular absorption therefore decreasing the systematic opioid blood
concentration and further improving the depth and duration of analgesia. However, this
combination may not significantly prolong the duration of fentanyl or sufentanil analgesia,
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
99
since it is lipid solubility that determines the onset of action of epidural placed opioids. Both
fentanyl and sufentanil are highly lipid soluble opioids.
1. Longnecker DE, Tinker JH, Morgan GE (eds). Principles and Practice of Anesthesiology. 2nd edition. Mosby. Baltimore MD. 1998:1400. 6. E Bupivacaine blocks cardiac sodium channels for prolonged period Cardiac toxicity varies for each local anesthetic with bupivacaine being more cardiotoxic
than lidocaine. Intravenous injection of bupivacaine may results in hypotension, ventricular
tachycardia, fibrillation, and AV heart block. Bupivacaine binds to sodium channel tightly
and dissociates slowly, leading to its prolonged and exaggerated effects. It depresses the
rapid phase of depolarization in Purkinje fibers and ventricular muscles. Bupivacaine does
not enhance the Na-K exchange in the myocardium or increase the sensitivity of
myocardium adrenergic receptors to catecholamines. It has no effect on myocardial Ca-
channels and is highly lipid soluble. After accidental IV injection, the protein binding sites
(alpha1-acid glycoprotein and albumin) are quickly saturated, leaving a significant mass of
unbound drug available for diffusion into the conducting tissue of the heart. Cardiotoxic
plasma concentrations of bupivacaine are 8 to 10 µg/ml.
1. Stoelting RK, Miller RD. Basics of Anesthesia. 4th edition. Churchill Livingstone. New York NY. 2000:85-6. 7. A Inject 3 ml of local anesthetics lateral to biceps tendon at the flexion of the crease For an incomplete brachial plexus block that spares radial nerve distribution, radial nerve
block is performed as a supplement. The radial nerve is a terminal branch of posterior cord
of brachial plexus and gives rise to the lateral cutaneous nerve of the arm and posterior
cutaneous nerve of the forearm (both sensory). At the lateral epicondyle the radial nerve
branches into a superficial branch (which innervates the radial aspect of wrist and
dorsolateral aspect of 3 1/2 digits) and a deep branch (which innervates the extensor
group of forearm muscles). The supplemental block is performed by injecting 3 to 5 ml of
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
100
local anesthetics at the lateral aspect of biceps tendon at the flexion crease. The other
nerve, which often fails to be blocked, is the musculocutaneous nerve. This nerve is
blocked by injecting 5-8 ml of local anesthetics into the belly of coracobrachialis muscle.
1. Morgan GE, Mikhail MS. Clinical Anesthesiology. 3rd edition. McGraw Hill, New York NY. 2002: 292 – 293. 8. E Recurrent laryngeal nerve block An interscalene block is performed for procedures involving the upper extremity, including
the shoulder. The interscalene block is performed by injecting 40 ml of local anesthetics
between anterior and middle scalene muscles at the level of cricoid cartilage. Complications
of interscalene block include: recurrent laryngeal nerve block which this patient has,
injection into the vertebral artery (leading to seizure), epidural and subarachnoid injections,
pneumothorax, and stellate ganglion block leading to Horner’s syndrome (miosis, ptosis,
anhydrosis, nasal congestion, vasodilation and increased skin temperature). Besides these,
infection, hematoma and nerve injury may also occur.
1. Morgan GE, Mikhail MS. Clinical Anesthesia. 3rd edition, McGraw Hill, New York NY. 2002: 288-289. 9. B Most intense analgesia with epidural administration Urinary retention after neuroaxial block with opioids is more common than after
intravenous administration. This is not dose dependent or related to systematic absorption
but rather due to interaction of opioids with receptors located in the sacral spinal cord.
Keep in mind that epidural administration of morphine produces more intense analgesia,
longer duration of action and a greater incidence of pruritus. Analgesia that follows epidural
placement of morphine reflects diffusion across the dura to gain access to mu opioid
receptors on the spinal cord as well systematic absorption into the circulation. Since
morphine is poorly lipid soluble it has slower onset of analgesia but longer duration of
action. In contrast, analgesia by epidural administration of highly lipid soluble opioids
(fentanyl, sufentanil) is primarily a reflection of systematic absorption.
1. Stoelting RK. Pharmacology and Physiology of Anesthesia. 3rd edition. Lippincott-Raven. New York NY. 1999: 79 – 83.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
101
10. C Faster onset of analgesia Fentanyl is a more lipid soluble opioid when compared to morphine. Fentanyl’s greater
potency and more rapid onset of action compared with morphine, reflects this higher lipid
solubility which facilitated its passage across the blood-brain barrier. The short duration of
action of fentanyl reflects its rapid redistribution to inactive tissue sites such as fat and
skeletal muscles. In contrast, morphine is poorly lipid soluble, is absorbed slowly to reach
its site of action in the CNS. Other reasons for poor penetration of morphine into the CNS
(< 0.1%) include: high degree of ionization and rapid conjugation with glucuronic acid in
liver and kidney. Once inside CNS it diffuses back into circulation slowly. This increases
the duration of action significantly when compared to fentanyl. There is no difference in
the sensitivity of various opioids to naloxone.
1. Stoelting, RK. Pharmacology and Physiology of Anesthesia. 3rd edition. Lippincott-Raven. New York NY. 1999: 92-93. 11. E Subarachnoid injection This question emphasizes the complications of interscalene block, which include:
subarachnoid (as in this case) or epidural injections, nerve blocks (phrenic and recurrent
laryngeal nerves), and stellate ganglion block (ptosis, anhydrosis, miosis, enophthalmos,
nasal congestion, vasodilation and increased skin temperature). Absorption into systematic
circulation due to proximity of vertebral artery can result in CNS toxicity (convulsions).
Besides, because of close proximity of cervical neural foramina, inadvertent injection into
epidural and subarachnoid space is not uncommon. This may produce high epidural or high
spinal anesthesia leading to apnea. Other common complications of interscalene block are:
phrenic and/or laryngeal nerves block with associated hemiparesis of the diaphragm and
laryngeal muscles. The risk of pneumothorax is remote.
1. Morgan GE, Mikhail MS, Murray MJ. Clinical Anesthesia. 3rd edition. McGraw-Hill New York NY. 2002:289.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
102
12. B Enhance peristalsis with diarrhea and manifestation of hypotension Celiac plexus is formed by the union of the greater (T5-T10), lesser (T10-T11), and least
(T12) splanchnic nerves and the celiac branch of right vagus. It contains both sympathetic
and parasympathetic fibers. This extensive network of ganglia and nerves is located at the
level of first lumbar vertebra in the retroperitoneal space along the aorta. Fibers from this
ganglion carry pain sensation from many of the intraperitoneal organs such as the pancreas
and liver. Celiac plexus block is a sympathetic block, commonly applied for the relief of pain
from malignancy of the pancreas, liver, or other upper abdominal organs. A successful
block is indicated by disappearance of pain in cancer patients or postural hypotension and
diarrhea in normal patients. The later symptoms are due to the preponderance of
parasympathetic response. Choice D is more of a function of sacral plexus. Celiac plexus
does not supply somatic fibers to pancreas.
1. Wildsmith JAW, Armitage EN, McClure JH. Principles and Practice of Regional Anesthesia. 3rd edition. Churchill Livingstone. 2003:301. 13. D Wait 20 minutes and then deflate and re-inflate immediately, and finally
deflate after 1 minute For short procedures involving extremities Bier block can be performed which is the
injection of local anesthetics (50 ml 0.5% lidocaine) into the venous system below an
occluding tourniquet. If surgery is completed in less than 20 minutes, the tourniquet is left
inflated to avoid sudden absorption of local anesthetics into the systematic circulation
which can produce cardiac and CNS toxicity. If the surgery is completed between 20 and 40
minutes, the cuff can be deflated and reinflated immediately, thus releasing small amount
of local anesthetics into the systematic circulation each time. Finally after 1 minute it is
deflated completely. However, one can deflate the cuff as a single maneuver after 40
minutes because most of the local anesthetics has been metabolized and chances of local
anesthetic toxicity is insignificant.
1. Stoelting RK, Miller RD. Basics of Anesthesia. 4th edition. Churchill Livingstone. 2000: 193-195.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
103
14. D PDPH is less frequent if the needle bevel is parallel to the direction of dural fibers Post-dural puncture headache (PDPH) is most often seen following an epidural block due to
wet tap. It is believed due to loss of CSF through the meningeal needle hole resulting in
decreased buoyant support for the brain and increased tension on meningeal vessels and
nerves. The headache is frontal or occipital and postural in nature which worsens in the
sitting or standing position. The headache may be associated with diplopia, tinnitus and
decreased hearing acuity. Non-cutting needles (Greene, Whitcare and Sprott) have lower
incidence of headache than the cutting needles (Quincke, Pitkin). There is lower incidence
of PDPH if the needle bevel is parallel to the meningeal fibers (that is the bevel points in
the lateral direction if the patient is in the sitting position). There is higher incidence of
PDPH in young, pregnant females and with the use of lower gauge needles. Treatment
include: bedrest, analgesics (Tylenol double strength), oral or intravenous hydration, and
administration of caffeine sodium benzoate (500 mg iv) and blood patch. Although,
controversial, it is likely that a prophylactic epidural blood patch may be effective in
preventing postdural puncture headache in patient with accidental dural puncture.
1. Stoelting RK, Miller RD. Basics of Anesthesia. 4th edition. Churchill Livingstone. 2000: 177. 15. D Musculocutaneous nerve The brachial plexus is formed from the anterior rami of C5 - T1. There are three
approaches (interscalene, supraclavicular and axillary blocks) to block brachial plexus based
on anatomic locations where local anesthetic solutions are placed. The anesthesia
produced with each approach is significantly different in terms of its usefulness. For
example in axillary approach of brachial plexus block, musculocutaneous and medial
antebrachial cutaneous nerves may be missed, thus this approach may produce inadequate
anesthesia of forearm. The Musculocutaneous nerve (C5-C7) leaves the axillary sheath
proximal to the point of injection into the axilla. Its principal sensory branch is, lateral
cutaneous nerve of the forearm supplying thenar eminence and motor branch to upper arm
flexors. The musculocutaneous nerve can be blocked by injecting 10 ml of local
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
104
anesthetics 5 cm proximal to the elbow crease between biceps and brachialis muscles into
the substance of coracobrachialis muscle.
1. Stoelting RK, Miller RD. Basics of Anesthesia. 4th edition. Churchill Livingstone. 2000:189. 16. A Sural nerve Sciatic nerve is the main nerve of the lower extremity which divides into anterior and
posterior tibial nerves near popliteal fossa. Posterior tibial nerve supplies the sole of the
foot and is blocked by injecting 5 ml of local anesthetic posterior to medial malleolus,
behind posterior tibial artery. Injecting 5 ml of local anesthetics anterior to the medial
malleolus can block the saphenous nerve, a branch of femoral nerve which innervates a
strip along the medial aspect of foot. Sural nerve innervates the lateral aspect of the foot
and little toe. It is blocked by injecting 5 ml of local anesthetic solution between the lateral
malleolus and calcaneus. Deep peroneal nerve supplies the dorsum of the foot, lies
between the anterior tibial artery and the tendon of the anterior tibial muscle and
innervates the skin between the first and second toes and the short extensors of the toes.
It is blocked by injecting 5 ml of local anesthetics anterior to medial malleolus lateral to
anterior tibial artery. Injecting 5 ml of local anesthetics as a subcutaneous ridge between
medial and lateral malleolus blocks superficial peroneal nerve.
1. Stoelting RK, Miller RD. Basics of Anesthesia. 4th edition. Churchill Livingstone. New York, NY. 2000:192. 17. E Substantia gelatinosa Morphine acts at multiple sites (brain, spinal and peripheral tissues) and involves effects on
mu1, mu2, sigma and delta receptors. Morphine and related opioids selectively act on
neurons and neurotransmitters that transmit and modulate nociception. At the spinal cord
level morphine hyperpolarizes the neurons in the substantia gelatinosa via the mu2
receptors of the dorsal spinal cord thus decreasing the afferent transmission of nociceptive
impulses to the brain. Morphine also decreases the release of neurotransmitters involved
in the transmission of nociception such as substance P in the dorsal horn of spinal cord.
1. Barash PG, Cullen BF, Stoelting RK. Handbook of Clinical Anesthesia. 4th edition. Lippincott Williams & Wilkins. 2001:161.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
105
18. B Formation of increased ionized fraction of local anesthetics at the site of infection due to local tissue acidosis Local anesthetics exist in ionized and non ionized forms at physiologic pH. However, the
ratio of the two forms (non ionized to ionized) varies depending on the Pka of local
anesthetics and the pH of surrounding media. The non ionized form is the lipid soluble
form and is the primary determinant of local anesthetic potency. Since the non ionized
form is lipid soluble, it crosses the lipophilic nerve sheath to gain access to sodium channels
in the nerve membrane. Once inside the nerve sheath, the non ionized form of local
anesthetic is converted to the ionized form because of a lower pH. The ionized form binds
to Na channels to block nerve conduction. In this question, tissue necrosis, lactic acid
production at the infection site increases the ionized fraction of lidocaine (ionized form is
not lipid soluble) which limited the diffusion of local anesthetics through the nerve sheath
to gain access into the nerve to block impulse conduction. As a result infiltration of local
anesthetic produced a very poor block.
1. Stoelting RK, Miller RD. Basics of Anesthesia. 4th edition. Lippincott Williams & Wilkins. 2000:83. 19. B Bupivacaine induced sympathectomy leading to significant decrease in pre load due to peripheral vasodilation and venous pooling During a TURP procedure the patient is usually in the lithotomy position. The resulting
sympathectomy produced by bupivacaine after a spinal will not significantly alter the
preload since little pooling is occurring in the lower extremities while in the lithotomy
position. Transfer of the patient to a regular bed reverses this and results in significant
venous pooling in the lower extremities. This lead to profound hypotension with/without
nausea and vomiting due to decrease in venous return to the heart, decrease cardiac
output and decrease systematic vascular resistance. Administration of phenylephrine would
have been an appropriate action.
1. Stoelting RK and Miller RD. Basics of Anesthesia. 4th edition. Lippincott Williams & Wilkins. 2000:177.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
106
20. B Prilocaine can cause fetal methemoglobinemia Of all the amide drugs prilocaine is one of the safest drugs. It is equipotent with lidocaine
and has slightly longer duration of action. It is metabolized to O-toluidine, which can
reduce hemoglobin to methemoglobin. It is not used during labor anesthesia because “top
up” dose may be higher than the toxic dose, which may cause fetal cyanosis.
Methemoglobinemia is treated by administration of methylene blue or ascorbic acid. The
later is not used as often.
1. Wildsmith JAW, Armitage EN, McClure JH. Principles and Practice of Regional Anesthesia. 3rd edition. Churchill Livingstone. 2003:70. 21. C Obtain MRI of the lumbar spine and request a neurological consult It is extremely difficult to detect any bleeding into the epidural space, which may go
undetected. The earliest neurological symptoms and signs (back pain and pressure)
caused by hematoma are easily confused with epidural block. Time is of the essence
because, if the spinal cord compression persists for longer than 6-12 hours, catastrophic
paralysis may result due to spinal cord compression. If the sensory or motor losses
progress or outlast the expected duration of action of local anesthetics, neurological advice
should be sought and both CT and MRI be ordered. If a hematoma is diagnosed, then the
patient must have an emergent laminectomy and decompression to avoid the risk of
paralysis. Coagulopathy therefore represents a relative contraindication. The degree of
coagulopathy at which it becomes unsafe to perform regional anesthesia is highly
controversial.
1. Wildsmith JAW, Armitage EN, McClure JH. Principles and Practice of Regional Anesthesia. 3rd edition. Churchill Livingstone. 2003: 162.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
107
22. E Sacral cornu Caudal block provides excellent pain control and reduces the stress response to surgery.
Accurate location of sacral cornu, which represents unfused laminae of the fifth sacral
segment, is essential for performing a caudal block. The posterior superior iliac spine,
coccyx, greater trochanter of femur and iliac crest are the landmarks for a sciatic nerve
block using the posterior approach. In the posterior approach to sciatic nerve block a
straight line is drawn connecting the greater trochanter and posterior superior iliac spine.
A perpendicular line is drawn from the mid point inferiorly. A 3.5 inch, 22 gauge needle is
inserted 5 cm caudad, and 25 ml of local anesthetics is injected. This point of needle
insertion should lie on a line drawn between the coccyx and the top of greater trochanter.
1. Wildsmith JAW, Armitage EN, McClure JH. Principles and Practice of Regional Anesthesia. 4th edition. Churchill Livingstone. 2003:220. 23. D Increased protein binding Lipid solubility of local anesthetics correlates with potency, which increases as the total
number of carbon atoms in the molecule increase. Onset of action depends upon relative
concentration of non-ionized (lipid soluble) to ionized water-soluble form. Only lipid soluble
form diffuses across the neural sheath and nerve membranes. Once inside the cell only the
charged cation forms actually bind to the receptor. Local anesthetics with ester bond are
hydrolyzed by esterases. The duration of action of local anesthetics is associated with
protein binding (alpha-1 acid glycoprotein).
1. Morgan GE, Mikhail MS, Murray MJ. Clinical Anesthesia. 3rd edition. McGraw Hill. New- York. 2002: 235. 24. A Horner’s syndrome due to cervical sympathetic block Interscalene block is one of the three approaches for brachial plexus block. The
complications associated with this approach are related to the structures located in the
vicinity of block. The Horner’s syndrome due to spread of local anesthetic to cervical
sympathetic chain on the anterior vertebral body is common. The symptoms of this patient
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
108
are due to Horner’s syndrome which consists of: miosis, anhydrosis, ptosis, enophthalmos,
flushing and sweating. Proximity of other nerves (phrenic and recurrent laryngeal) makes
them susceptible to block manifested as dyspnea and hoarseness. Other complications
include intra-arterial injection into the vertebral artery, which can produce seizure and
inadvertent injection into epidural, subarachnoid and subdural spaces manifested as apnea.
Advancing needle too far, especially in the lateral direction, can result in a pneumothorax.
1. Morgan EG, Mikhail MS, Murray MJ. Clinical Anesthesia. 3rd edition. McGraw Hill. New York NY. 2002:289. 25. A Using a local anesthetic with high protein binding Important factors one should keep in mind while performing the epidural block include
onset, duration, quality (density of block) and spread of block. The following factors will
increase the duration of epidural block:
(i) Increased protein binding
(ii) Addition of vasoconstrictors
(iii) Increased concentrations
The later also increase the quality and onset of block. The spread of block is influenced by
volume, age, pregnancy, site (greater spread with thoracic than lumbar epidural), obesity
and height.
1. Wildsmith JAW, Armitage EN, McClure JH. Principles and Practice of Regional Anesthesia. 3rd edition. Churchill Livingstone. 2003:151. 26. E Common peroneal nerve injury The most common lower extremity nerves damaged because of compression or stretching
from improper positioning or improper padding are: peroneal, sciatic, saphenous and
occasionally obturator or posterior tibial nerves. The common peroneal nerve is a branch of
the sciatic nerve which branches into posterior tibial and peroneal nerves. Peroneal nerve
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
109
runs behind the head of fibula and around its neck. Its stimulation evokes dorsiflexion of
foot. It is the most frequently damaged nerve in the lithotomy position due to compression
between the head of fibula and the metal frame used to support the leg. Proper padding
and other precautions to decrease the incidence of this type of injury are essential. The
injury to the common peroneal nerve manifests as foot drop, loss of dorsal extension of
toes and inability to evert the foot.
1. Stoelting RK, Miller RD. Basics of Anesthesia. Churchill and Livingstone. 4th edition. 2000:206. 27. E Urinary retention
The disadvantage of epidural opioids is in the increase in unwanted effects such as nausea,
vomiting, pruritus, respiratory depression and urinary retention. Pruritus, nausea, vomiting
and respiratory depression can be reversed by smaller doses of naloxone without reversing
opioid analgesia. You may need higher doses 0.5 µg/kg to 2 µg/kg repeated at 10 minutes
interval to reverse the urinary retention. Urinary retention, seen after both regional and
systematic morphine administration, is caused by complex effects on central and peripheral
neurogenic mechanisms which results in dyssynergia between the bladder detrusor muscle
and the urethral sphincter relaxation. Also, urinary retention seems to be mediated
through several receptors. This may partly explain the resistance to naloxone
administration. Alternatively restricting the opioid dose can minimize the impact of side
effects.
1. Wildsmith JAW, Armitage EN, McClure JH. Principles and Practice of Regional Anesthesia. Churchill and Livingstone. 3rd edition. 2003:279. 28. B Duration of tourniquet inflation Following exsanguinations of arm or leg with an Esmarch bandage, the tourniquet is
inflated 300 mmHg or about 2.5 times the patient’s systolic blood pressure and 50 ml of
local anesthetics solution is administered. The duration of anesthesia depends upon the
duration of tourniquet inflation and not on other properties of local anesthetics such as
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
110
pKa, protein binding or the class of local anesthetics (ester or amide). Since the
distribution of local anesthetic is localized, a significant amount of local anesthetic
continues to diffuse through the blood and the nerve sheath to reach the nerve endings to
block the conduction without reaching the systematic circulation. Therefore, so long as the
tourniquet remains inflated, local anesthetic will continue to block nerve conduction.
Interestingly, analgesia produced with ropivacaine will be longer lasting than with lidocaine
though both produce comparable regional anesthesia.
1. Stoelting RK, Miller RD. Basics of Anesthesia. 4th edition. Churchill and Livingstone. 2000:195. 29. A Femoral, lateral femoral cutaneous and sciatic nerves Lumbosacral plexus (L2-S3) is the main nerve supply of lower extremity. The hip and knee
joints are supplied by femoral, sciatic and obturator nerves. For unilateral operation below
the knee, femoral and sciatic nerves block are sufficient to produce surgical anesthesia
because both sensory and motor innervations come from sciatic and femoral nerves.
However, above the knee block of these two nerves (sciatic and femoral) is not sufficient to
produce surgical anesthesia. For surgeries above the knee, one needs to block additional
nerves which include: lateral femoral cutaneous nerve block or three-in-one block, which is
block of femoral, lateral femoral cutaneous and obturator nerves. This block also provides
analgesia for tourniquet application during the surgical procedure.
1. Wildsmith JAW, Armitage EN, McClure JH. Principles and Practice of Regional Anesthesia. Churchill and Livingstone. 3rd edition. 2003:219. 30. A Inform the surgeon of possible bladder perforation and ask for termination of the procedure as soon as possible The incidence of bladder perforation during a TURP is approximately 1%. An awake patient
under regional anesthesia complaining of nausea, diaphoresis and lower abdominal pain
most likely has a bladder perforation. In contrast, patients under general anesthesia may
only show hypo- or hypertension with associated bradycardia. Other complications of TURP
are hemorrhage, TURP syndrome, hypothermia, septicemia and disseminated intravascular
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
111
coagulation. TURP syndrome is manifested as headache, restlessness, confusion,
hypotension or hypertension or seizures. These symptoms are due to circulatory fluid
overload from hypotonic non- electrolyte solution such as glycine 1.5% or a mixture of
sorbitol 2.7% and mannitol 0.54%. Other complications are hyponatremia, hyposmolarity,
fluid overload, hemolysis, and solute toxicity (glycine and sorbitol).
1. Morgan GE, Mikhail MS, Murray MJ. Clinical Anesthesiology. 3rd edition. McGraw Hill. New York NY. 2002:695. 31. E Verapamil Direct cardioversion may be used to terminate supraventricular and ventricular tachycardia.
Digitalis induced tachycardia or tachycardia due to multifocal foci are not responsive to
cardioversion. Had this patient received general anesthesia, a cardioversion would have
been an appropriate treatment. However, this patient is awake and under the
circumstances choice E, verapamil is the best choice. Verapamil is highly effective in
terminating the paroxysmal supraventricular tachycardia either due to atrial fibrillation or
flutter.
1. Stoelting RK. Pharmacology and Physiology in Anesthetics Practice. 3rd edition. Lippincott-Raven publishers. Philadelphia. 1999:341. 2. Morgan EG, Mikhail MS, Murray MJ. Clinical Anesthesiology. 3rd edition. McGraw Hill New York NY. 2002:472. 32. D Epidural hematoma The neurological symptoms and signs of epidural hematoma can be very confusing as they
are very similar to epidural block. Continued progression or prolonged duration of block
should alert the anesthesiologist and a neurological consult with further work up be sought.
Anterior spinal artery ischemia manifests itself as painless paralysis of the legs and
sphincters and generally is due to profound hypotension or surgical interruption of the
blood supply to the cord. Important signs of epidural abscess are pyrexia and leukocytosis
with associated back pain and tenderness. They generally appear 3 –4 days after the block.
MRI of spinal cord and determination of CSF protein levels are very helpful in the diagnosis.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
112
Staphylococcus aureus is the most common causative agent. Adhesive arachnoiditis is due
to infection or the presence of detergent in local anesthetics preparation.
1. Wildsmith JAW, Armitage EN, McClure JH. Principles and Practice of Regional Anesthesia. Churchill and Livingstone. 3rd edition. McGraw Hill New York NY. 2002:136, 162-164. 33. C Celiac plexus block with alcohol Celiac plexus block is a sympathetic block, which provides pain relief from malignancy of
upper abdominal organs particularly pancreas. The ganglion is located retroperitoneally at
the lower part of the twelfth thoracic and upper part of first lumbar vertebrae. Initially a
trial diagnostic block is performed using 20-25 ml of 0.75% lidocaine or 0.25% bupivacaine
under fluoroscopic control. If trial is successful (seen as a pain relief), neurolytic block with
50% alcohol in 1% lidocaine or 7% phenol in water is performed 24-hours later. Other
blocks mentioned in the question will not completely relieve the intra-abdominal pain.
The complications (hypotension and diarrhea) of the block are generally temporary and are
due to parasympathetic predominance. Other rare complications include: intramuscular,
intrathecal, epidural injections, sexual dysfunction, pneumothorax, bowel perforation,
kidney or liver puncture, retro-peritoneal hemorrhage or paraplegia secondary to spinal
cord ischemia.
1. Barash PG, Bruce CF, Stoelting,RK. Clinical Anesthesia. Lippincott-Raven Publishers. 3rd edition. 1997:371-372. 34. A Precipitation when mixed with an equal volume of thiopental Most of CSF is formed in the choroids plexus while a small fraction (10%) is derived from
brain substance. CSF is removed via the arachnoid villi. The CSF maintains a physiologic
stable environment. It is a colorless fluid with specific gravity of 1.003 to 1.009, pH 7.39-
7.5, contains glucose 40-80 mg/dl, protein 15-45 mg/dL, sodium 138 mEq/L, potassium 2-3
mEq/L, calcium 2-3 mEq/L magnesium 2-3 mEq/L, chloride 1-4 mEq/L. The normal
pressure of CSF ranges between 60 and 150 mmHg. The presence of CSF can be
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
113
confirmed by the formation of precipitation when mixed with an equal volume of thiopental
or by measuring glucose.
1. Longnecker DE, Tinker JH, Morgan GE. Principles and Practice of Anesthesiology. 2nd edition. Mosby Publishing Co. 1998:1367. 35. C Administration of nebulized racemic epinephrine Onset of inspiratory stridor in a postoperative patient can be due to laryngospasm,
laryngeal edema or vocal cord dysfunction. Laryngospasm can be triggered by excessive
secretions which stimulates the superior laryngeal nerve. Laryngeal edema may be caused
by an allergic drug reaction or a traumatic intubation. Subglottic edema in children is
produced when intubated with a large size tube with no leak around the tube.
Administration of humidified oxygen is usually required. Racemic epinephrine (0.5 ml of a
2% solution diluted to a volume of 2 to 4 ml) administered by a nebulizer is indicated if
symptoms persist. Administration of glycopyrrolate or corticosteroids will not help to
resolve the laryngeal edema.
1. Morgan GE, Mikhail MS, Murray MJ, (eds.). Clinical Anesthesiology. 3rd edition. Lange Medical Books/McGraw-Hill Medical Publishing Division. New York, NY. 2002:780. 36. D Decrease Decrease Presence of a large air bubble in the blood containing syringe will decrease both PaO2 and
PaCO2 measured because both O2 and CO2 diffuse from the blood into the bubble. This is
particularly true if blood gas measurement is carried out at higher oxygen partial pressures
or when the patient is on high FiO2 during mechanical ventilation because of greater
diffusion gradient. Thus removal of air bubble, before capping the syringe and placing it in
the ice-water, is essential. This will not affect oxygen binding to hemoglobin or oxygen
saturation.
1. Miller RD (eds.). Anesthesia. 5th edition. Churchill Livingstone. New York, NY. 2000:1263.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
114
37. E Atenolol Critical aortic stenosis exists when aortic orifice is reduced to 0.5 – 0.7 cm2 (normal is 2.5 –
3.5 cm2). Because of the long latency period most patients with aortic stenosis develop
diastolic dysfunction as a result of an increase in ventricular mass and fibrosis. This leads to
increased myocardial oxygen demand and a decrease in myocardial oxygen supply as a
result of compression of intramyocardial coronary vessels. Maintenance of normal sinus
rhythm, heart rate, and intravascular volume is critical in patients with aortic stenosis.
Tachycardia potentiates myocardial ischemia because of impaired coronary perfusion due
to decreased filling, decreased diastolic pressure and decreased perfusion. This usually
manifest as chest pain. Therefore, the use of a beta blocker (atenolol) to reduce the heart
rate, oxygen demand and to increase filling with increased diastolic pressure will improve
the coronary perfusion and is the most appropriate action.
1. Morgan GE, Mikhail MS, Murray MJ, (eds.). Clinical Anesthesiology. 3rd edition. Lange Medical Books/McGraw-Hill Medical Publishing Division. New York NY. 2002:416. 38. C A patient with an acute episode of pulmonary edema following an abdominal surgery In the case of a patient with an acute episode of pulmonary edema, increasing
transpulmonary distending pressure, with continuous positive-pressure therapy can
increase lung volume, improve compliance, reverse ventilation/perfusion mismatching and
redistribute extravascular lung water from interstitial space toward peribronchial and
perihilar region. This improves arterial oxygenation. The treatment of hypoxemia in
patients with chronic obstructive pulmonary disease (COPD) is supportive with
supplemental oxygen. In patients with pneumothorax continuous positive pressure
ventilation in the absence of a chest tube can make a partial pneumothorax worst. CPAP
will not significantly improve arterial oxygen tension in alveolar proteinosis because of
increased diffusion impairment.
1. Morgan GE, Mikhail MS, Murray MJ, (eds.). Clinical Anesthesiology. 3rd edition. Lange Medical Books/McGraw Hill Publishing Division. New York, NY. 2000:968.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
115
39. B An orotracheal intubation in the operating room with volatile anesthetics in the presence of an ENT This patient has an acute epiglottitis. The most appropriate action is an orotracheal
intubation in the operating room after a slow induction with a volatile anesthetic such as
sevoflurane or halothane in the presence of an ENT physician for possible tracheostomy.
Neuromuscular blocking drugs are not administered because skeletal muscle paralysis could
result in total airway obstruction. Epiglottitis resolves in 48 to 96 hours and tracheal
extubation is performed in the operating room. Nasotracheal intubation and fiber optic
intubation is not recommended because sudden and total airway obstruction can occur.
Acute epiglottitis is a bacterial infection caused by Haemophilus influenza and treated with
ampicillin.
1. Stoelting RK, Miller RD. Basics of Anesthesia. 4th edition. Churchill Livingstone. New York NY. 2000:372. 40. A Place an oral airway until surgical correction can be accomplished This is a congenital form of choanal atresia. Nasal obstruction should be suspected in any
neonate who has good breathing efforts but in whom air entry is absent. Inability to pass a
small catheter through each naris confirms the diagnosis of unilateral or bilateral
anatomical or functional obstruction. An oral airway is placed until surgical correction can
be accomplished for anatomical obstruction or nasal suctioning is carried out for functional
obstruction. Heroin use by mother can cause congestion of the nasal mucosa and
obstruction which can be treated with phenylephrine nose drops. Orotracheal intubation or
a catheter through the mouth will not be appropriate.
1. Stoelting RK, Dierdorf SF. Anesthesia and coexisting disease. 4th edition. Churchill Livingstone. New York, NY. 2002:683-4.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
116
41. A 500 cc of Lactate Ringer The most appropriate course of action is intravenous administration of 500 ml of Lactate
Ringers solution. Hypertrophic obstructive cardiomyopathy leads to hypertrophy of left
ventricle and intraventricular septum. Marked left ventricular hypertrophy and septal
hypertrophy makes these patients vulnerable to myocardial ischemia and outflow
obstruction. Thus any drug or event that increases preload or afterload or decreases
myocardial contractility decreases outflow obstruction. Administration of metoprolol and
phenylephrine will be the next most appropriate action.
1. Stoelting RK, Dierdorf SF. Anesthesia and coexisting disease. 4th edition. Churchill Livingstone. New York, NY. 2002:125. 42. A Prevent laryngospasm during awake nasal intubation Superior laryngeal nerve, a branch of the vagus nerve branches into internal laryngeal and
external laryngeal nerves. The internal laryngeal nerve provides sensory innervation to the
vocal cord, epiglottis and arytenoids. It is located 1 cm below each greater cornu where it
penetrates the thyrohyoid membrane. This nerve is blocked by injection of lidocaine
through the thyrohyoid membrane below greater cornu. The external laryngeal nerve
provides motor innervation to the cricothyroid muscle which lengthens, tenses and adducts
vocal folds. Recurrent laryngeal nerve or inferior laryngeal nerve provides sensory
innervation below the vocal cords and larynx and motor innervation to all the muscles of
larynx except cricothyroid muscle. The glossopharyngeal (ninth cranial nerve) nerve
provides sensation to the posterior third of tongue and oropharynx. It is blocked by
bilateral injection of 2 ml of local anesthetics into the base of palatoglossal arch.
1. Morgan GE, Mikhail MS, Murray MJ, (eds.). Clinical Anesthesiology. 3rd edition, Lange Medical Books/McGraw-Hill, New York, NY. 2002:83.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
117
43. C Manage the child conservatively with oxygen, mist therapy and treat with nebulized racemic epinephrine (0.5 ml of a 2.25% solution in 2.5 ml of normal saline) Post-intubation croup is caused by glottic, laryngeal or tracheal edema. This can be
avoided if the smallest acceptable tracheal tube is utilized. Subglottic edema manifests as
a “barky cough” after tracheal extubation. Administration of humidified oxygen and
racemic epinephrine administered by a nebulizer is indicated. Intravenous administration
of dexamethasone is controversial.
1. Morgan GE, Mikhail MS, Murray MJ, (eds.). Clinical Anesthesiology. 3rd edition. Lange Medical Books/McGraw-Hill Publishing Division. New York, NY. 2002:79. 44. B Administer lidocaine 100 mg via the endotracheal tube Intraoperative wheezing most commonly results from reactive bronchospasm. The
differential diagnosis of intraoperative wheezing includes: mechanical obstruction of the
tube due to bleeding, secretions, kinking, pulmonary edema, pulmonary embolus,
aspiration of gastric contents and pneumothorax. Histamine and other inflammatory
mediators release associated with administration of numerous drugs, blood products,
contrast media, allergic or anaphylactic reactions can all produce wheezing.
Recognition of the cause of wheezing and treatment is crucial as wheezing may easily
progress to bronchospasm. Intraoperative treatment of wheezing include: increase in the
inspired concentration of oxygen, providing adequate depth of anesthesia, decompression
of abdomen if necessary, and checking the placement and patency of endotracheal tube.
This is supplemented with suctioning of endotracheal tube, use of anticholinergics drugs,
lidocaine, steroids and inhalation therapy with beta agonists.
1. Longnecker DE jr, Tinker JH, Morgan GE, (eds.). Principles and Practice of Anesthesiology. 2nd edition. Mosby. New York, NY. 1998:110.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
118
45. D Functional residual capacity Obesity is defined as body weight greater than 20% of ideal body weight or body mass
index of 28-35. Morbid obesity is defined as body mass index of greater than 35 or body
weight more than two times ideal body weight or greater than 100 lb. over ideal body
weight. Functional residual capacity (FRC) is decreased the most in morbidly obese
patients. Expiratory reserve volume is greatly decreased while lung residual volume
remains in the normal range. Forced expiratory flow rate and maximal mid expiratory flow
rate remains normal.
1. Duke J (ed.). Anesthesia Secrets. 2nd edition. Hanley and Belfus, Inc. Philadelphia, PA. 2000:284. 46. B Reoperation to relieve abdominal pressure Omphalocele is external herniation of abdominal viscera through the base of umbilical cord.
The incidence is 1 in 5,000 to 10,000 live births. Seventy five (75%) percent of the time it
is associated with Down’s syndrome, cardiac anomalies or Beckwith syndrome
(omphalocele, organomegaly, macroglossia and hypoglycemia). This patient had adequate
fluid resuscitation during surgery as evident from his urinary output. Following abdominal
wall closure, high intraoperative pressure interfered with abdominal organ perfusion
because the cavity is too small for viscera. In this particular case increased abdominal
pressure with decreased venous return from the lower extremities and decreased renal
perfusion lead to oliguria. A fluid challenge with lactate Ringers solution is the next most
plausible choice.
1. Barash PG, Cullen BF and Stoelting RK, (eds.). Clinical Anesthesia. 4th edition. Lippincott Williams & Wilkins. New York, NY. 2001:1185.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
119
47. A Postural hypotension, nasal stuffiness, decreased sweating and stable vital signs Once pheochromocytoma is diagnosed, outpatient therapy is initiated to establish alpha-
adrenergic receptor blockade (usually with phenoxybenzamine or less often with prazosin).
Stable vital signs, postural hypotension, nasal stuffiness are clues to adequate block.
Alpha-methyltyrosine inhibits tyrosine hydroxylase, which is a rate-limiting enzyme in
catecholamine biosynthesis. This medication is reserved for patients with metastatic
disease or in situations where surgery is contraindicated. The overall goal of medical
treatment before surgery is to minimized sympathetic outflow that commonly occurs with
induction and surgical stimulation
1. Morgan GE, Mikhail MS, Murray MJ, (eds.). clinical Anesthesiology. 3rd edition. Lange Medical Books. McGraw-Hill Medical Publishing Division. New York, NY. 2002:220-222. 48. A Enflurane-specific vaporizer is filled with halothane Vaporizers are agent-specific. An unintentional filling with a wrong anesthetic agent may
lead to overdose or underdose of an anesthetic agent. For example halothane with higher
vapor pressure (240 vs 175 of enflurane) will cause a 40% greater amount of anesthetic
vapor delivered to the patient. Besides, halothane is more potent than enflurane (lower
MAC). As a result filling of enflurane vaporizer with halothane could lead to delivery of
toxic dose of halothane. The converse is true if halothane vaporizer is filled with enflurane.
Same reasoning will apply if isoflurane vaporizer is filled with halothane.
1. Morgan GE, Mikhail MS, Murray MJ, (eds.). Clinical Anesthesiology. 3rd edition. Lange Medical Books. McGraw-Hill Medical Publishing Division. New York, NY. 2002:49. 49. A Increase FiO2 to 40% Opioids particularly meperidine is used most frequently for obstetrics pain relief. Neonatal
respiratory depression depends upon the total dose and the time interval between
administration and delivery. Maximal respiratory depression occurs with delivery between
1-3 hours after IM injection. However, less depression is seen if meperidine is given less
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
120
than one hour and more than four hours after delivery. The respiratory rate of this
newborn is in the normal range (40 to 60) with slightly low pulse rate (normal 120-160),
low PaO2 (normal 70) and slightly high PaCO2 (normal 40). The most appropriate action
would be to increase FiO2 to 40% and observe the patient.
1. Longnecker DE jr, Tinker JH, Morgan GE, (eds.). Principles and Practice of Anesthesiology. 2nd edition Mosby. New York, NY. 1998:1995. 50. D Nitrous oxide should be avoided because it will increase the intrapleural pressure and the size of pneumothorax Pneumothorax is the accumulation of gas within the pleural space. The etiology of
pneumothorax include: rupture of blebs and bullae, COPD, chest trauma, surgeries
involving thoracic cage and upper abdominal wall, high volume or high pressure positive
pressure ventilation. In this question choice D, is the most appropriate because the use of
nitrous oxide during the surgery will cause preferential transfer of nitrous oxide into the air-
filled cavity (the blood:gas partition of nitrous oxide is 34 times greater than that of
nitrogen), thus making the pneumothorax worst. Chest tube should not be clamped but put
to water seal to ensure removal of air from the pleural space and continued expansion of
lung. High tidal volume will expand the pneumothorax. Signs of pneumothorax include:
wheezing, decreased breath sounds, increased peak inspiratory pressures with hypoxemia,
decreased pulmonary compliance and hypotension.
1. Stoelting RK, Miller RD. Basics of Anesthesia. 4th edition. Churchill Livingstone. New York, NY. 2000:280. 51. D Desflurane Desiccated (dehydrated) soda lime and Baralyme can degrade inhaled anesthetics to form
clinically significant concentrations of carbon monoxide (CO), which can result in
carboxyhemoglobinemia. Desflurane is capable of producing the greatest concentration of
carbon monoxide when exposed to desiccated absorbent. Highest levels of CO are formed
after prolonged contact between absorbent and inhaled anesthetics and after absorbent
disuse for at least 48 hours. Reports of CO poisoning are most common in patients
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
121
anesthetized on Monday morning, because continuous high flows (10 L/min) from the
anesthesia machine over the weekend results in dehydration of the absorbent.
Factors that appear to increase the production of CO include:
a) The inhaled anesthetic used; desflurane produces the greatest concentration of
carbon monoxide. In order of CO production from greatest to least:
Desflurane ≥ Enflurane ≥ Isoflurane >> Halothane = Sevoflurane
b) The dryness of the absorbent - dehydrated absorbent produces more CO - when
absorbent moisture content is normal, no measurable levels of CO are produced
with desflurane, enflurane or isoflurane
c) The type of absorbent - Baralyme produces more CO than soda lime
d) The temperature - increased temperature increases CO production
e) The anesthetic concentration - high concentrations of anesthetics produces more
CO
Xenon is a noble gas that has anesthetic properties. Xenon has a MAC of 71%, making it
more potent than nitrous oxide (MAC 104%). Xenon is nonexplosive, non-pungent, and
odorless. Xenon in not known to interact with desiccated absorbent.
1. Miller R. Anesthesia. 5th edition. Churchill Livingstone. New York NY. 2000:194-5. 52. C CBF increases, CMRO2 increases, ICP increases Nitrous oxide (N2O) is an inhalational anesthetic whose effects appear to differ from other
inhalational agents. All volatile anesthetics tend to decrease cerebral metabolic rate of
oxygen (CMRO2) while increasing cerebral blood flow (CBF) and intracranial pressure
(ICP). This phenomenon is called uncoupling. Nitrous oxide on the other hand has a
different effect. When given alone it tends to cause an increase in CBF and ICP and
although somewhat controversial, the consensus is that it also increases CMRO2. When
given with a more potent volatile anesthetic, the increase in CMRO2 is not seen but a more
profound increase in CBF and ICP are seen than what would be expected with the volatile
anesthetic alone reflecting the greater vasodilating effect of N2O on cerebral circulation.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
122
Interesting, when N2O is given with IV anesthetics, the effects on CMRO2 or CBF are
decreased or eliminated.
The following table summarizes these effects:
ANESTHETIC
CBF
CMRO2
ICP
Halothane
↑ ↓ ↑
Isoflurane
↑ ↓ ↑
Desflurane
↑ ↓ ↑
Sevoflurane
↑ ↓ ↑
N2O alone
↑ ↑ ↑
N2O with IV Anesthetics
O O O
N2O with Volatile Anesthetics
↑ O ↑
1. Miller R. Anesthesia. 5th edition. Churchill Livingstone. New York NY. 2000:710-711.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
123
53. D Normeperidine Meperidine is metabolized through two hepatic routes:
1. Hydrolysis to meperidinic acid
2. N-demethylation to normeperidine which then undergoes hydrolysis to
normeperidinic acid
Excretion of the end products normeperidinic acid and normeperidine is primarily renal.
The acid metabolites, meperidinic acid and normeperidinic acid are inert and do not exert
any pharmacological effects. Normeperidine however, is pharmacologically active (half
the analgesic property of meperidine) and with CNS toxicity. Normeperidine has a longer
half-life (15-20 hours) than meperidine itself (3-6 hours). Therefore, prolonged
administration (such as patient controlled analgesia) may lead to toxicity due to
accumulation of normeperidine especially when renal impairment is present.
Normeperidine can produce signs of central nervous system excitation. These signs include
tremors, myoclonus, and grand mal seizures. Although meperidine levels may be within
standard analgesic range, normeperidine levels may sometimes be at toxic levels due to its
longer half-life. In situations where prolonged administration of an opioid is anticipated, a
drug without an active metabolite should be considered. Naloxone does not reverse
normeperidine toxicity.
Laudanosine is a active metabolite of atracurium, a non-depolarizing muscle relaxant. It too
can produce seizures with toxic levels. Norcodeine is a metabolite of codeine and not
meperidine, and is not implicated in any CNS toxicity.
1. Stoelting, RK. Pharmacology and Physiology in Anesthetic Practice. 3rd edition. Lippincott-Raven. Philadelphia.1999:91-93.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
124
54. D Superior laryngeal nerve The superior laryngeal nerve (a branch from the vagus nerve - Cranial nerve X)
provides sensation from the epiglottis to the vocal cord (i.e., sensation above the cords). A
superior laryngeal block will therefore provide anesthesia to this area. The block is
performed with the patient supine and the greater cornu of the hyoid bone located. The
needle is walked off the greater cornu and into the thyrohyoid membrane where 2 to 3 ml
of local anesthetic is injected. The block is repeated on the opposite side.
The recurrent laryngeal nerve provides sensation to the tracheal below the cords, while
the sphenopalatine nerve provides sensation to the mucosa of the nares. Sensation of
the posterior oral pharynx is by the lingual nerve (a branch of the mandibular division of
Cranial nerve V) and the posterior 2/3rd of the tongue is by the glossopharyngeal nerve
(Cranial nerve IX).
1. Miller R. Anesthesia. 5th edition. Churchill Livingstone. New York NY. 2000:1541-1543. 55. C A-delta Normal body core temperature is maintained within ± 0.2oC (the inter threshold range) of
its target temperature of 37oC. To accomplish this, normal thermoregulation requires three
components:
1. Afferent input from peripheral sensing sites
2. Central regulation or control by the hypothalamus
3. Efferent responses in the form of behavior or autonomic responses such as
sweating and vasodilation for temperature increases and vasoconstriction and
shivering for decreases in temperature.
Afferent cold input to the hypothalamus is via A-delta nerve fibers while warm
temperature information travel by unmyelinated C fibers. The hypothalamus regulates
temperature by comparing this afferent temperature information with threshold
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
125
temperature for heat and cold. When the input temperature exceeds a threshold, the
appropriate response is initiated to maintain adequate body temperature.
1. Miller R. Anesthesia. 5th edition. Churchill Livingstone. New York NY. 2000:1368. 56. E Expiratory reserve volume (ERV) + residual volume (RV) The volume of gas that remains in the lung after a normal expiration is defined as the
functional residual capacity (FRC). It comprises of expiratory reserve volume (ERV) and
residual volume (RV). A reduction in FRC increases shunting and causes arterial hypoxemia.
Other capacities of interest include:
a. Inspiratory capacity (IC) composed of inspiratory reserve volume + tidal volume
b. Total lung capacity (TLC) composed of IC + FRC
c. Vital capacity (VC) composed of inspiratory reserve volume + expiratory reserve
volume + tidal volume 1. Miller R. Anesthesia. 5th edition. Churchill Livingstone. New York NY. 2000:590. 57. A Hypercarbia The oculocardiac reflex is a reflex arc that involves the trigeminal nerve (the afferent limb)
and the vagus nerve (efferent limb). This reflex can be induced by pressure on the eye
globe, traction of extraocular muscles, trauma to the eye, and even after a retrobulbar
block administration. The most common manifestation of the oculocardiac reflex is sinus
bradycardia although a wide array of other cardiac dysrhythmias can also be elicited.
Conditions that can potentiate this reflex are hypercarbia, hypoxemia, light anesthesia and
conditions that result in increase vagal tone. Hypertension and hypotension are not
associated with an increased incidence of this reflex. 1. Miller R. Anesthesia. 5th edition. Churchill Livingstone. New York NY. 2000:2180. 2. Barash P, Cullen B, Stoelting R. Clinical Anesthesia, 4th edition, J.B. Lippincott. Philadelphia. 2001:973-974.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
126
58. D Administer fresh frozen plasma Administration of fresh frozen plasma (FFP) is best for urgently reversing the anticoagulant
effects of warfarin (Coumadin). Recommended dose for reversal of warfarin is 5 to 8 ml/Kg
of FFP.
Administration of vitamin K, subcutaneous or intravenous, can also be use for reversing
warfarin effects, but improvement in coagulation may not be seen for hours and full
restoration of coagulability may not be seen for at least 24 hours regardless of route of
administration.
Protamine is used to reverse the effects of heparin and has no effect on the anticoagulant
warfarin. Cryoprecipitate is used for correction of factor VIII deficiency and von
Willebrand’s factor deficiency. Albumin contains no coagulation factors and is therefore
ineffective therapy for reversing warfarin anticoagulant effects.
1. Miller R. Anesthesia. 5th edition. Churchill Livingstone. New York NY. 2000:1613. 59. E Measuring pulmonary artery pressures Neurosurgical procedures involving the posterior fossa can often be complicated with the
occurrence of venous air emboli. The incidence is somewhere between 30 and 50% in
patients operated in the sitting position. Air entering the venous circulation eventually
makes its way to the pulmonary arterioles and results in intense vasoconstriction. This
results in ventilation/perfusion mismatch, interstitial pulmonary edema, and reduced
cardiac output as the pulmonary vascular resistance increases. Large volumes of air can
prevent cardiac ejection by causing an “air lock” effect.
Monitors used intraoperatively for the detection of venous air embolus include (from most
sensitive to least sensitive):
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
127
1. Transesophageal echocardiography (TEE)
2. Precordial Doppler
3. Pulmonary artery catheter (Detection of increases in pulmonary artery pressure)
4. Capnography (Detection of decreases in end-tidal CO2)
5. Monitoring end-tidal N2 (Detection of increases in end-tidal N2)
The precordial Doppler ultrasound transducer is the most sensitive noninvasive monitor
and the earliest detector of venous air embolism while the TEE is the most sensitive
invasive monitor but is cumbersome and expensive to use. The detection of pulmonary
hypertension (increase in pulmonary artery pressures) is slightly more sensitive than
capnography. Monitoring for air (end-tidal N2) may not detect subclinical air emboli.
1. Cottrell, JE, Smith, DS. Anesthesia and Neurosurgery. 4th edition. Mosby. St. Louis. 2001:340-345. 60. E Tracheal intubation Anatomical dead space is ventilation of the nasal and oropharynx to the terminal and
respiratory bronchioles, where little gas exchange occurs. Anatomical dead space
ventilation is approximately equal to 2 ml / kg ideal body weight (or approximately 150 ml).
Anatomical dead space accounts for the majority of physiologic dead space (physiologic
dead space is anatomical dead space plus alveolar dead space).
Maneuvers that increase dead space include positioning (supine to upright position), neck
extension, and use of bronchodilators. Ventilation by mask can add approximately 100 ml.
to the anatomical dead space from the mask itself. Tracheal intubation on the other hand,
reduces anatomical dead space because ventilation now bypasses the nasal and
oropharynx area.
1. Lumb, AB. Nunn’s Applied Respiratory Physiology. 5th edition. Butterworth-Heinemann. 2000:178-179.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
128
61. E Higher systolic pressure and lower diastolic pressure The arterial pressure waveform is the results of blood ejected from the left ventricle into
the aorta. The flow of blood is not only from the ejection of blood from the ventricle but
propagation of the waveform by reflectance due to the distensibility and contraction of the
arterial vessels. As this arterial pressure waveform travels through peripheral arterioles a
phenomenon of distal pulse amplification occurs. Compared to the aorta, peripheral
arterial waveforms have a higher systolic pressure, a lower diastolic pressure and a wider
pulse pressure. The mean arterial pressure however remains greater in the aorta compared
to the peripheral arterial vessels.
1. Miller R. Anesthesia. 5th edition. Churchill Livingstone. New York NY. 2000:1137-1142. 2. Barash P, Cullen B, Stoelting R. Clinical Anesthesia, 4th edition, J.B. Lippincott. Philadelphia. 2001:875.
62. C Etomidate Etomidate used for induction of anesthesia causes suppression of adrenal function by
producing a dose dependent inhibition of the conversion of 11-deoxycortisol to cortisol. The
specific enzyme inhibited by etomidate appears to be 11-beta-hydroxylase. This enzyme
inhibition lasts 4 to 8 hours after an induction dose of etomidate (with documented adrenal
compromise up to 24 hours). Studies however, suggest that etomidate is safe and that this
adrenal suppression is probably clinically insignificant.
None of the other intravenous induction medications are known to cause adrenal
suppression.
1. Miller R. Anesthesia. 5th edition. Churchill Livingstone. New York NY. 2000:247-248. 2. Barash P, Cullen B, Stoelting R. Clinical Anesthesia, 4th edition, J.B. Lippincott. Philadelphia. 2001:148.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
129
63. D Atypical pseudocholinesterase Mivacurium is a short-acting nondepolarizing muscle relaxant with a duration of 10 to 20
minutes. Unique to mivacurium is its clearance. Mivacurium is hydrolyzed by plasma
cholinesterase (pseudocholinesterase) an enzyme that also is responsible for the
breakdown of succinylcholine. Presence of atypical pseudocholinesterase variants will result
in prolonged paralysis by succinylcholine and mivacurium.
Mivacurium is not depended on renal clearance or non-specific esterase metabolism.
Although hypothermia is known to prolong paralysis of nondepolarizing muscle relaxants
and inhaled anesthetics enhance their muscle relaxant effects, neither would be expected
to prolong mivacurium effects to the extent described.
1. Stoelting, RK. Pharmacology and Physiology in Anesthetic Practice. 3rd edition. Lippincott-Raven. Philadelphia. 1999:191-192. 2. Barash P, Cullen B, Stoelting R. Clinical Anesthesia, 4th edition, J.B. Lippincott. Philadelphia. 2001:538-540. 64. D Eu Eu Inherited variants of pseudocholinesterase can prolong the duration of action of
succinylcholine and mivacurium. Prolonged paralysis can occur with a recommended
intubation dose. These patients usually have no symptoms.
Normal pseudocholinesterase activity is inhibited by 80% by dibucaine, an amide local
anesthetic, while atypical pseudocholinesterase (homozygous) is inhibited by only 20%.
This dibucaine number (level of inhibition) can therefore be used to characterize the
different pseudocholinesterase variants. It is important to recognize that the dibucaine
number reflects the quality of plasma cholinesterase enzyme activity (i.e., ability to
hydrolyzed succinylcholine) and not the quantity of enzyme that is circulating in the
plasma.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
130
VARIANTS OF PLASMA CHOLINESTERASE ENZYME
GENOTYPE DIBUCAINE NUMBER (% inhibited)
DURATION (succinylcholine)
INCIDENCE
Homozygous (Eu Eu) 80 5 - 10 min normal
Heterozygous (Eu Ea) 40 - 60 20 min 1 in 480
Homozygous atypical (Ea Ea) 20 60 - 180 min 1 in 3200
Genotype Eu Eu represents the normal homozygous type of pseudocholinesterase.
Over the years two silent variants (Es) as well as a plasma cholinesterase inhibited by
fluoride (Ef) have been discovered. (A fluoride number like a dibucaine number can be
generated.)
Significant prolongation of succinylcholine and mivacurium occurs with the following
genotypes: EaEa, EfEf, EaEs, EfEa, and EsEs.
1. Stoelting, RK. Pharmacology and Physiology in Anesthetic Practice. 3rd edition. Lippincott-Raven. Philadelphia. 1999:191-192. 2. Barash P, Cullen B, Stoelting R. Clinical Anesthesia, 4th edition, J.B. Lippincott. Philadelphia. 2001:538-540. 65. E Pancuronium The major concern in using muscle relaxants in patient with renal dysfunction is that
duration of action may be prolonged; especially those depended on renal clearance.
Pancuronium is a long-acting nondepolarizing muscle relaxant that is depended on renal
clearance for termination of its effects. Approximately 80% of a single dose of pancuronium
is excreted by the kidneys unchanged. Its use in a patient with end stage renal disease is
unwise.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
131
Atracurium and cis-atracurium duration of action is not prolonged in renal disease. The
reason is that metabolism of these nondepolarizing muscle relaxants is not depended on
normal renal function. Instead, atracurium is depended on Hoffman elimination and ester
hydrolysis while cis-atracurium is mostly entirely depended on Hoffman elimination.
Rocuronium is primarily depended on the liver for its elimination and therefore its duration
of action is not prolonged in patients with end stage renal disease.
Succinylcholine is not depended on renal clearance. Although pseudocholinesterase is
known to be decrease in renal failure, prolonged paralysis is not clinically significant when
using succinylcholine. Concerns of exaggerated hyperkalemia in patients with renal
diseases and the use of succinylcholine has not be supported by recent controlled studies,
and therefore has been shown to be safe to use in patients with chronic renal failure.
1. Miller R. Anesthesia. 5th edition. Churchill Livingstone. New York NY. 2000:423. 2. Barash P, Cullen B, Stoelting R. Clinical Anesthesia, 4th edition, J.B. Lippincott. Philadelphia. 2001:1013-1014. 66. D Prominent U waves Gastrointestinal losses of potassium are common in patients undergoing “bowel prep” for
intestinal surgical procedures. Electrocardiogram (ECG) changes consistent with
hypokalemia include flatten T waves, prominent U waves and ST segment depression.
Although these are classic ECG description, they may not be as sensitive as indicators for
hypokalemia.
Peaked T waves, widen QRS complexes with loss of P waves are more commonly seen with
hyperkalemia. Delta waves are consistent with Wolf-Parkinson-White (WPW) syndrome.
1. Barash P, Cullen B, Stoelting R. Clinical Anesthesia, 4th edition, J.B. Lippincott.-Philadelphia. 2001:186-189.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
132
67. A Less than 24 hours post-injury Hyperkalemia may result from the use of succinylcholine especially in those patients with
motor deficits due to spinal cord injuries. The severity of hyperkalemia depends on the
extent of paralysis. It is probably safe to use succinylcholine within the first 48 hours. After
this time, hyperkalemia severe enough to cause ventricular fibrillation and cardiac arrest
may occur. This is due to increase sensitivity of acetylcholine receptors to succinylcholine
and upregulation of these same receptors. Peak hyperkalemia levels occur between 4
weeks and 5 months.
1. Barash P, Cullen B, Stoelting R. Clinical Anesthesia, 4th edition, J.B. Lippincott. Philadelphia. 2001:1109. 68. E Ketamine Gamma aminobutyric acid (GABA) is primarily an inhibitory neurotransmitter. It interacts
with GABAA receptors, causing its chloride channel to open, hyperpolarizing the nerve and
reducing its excitability. Sodium thiopental, methohexital, propofol, etomidate and
benzodiazepines all seem to exert there effects by enhancing the action of GABA at these
receptors. Ketamine exerts its effects via the N-methyl-D-aspartate (NMDA) receptors.
1. Barash P, Cullen B, Stoelting R. Clinical Anesthesia, 4th edition, J.B. Lippincott. Philadelphia. 2001:127-129. 69. D Administer oxytocin Uterine atony is most common cause of postpartum hemorrhage. It often occurs
immediately after delivery. Uterine message and the infusion of oxytocin are initial
treatments. Oxytocin is a hormone secreted by the posterior pituitary. Synthetic
preparations of oxytocin are often use postpartum for its ability to contract uterine smooth
muscle and control postpartum bleeding. Oxytocin is often given by infusion.
Desmopressin (DDAVP) is a synthetic analogue of antidiuretic hormone (ADH) often used in
increasing von Willebrand factor. Vasopressin (ADH) is indicated for the treatment of
diabetes insipidus. Phenylephrine is a direct alpha agonist that would not have any effect
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
133
on uterine smooth muscle. Neostigmine is an anticholinesterase that is use to reverse the
effects of nondepolarizing muscle relaxants. 1. Stoelting, RK. Pharmacology and Physiology in Anesthetic Practice. 3rd edition. Lippincott-Raven. Philadelphia. 1999:422-424. 70. A Hypotension Uterine atony is most common cause of postpartum hemorrhage. It often occurs
immediately after delivery. Uterine message and the infusion of oxytocin are initial
treatments. Oxytocin is a hormone secreted by the posterior pituitary. Synthetic
preparations of oxytocin are often use postpartum for its ability to contract uterine smooth
muscle and control postpartum bleeding. Oxytocin is often given by infusion.
Given intravenously, oxytocin causes peripheral vasodilation of vascular smooth muscle.
The result is hypotension, with a reflex tachycardia. Patients that are hypovolemic may
experience an exaggerated hypotensive response. None of the other symptoms listed are
likely with oxytocin administration.
1. Stoelting, RK. Pharmacology and Physiology in Anesthetic Practice. 3rd edition. Lippincott-Raven. Philadelphia. 1999:422-424. 71. E Stop ventilation The use of a laser, particularly in the area of the endotracheal tube, is at high risk of
igniting an airway fire. Everyone including the surgeon and anesthesiologist should have a
plan of action should an airway fire occur. Should a fire occur the first and immediate step
is to stop ventilation and disconnect the flow of gases (oxygen) to the airway. This should
be followed by removal of the endotracheal tube. Only after the fire has been extinguished
should ventilation by mask with 100% oxygen begin. This can be followed with reintubation
of the trachea to assess the extent of damage. Switching from oxygen to air would not
necessarily extinguish the fire, nor would stopping the use of volatile anesthetic, since in
both conditions; oxygen would still be present to sustain continued combustion. Nitrous
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
134
oxide also supports combustion just like oxygen. To reduce the risk of fire during laser
surgery, not more than 30% oxygen should be used.
1. Miller R. Anesthesia. 5th edition. Churchill Livingstone. New York NY. 2000:2210. 72. D Cis-atracurium Many medication used in the practice of anesthesia are know to cause a release in
histamine. Therefore, theoretically could induce a bronchospasm especially in those
patients with known reactive airways. Morphine and meperidine are opioids that induce
histamine release. This reaction is not seen with the synthetic opioids such as fentanyl and
alfentanil. Sodium thiopental also is known to cause histamine release, but despite this has
been used safely even in asthmatics.
Many nondepolarizing agents have been know to cause histamine release including
mivacurium, atracurium and d-tubocurarine. Cis-atracurium is an isomer of atracurium, but
unlike atracurium, does not cause the release of histamine.
1. Miller R. Anesthesia. 5th edition. Churchill Livingstone. New York NY. 2000:451-452. 73. E Pulmonary edema This is a classic presentation of negative pressure pulmonary edema. Negative pressure
pulmonary edema is most often a complication of an acute airway obstruction. The edema
occurs because mark negative intrapleural pressure is generated against a closed or
obstructed glottis driving fluid from the capillary to interstitial tissue. Negative pressure
pulmonary edema most commonly occurs after an episode of laryngospasm and requires
the continued ventilatory effort by the patient. Young athletic male are at increase risk for
developing pulmonary edema since they can generate mark negative intrapleural pressure.
Symptoms such as dyspnea, cyanosis and pink, frothy secretions can appear rapidly. Most
cases require only supportive care and resolve within 12 to 24 hours.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
135
Differential diagnoses include fluid overload and volume overload, both of which can
present with symptoms similar to that above. Intubation of the esophagus will present with
continuing desaturation.
1. Gravenstein N, Kirby RR. Complications in Anesthesiology. 2nd edition. Lippincott. Philadelphia. 1996:191-196. 74. B Venous air embolus Correction of spinal scoliosis provides a challenge to the anesthesiologist. This surgical
procedure involves a patent with pre-existing pulmonary and cardiac dysfunction, placing
the patient in the prone position, the possibility of significant blood loss and an increase
risk of venous air embolus (VAE). The large incisional exposure of bone and tissue increase
this risk of VAE. Sign and symptoms include sudden drop in end-tidal carbon dioxide,
hypotension, hypoxemia, and in severe cases cardiac collapse. A central venous catheter
should be placed to aspirate air should a VAE occur.
Spinal cord ischemia and malignant hyperthermia would not result in a decrease in end
tidal carbon dioxide. The amount of sevoflurane being used would not cause the significant
drop seen in the capnography.
1. Barash P, Cullen B, Stoelting R. Clinical Anesthesia, 4th edition, J.B. Lippincott. Philadelphia. 2001:1110-1111. 75. E Transient neurologic syndrome The term TNS (Transient Neurologic Syndrome) is used to describe symptoms of backache
with radiation into the buttocks or lower extremities. (An earlier used term was Transient
Radicular Irritation but that has been abandoned for TNS.) This syndrome is rarely seen
after general anesthesia and has been associated with central neuraxial anesthesia with all
local anesthetics, particularly lidocaine.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
136
Risk of TNS is increased with use of lidocaine, ambulatory anesthesia, lithotomy and knee
arthroscopy positions, obesity, and is unaffected by baricity, dose, type of needle, addition
of epinephrine, paresthesia, or concentration (no lower incidence with concentrations to
0.5%). TNS typically occurs 12-36 hours after resolution of spinal anesthesia and last for 2-
3 days. TNS is self limited and can be effectively treated with potent nonsteroidal anti-
inflammatory drugs.
Although femoral and obturator neuropathies are complications of lithotomy positioning,
the sensory deficit distribution does not involve the buttocks. Epidural hematoma usually
present with paralysis without sensory changes. Cauda equina syndrome is associated with
sensory and motor deficits but not with TNS.
1. Barash P, Cullen B, Stoelting R. Clinical Anesthesia, 4th edition, J.B. Lippincott. Philadelphia. 2001:709. 2. Spencer SL, et. Al. Current Issues in Spinal Anesthesia, Review Article. Anesthesiology. 2001:94:888-906. 76. B Medullary portion of ascending loop of Henle Mannitol is an osmotic diuretic often used for prophylaxis against acute renal failure and
treatment of increased intracranial pressure. It‘s primary site of action is at the medullary
portion of the ascending loop of Henle. Loop diuretics also exert their effects at this portion
of the tubules. Thiazide diuretic site of action is the cortical portion of the ascending loop of
Henle. The distal convoluted tubule is where potassium sparing diuretic (triamterene) has
their action. Aldosterone antagonists exert their effects at the collecting duct.
1. Stoelting, RK. Pharmacology and Physiology in Anesthetic Practice. 3rd edition. Lippincott-Raven. Philadelphia.1999:436,440-441.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
137
77. C Redistribution into skeletal muscle When an induction dose is given intravenously, it rapidly leaves the blood compartment
and enters the brain where it exerts its hypnotic effects. Uptake into the brain occurs within
30 seconds and peaks at about 5 minutes. After this initial peak in the brain, the drug
begins to redistribute into skeletal muscle. It is this redistribution of sodium thiopental from
the brain into skeletal muscle that accounts for the rapid awakening seen with its use.
1. Stoelting, RK. Pharmacology and Physiology in Anesthetic Practice. 3rd edition. Lippincott-Raven. Philadelphia.1999:436,114-115. 78. D Greater cornu of the hyoid cartilage The superior laryngeal nerve provides sensory to the area from the epiglottis to the vocal
cords (“sensation above the cord”). The nerve a branch from the vagus nerve pierces the
thyrohyoid membrane at the point of the hyoid cartilage. Bilateral blockade is necessary to
block sensation to this area.
The Chassaignac tubercle (the anterior tubercle of the transverse process of C6) is a
landmark used to perform a stellate ganglion block, while the tonsillar pillars represent the
landmarks for a glossopharyngeal block. In order to perform a translaryngeal block, the
cricothyroid membrane must be identified.
1. Miller R. Anesthesia. 5th edition. Churchill Livingstone. New York NY. 2000:1541-1543. 79. E Redistribution of core temperature The hypothalamus tightly controls the core temperature and maintains this within an inter
threshold range of 0.4o C of it set point of 37o C. When temperatures rise above this
threshold, warm autonomic responses (vasodilatation and sweating) occur while
temperatures below this inter threshold range elicit cold autonomic responses
(vasoconstriction, and shivering). Hypothermia is common during anesthesia due to
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
138
anesthetic induced inhibition of these thermoregulatory mechanisms and the patient
exposure to a cold operating room environment.
Intraoperative hypothermia occurs in three phases. The first phase, which begins shortly
after induction and continues for 1 to 2 hours, is due to the internal redistribution of core
temperature to the periphery because of anesthetic induced peripheral vasodilatation.
During the second phase a thermal imbalance occurs because of a reduction in heat
production and loss to the environment. Radiation and convection contribute 85% of the
heat losses occurring in the operating room. Evaporation losses from the skin, respiratory
tract and open surgical wounds contribute 5 to 10% of all heat loss while conductive heat
transfer is often minimal.
The third phase is the thermal steady state and represents the equalization of heat
production with environmental heat loss. 1. Miller R. Anesthesia. 5th edition. Churchill Livingstone. New York NY. 2000:1371-1373. 80. A Complex Regional Pain Syndrome I Complex Regional Pain Syndrome I (CRPS I) is the new term replacing reflex sympathetic
dystrophy (RSD) while CRPS II replaces the term for the syndrome causalgia. CRPS I
usually follow a noxious event that does not involve nerve injury or follow a characteristic
peripheral nerve distribution. CRPS II has the same clinical signs and symptoms but the
history is significant for a nerve injury.
CRPS I presents with a triad of sensory, autonomic and motor signs and symptoms.
Sensory symptoms include pain described as burning and aching. Allodynia and
hyperalgesia is often present. Autonomic signs and symptoms almost always include
edema, skin color changes (erythema or cyanotic), and even changes in skin temperature
(higher or lower) when compared to the other limb. Motor signs and symptoms include
muscle weakness, spasm, and decrease range of motion. Other associated signs can
include trophic changes like increase or decrease nail or hair growth.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
139
Fibromyalgia, peripheral neuropathy and Raynaud’s Syndrome do not include many of
these characteristics, especially allodynia, hyperalgesia, or edema.
1. Srinivasa RN, et.al., Complex Regional Pain Syndrome I (Reflex Sympathetic Dystrophy), Anesthesiology, 2002:96:1254-1260. 81. E Osteoporosis Complex Regional Pain Syndrome, Type I (CRPS I) or Reflex Sympathetic Dystrophy is
characterized by constant, severe burning pain most often involving the upper limbs and
follows a noxious events without nerve damage. Three characteristic phases have often
been described and include an acute hyperemic stage (I), dystrophic stage (II) and
atrophic stage (III). Edema, allodynia, hyperalgesia and skin temperature changes are
often seen in all three phases. Osteoporosis is more characteristic with the atrophic (III)
stage of the disease.
1. Raj PP. Pain Medicine - A Comprehensive Review. Mosby. St. Louis. 1996:473-474. 82. E No treatment Phantom limb sensation is experienced by almost everyone who has a limb amputated
and must be distinguished from phantom limb pain. Unlike phantom limb pain, phantom
limb sensation is not painful and therefore does not require treatment. The sensation is
very vivid and often is described as a “limb” occupying the same space as the amputated
limb. Over time the sensation fades.
1. Nikolajsen L, et. al., Phantom Limb Pain, British Journal of Anaesthesia, 2001:87,107-116.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
140
83. D Allodynia Allodynia is pain due to a stimulus that is not normally painful such as the stroke of a
feather. This sensation is very characteristic in reflex sympathetic dystrophy.
Hyperalgesia is an increase response to a stimulus that is normally painful, while
hyperesthesia is an exaggerated pain response to a noxious stimulus such as pressure or
heat. Hypoalgesia is decrease pain to a stimulus that is normally painful, while analgesia is
the absence of pain to a stimulus that is normally painful.
1. Cousins MJ, Bridenbaugh PO. Neural Blockade in Clinical Anesthesia and Management of Pain. 3rd edition. Lippincott. Philadelphia. 1998:701-703. 84. B Celiac plexus block The celiac plexus is the largest of the great plexuses of the sympathetic nervous system.
The cardiac plexus innervates primarily thoracic structures, the celiac plexus innervates
abdominal organs, and the hypogastric plexus supplies pelvic organs. All three contain
visceral afferent and efferent fibers. In addition, they contain parasympathetic fibers that
pass through these ganglia after originating in cranial or sacral areas of the nervous
system.
Celiac block is indicated in patients with pain arising from the abdominal viscera, especially
pancreatic cancer. Relief of pain is almost immediate. Celiac plexus block performed with a
neurolytic agent can provide relief of pain for up to 4 months. The celiac plexus is generally
clustered at the level of the body of L1, posterior to the vena cava on the right, just lateral
to the aorta on the left, and posterior to the pancreas.
1. Warfield, CA, Bajwa, ZH. Principles and Practice of Pain Medicine, 2nd edition, McGraw-Hill. New York NY. 2004:699-703.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
141
85. B Hypotension Hypotension is the most common complication of celiac plexus blockade. It can be reduced
by volume preloaded before performing the blockade. Hypotension along with pain relief is
also reliable signs of a successful celiac plexus block. Another common complication is
diarrhea due to increased peristalsis of the gut produced by the shift in the balance of the
parasympathetic and sympathetic innervations. This may occur within the first 12 hours
after the blockade and may be a source of relief to patients on chronic opioid therapy for
cancer pain. The most serious complication is the development of paralysis from
unrecognized subarachnoid injection of a neurolytic drug. Radiographic confirmation of
needle location is advisable before injection of any neurolytic drug.
1. Barash P, Cullen B, Stoelting R. Clinical Anesthesia, 4th edition, J.B. Lippincott. Philadelphia. 2001:734-735. 86. D Musculocutaneous nerve The brachial plexus is derived from the anterior primary rami of the C-5, C-6, C-7, C-8 and
T-1 nerves. As the nerve roots leave the intervertebral foramina, they converge, forming
trunks, divisions, cords, and then finally terminal nerves.
The axillary approach to the brachial plexus is the most popular because of ease of block,
reliability of hand and forearm anesthesia, and safety. This block is ideally suited for
outpatients. Axillary block is unsuitable for surgical procedures on the upper arm or
shoulder. At the level of the axillary, the musculocutaneous nerve has already left the
brachial plexus and travels within the coracobrachialis muscle. Supplementation of this
nerve is important since it provides sensory to the lateral portion of the forearm.
Supplementation of the axillary nerve is not required since anesthesia of that nerve is not
required for this procedure.
1. Miller R. Anesthesia. 5th edition. Churchill Livingstone. New York NY. 2000:1524-1527.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
142
87. D Lateral aspect of the forearm The musculocutaneous nerve provides sensation to the lateral aspect of the forearm. The
ulnar nerve provides sensory to the little finger and medial aspect ring finger with medial
aspect of the hand. The median nerve supplies sensory to the lateral part of the palm, the
thenar eminence, thumb, index and middle finger and the lateral half of the ring finger.
The medial cutaneous nerve provides sensory to the medial aspect of the forearm.
The musculocutaneous nerve is often spared after a block of the brachial plexus via an
axillary approach. Its supplementation is therefore important to facilitate surgery involving
the distal portions of the arm. Supplementation involved identifying the coracobrachialis
muscle and injecting local anesthetic into the body of the muscle.
1. Miller R. Anesthesia. 5th edition. Churchill Livingstone. New York NY. 2000:1524-1527 88. A Unilateral recurrent laryngeal nerve injury Recurrent laryngeal nerve injury continues to be one of the most common complications of
thyroid surgery. Unilateral recurrent laryngeal nerve causes hoarseness but no airway
compromise. The affects vocal cord is usually in the paramedian position. Bilateral
recurrent laryngeal nerve results in inspiratory stridor and airway compromise. Both vocal
cords are in the paramedian position. Unilateral vagal nerve injury (i.e., unilateral superior
laryngeal nerve and recurrent laryngeal nerve injury) leads to affected cord being
motionless and bowed in the lateral position. There is no airway compromise.
Unilateral superior laryngeal nerve injury causes the affected cord to appear shorter and
the voice is hoarse. Bilateral superior laryngeal nerve injury causes both cords to shorten
and the voice is also hoarse. Neither results in airway compromise.
1. Gravenstein N, Kirby RR. Complications in Anesthesiology. 2nd edition. Lippincott. Philadelphia. 1996:380.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
143
89. C Amitriptyline The pain associated with acute zoster and postherpetic neuralgia is neuropathic and results
from injury of the peripheral nerves and altered central nervous system signal processing.
Aspirin and other mild analgesic drugs are commonly used in patients with postherpetic
neuralgia, but their value is limited. Ibuprofen is ineffective. Neuropathic pain is also less
responsive to opioids such as morphine. Topical formulation of aspirin and lidocaine has
shown varied results, but are occasionally used.
Tricyclic antidepressant drugs are the most effective therapy for postherpetic neuralgia. Be-
cause of their ability to block the reuptake of norepinephrine and serotonin, these drugs
may relieve pain by increasing the inhibition of spinal neurons involved in pain perception.
They are especially effective for neuropathic pain.
1. Kost RG, et. al., Postherpetic Neuralgia - Pathogenesis, Treatment, and Prevention, New England Journal of Medicine, 1996; 335(1):32-42. 90. D ASA physical status II-E Assignment of physical status is based on the physical condition of the patient and is
independent of the planned operation. It is important to recognize that physical status
classification does not represent anesthetic risk. However, perioperative complications are
more frequent in patient with poor physical status.
Physical Status Classification Description
I A normal healthy patient.
II A patient with mild systemic disease that results in no functional limitations (Hypertension, diabetes, morbid obesity, extremes of age).
III A patient with severe systemic disease that results in functional limitations (poorly controlled hypertension, diabetes with vascular complications, angina pectoris).
IV A patient with sever systemic disease that is a constant treat to life (congestive heart failure, unstable angina, advanced pulmonary, renal or hepatic dysfunction).
V A moribund patient who is not expected to survive without the operation (ruptured abdominal aneurysm, head injury with elevated ICP).
VI A declared brain dead patient whose organ are being removed for donor purposes.
E EMERGENCY OPERATION 1. Stoelting RK, Miller RD. Basics of Anesthesia. 4th edition. Churchill Livingstone. New York NY. 2000:113-114.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
144
91. A All of the potent inhalational agents depress CMR (Cerebral Metabolic Rate) in a linear fashion All of the potent inhalational agents depress CMR (Cerebral Metabolic Rate) to varying
degrees in a non-linear fashion.
Isoflurane abolishes EEG activity at doses used clinically and can usually be tolerated from
a hemodynamic standpoint. Halothane produces isoelectric EEG only at 4.5%
concentration.
All of the potent agents increase CBF in a dose-dependent manner. Halothane is a very
potent cerebral vasodilator and causes the greatest increase in CBF per MAC multiple. In
human studies, isoflurane produces insignificant or no change in CBF.
1. Ebert TJ, Scmid PG: Inhalational anesthesia. In Barash PG, Cullen BF, Stoelting RK (eds): Clinical Anesthesia. 4th edition. Lippincott Williams & Wilkins, Philadelphia, PA. 2001:390 2. Newberg LA, Milder JH, Michenfelder JD: The cerebral metabolic effect of isoflurane at and above concentrations that suppress critical electric activity. Anesthesiology 1983; 59:23-28 3. Algottson L, Messeter K, Nordstrom CH et al: Cerebral blood flow and oxygen consumption during isoflurane and halothane anesthesia in man. Acta Anaesthesiol Scand 1988;32:15-20 92. B The expiratory time The inspiratory time influences the correlation between the set tidal volume and exhaled
tidal volume, not the expiratory time Gas flow from the anesthesia machine into the
breathing circuit is continuous. During the inspiratory phase of mechanical ventilation, the
ventilator relief valve is closed and the patient receives volume from the bellows as well as
from the flow meters. The factors that influence the correlation between set tidal volume
and exhaled tidal volume include the flow meter settings, the inspiratory time, the
compliance of the breathing circuit, external leakage and the location of the tidal volume
sensor.
1. Andrews JJ, Brockwell RC. Delivery systems for inhaled anesthetics. In Barash PG, Cullen BF, Stoelting RK (eds.). Clinical Anesthesia 4th edition. Lippincott Williams & Wilkins, Philadelphia, PA. 2001:584
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
145
93. E Desflurane and sevoflurane cause dose-dependent increase in the myocardial contractility Halothane is notable for its decrease in cardiac output- an effect that contributes
importantly to its blood pressure lowering effect.
In volunteers, sevoflurane and halothane up to about 1 MAC results in minimal, if any,
changes in steady-state heart rate. In contrast isoflurane at 1 MAC and desflurane at >1
MAC have been associated with increase in heart rate of 10-20%.
There is a new body of literature describing the potential for organ-protective effect
(particularly cardioprotective effects) of the potent inhaled agents. This appears to be
related to a reduced loading of calcium into the myocardial cells during ischemia.
Although volatile anesthetics impair coronary autoregulation to some degree, these agents
do not produce the profound degree of coronary vasodilatation and inhibition of
autoregulation caused by adenosine or dipyridamole. Volatile anesthetics are only weak
coronary vasodilators.
All modern volatile anesthetics, including desflurane and sevoflurane, depress contractile
function in normal myocardium in vitro and in vivo.
1. Pagel PS, Farber NE, Warltier DC. Cardiovascular Pharmacology. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:96-116 2. Ebert TJ, Schmid PG in Inhalation Anesthesia. In Barash PG, Cullen BF, Stoelting RK (eds): Clinical Anesthesia. 4th edition. Lippincott Williams & Wilkins, Philadelphia, PA. 2001:392-398 3. Novalija E, Fujita S, Kampine JP et al: Sevoflurane mimics ischemic preconditionng effects on coronary flow and nitric oxide release in isolated hearts. Anesthesiology 1999;91:701-712 4. Conzen PF, Habazettl H, VollmarB et al: Coronary microcirculation during halothane, enflurane, isoflurane, and adenosine in dogs. Anesthesiology 1992;76:261-70
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
146
94. A Rapid sequence induction should be planned with thiopentone and succinylcholine Anterior mediastinal masses are uncommon. By nature of their anatomical location, they
produce three problems: compression of the heart, compression of the large vessels
(principally the superior vena cava) and compression of the trachea and main bronchus. A
patient can be asymptomatic and yet have airway compression, which only manifests at
induction of anesthesia when voluntary control of the airway is lost. Unexpected and often
total airway obstruction occurs on induction of general anesthesia and conventional
solutions, e.g. tracheostomy will not be helpful because the obstruction is usually
intrathoracic and close to or below the carina.
Preoperative maximal inspiratory and expiratory flow volume curves helps to quantify the
degree of impairment and will also differentiate extrathoracic from intrathoracic
obstruction.
1. Goh MH, Liu XY, Goh YS. Anterior mediastinal masses: an anesthetic challenge. Case report. Anesthesia 1999;54:670-682 95. D An infant’s axis of the vocal folds is perpendicular to the trachea The five major anatomic differences between the neonatal and adult airway are:
1. Tongue- An infant’s tongue is relatively large in proportion to rest of the oral
cavity.
2. Position of larynx- An infant’s larynx is higher in the neck (C3-4) than is an
adult’s.
3. Epiglottis – An adult’s epiglottis is broad, and its axis is parallel to that of the
trachea. An infant’s epiglottis is narrower and angled away from the axis of the
trachea.
4. Vocal folds – An infant’s vocal folds have a lower attachment anteriorly than
posteriorly. (Adult’s axis of the vocal folds is perpendicular to the trachea).
5. Subglottis – The narrowest portion of an infant’s larynx is the cricoid cartilage;
in an adult, it is the rima glottidis.
1. Wheeler M, Cote CJ, Todres ID. Pediatric Airway. In Corte CJ, Tordes ID, Ryan JF, Goudsouzian NG (Eds)A Practice of Anesthesia for Infants and Children. 3rd ED. W.B Saunders, Philadelphia, PA. 2001:79-80
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
147
96. D Is a dual chamber device with two leads VDD, a relatively recent development in pacemaker technology, is a single lead, atrial
sensing ventricular pacemaker. It is capable of pacing the ventricles only but can sense
electrical activity in both the chambers. A VDD pacemaker provides AV synchrony and
provides for a physiological rate increase. Because it senses the atrial activity, it can
increase the rate of ventricular pacing as needed to keep up with an increase in SA node
depolarization. It is not an appropriate pacemaker for a patient with atrial fibrillation or
flutter.
1. Gregorators G, Abraham J, Epstein AE, et al. ACC/AHA guidelines. Update for implantation of cardiac pacemakers and antiarrhythmia devices. Summery article: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/NASPE committee to update the 1998 Pacemaker Guidelines) J Am Coll Cardiol. 2002;40(9): 1703-19. 97. D When cardiac arrhythmias are a concern, atropine may be preferable to glycopyrrolate
In order to block the muscarinic effects of edrophonium and neostigmine, anticholinergic
agents (atropine or glycopyrrolate) are routinely added to these reversal agents. Atropine
induces its vagolytic effect much more rapidly than does glycopyrrolate. Therefore, to
minimize the cardiovascular changes, atropine is better suited with rapidly acting
edrophonium, and glycopyrrolate is better suited with the slower acting neostigmine. When
glycopyrrolate is administered with edrophonium, there may be an initial bradycardia unless
it is administered at least 1 minute earlier. On the other hand, administration of atropine
with neostigmine will induce initial tachycardia. Since arrhythmias may occur,
anticholinesterase should be used with caution in patients with autonomic neuropathy.
When cardiac arrhythmias are a concern, glycopyrrolate may be preferable to atropine, and
should be given with anticholinesterases over 2-5 minutes.
1. Savarese JJ, Caldwell JE, Lien CA, Miller RD. Pharmacology of muscle relaxants and their antagonists. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:469
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
148
98. A 0.10 ml 1;200,000 = 5 µg/ cc
Because 1 in 200,000 = 1 G in 200,000 cc or 1000mg in 200,000 or 1000micg in 200cc
or 5 micg /cc
Therefore in 20 cc you need 100micg.
1: 1000 epinephrine has 1G in 1000cc or 1000mg in 1000cc or 1000 micg in 1 cc
As shown above we need only 100 micg;
Therefore, take 0.1 cc and add that to 20 cc
0.1 cc of 1:1000 epinephrine has 100µg of epinephrine which is diluted in 20 cc to give 5µg
/cc.
1. CB, Strichartz GR. Local Anesthetics In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:509 99. D 0.40 Supplemental oxygen can be administered via the low- and high-flow system to increase
the delivery of oxygen in hypoxemic patient. Inspired oxygen concentrations (FiO2)
achieved with nasal cannula depends upon:
• Flow rate of oxygen (L/min)
• Patient tidal volume
• Inspiratory flow rate
• Breathing frequency
• Volume of nasopharynx
Inhaled oxygen concentration is increased to 4% for each 1 L/min increment of oxygen
delivery. Beyond 6L/min (FiO2 45%) inhaled concentration of oxygen does not increase
because nasopharynx volume is fixed.
1. Stoelting RK, Miller RD. Basics of Anesthesia. 4th edition. Churchill Livingstone. New York, NY. 2000:421.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
149
100. B Change the face mask to nonbreathing mask A simple face mask does not include a valve or oxygen reservoir bag. The minimum
oxygen flow rate should be at least 5L/min to prevent rebreathing of CO2. At oxygen flow
rate of 8L/min, the mask can provide inhaled oxygen concentrations of 60%. The partial
rebreathing face mask is a valveless system with a reservoir bag. With oxygen flow rate of
10L/min the inhaled oxygen concentration can be between 50-65%. The nonbreathing
face mask includes unidirectional valve plus an oxygen reservoir bag. Inhaled
concentrations of oxygen can be increased to 100%. Venturi or air-entrainment mask
entrains large volume of room air to mix with the oxygen flow through the injector. The
resultant mixture of gases has inhaled inspired oxygen between 25-40%.
1. Stoelting RK, Miller RD. basics of Anesthesia. 4th edition. Churchill Livingstone. New York, NY. 2000:422. 101. A Administration of Nitroprusside and Propanolol Pheochromocytoma is a catecholamine – secreting tumor. More than 95% are found in the
abdominal cavity, 10% originate outside adrenal medulla, 10% are malignant, and 10% are
bilateral. The hallmark of pheochromocytoma is paroxysmal hypertension associated with
diaphoresis, headache, tremulousness, palpitation, and weight loss. The triad of
diaphoresis, tachycardia, and headache in a hypertensive patient is highly suggestive of
pheochromocytoma. The mainstay of pharmacologic therapy is alpha blockade with
phenoxybenzamine or prazosin followed by beta blockade with propanolol. In the above
example manipulation of adrenal produced surge of sympathetic activity and release of
catecholamine as evident by an acute increase in blood pressure and PVC’s. The best
treatment is nitroprusside which dilates peripheral vessels and propanolol which blocks the
action of catecholamine.
1. Stoelting RK, Dierdorf SF. Anesthedia and Coexisting Disease 4th edition. Churchill Livingstone, New York, NY. 2002:430-434.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
150
102. B Induction with Volatile Anesthetic is accelerated Ventricular septal defect (VSD) is characterized by a left to right intracardiac shunt that
results in high pulmonary blood flow. High pulmonary flow will accelerate induction with
volatile agents because greater volume of blood entering lung due to added shunt volume
take up anesthetic agents to deliver to systematic circulation. In contrast, the amount of
drug entering the circulation via intravenous route will be diluted thus delaying the
induction. Positive pressure ventilation will decrease L to R shunt due to increase
intrathoracic pressure. A decrease in systematic resistance, leading to hypotension will
decrease L to R shunt because of low shunting pressure; while an increase in systematic
vascular resistance with hypertension will increase L to R shunt because of increase in
shunting pressure on the left side.
1. Stoelting RK, Miller RD. Basics of Anesthesia 4th edition. Churchill Livingstone, New York, NY. 2002: 258. 103. A Thrombocytopenia leading to prolonged bleeding time and decreased plasma concentrations of labile factor V sufficient to prolong prothrombin time If packed red cells are used to replace massive blood loss, then based on simple dilution
after the loss of one blood volume, the percentage of the original coagulation factor levels
and platelets will likely be 30 to 40 percent. Unlike platelets which decline rapidly during
the first 24 hours of storage, labile factor V and VIII decline to levels of 50% after two
weeks of storage and then decrease slowly thereafter. Thus slow massive transfusion will
produce coagulopathy due to platelets and coagulation factors dilution. Symptomatic
hypocalcemia or hyperkalemia will occur if transfusion is sufficiently rapid.
1. Longnecker DE Jr., Tinker JH, Morgan GE. Principle and Practice of Anesthesiology 2nd edition. Mosby, New York, NY. 1998: 935, 2422.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
151
104. A By Increasing PAO2, PaCO2 Increases Impaired oxygen diffusion between capillaries wall and alveolar wall prevents complete
equilibration of alveolar gas with pulmonary capillary blood. Many factors affect diffusion
of oxygen through this barrier. For example increase distance between alveoli and
erythrocytes (such as in pulmonary fibrosis) will decrease (impair) diffusion; high cardiac
output shortens the transit time of the red blood cells through capillaries because of
increase in flow, atelectasis will impair diffusion because of increased diffusion barrier. On
the other hand, increase FiO2 with high PAO2 will increase O2 gradient and facilitate
diffusion; continuous positive airway pressure distends alveoli and facilitates diffusion.
Although multiple factors can affect PaO2, the most effective way of increasing PaO2 is by
increasing PAO2.
1. Marini JJ, Wheeler AP. Critical Care Medicine 2nd edition. Williams & Wilkins, Baltimore. 197:378. 105. B Decrease Cardiac Output A dose – dependent reduction of arterial pressure is due to direct myocardial depression
effects of halothane. Halothane at 2 MAC can decrease blood pressure and cardiac output
by 50%. The hypotensive effects on blood pressure are potentiated due to blunting of
inhibitory responses in the carotid and aortic pressure receptors. Bradycardia or junctional
rhythm may result due to slowing of sinuatrial node conduction. Although volatile
anesthetics do increase ventilation perfusion mismatch, this is less likely based on the
history.
1. Morgan GE Jr., Mikhail MS, Murray MJ, (eds). Clinical Anesthesiology 3rd edition. Lange Medical Books/McGraw Hill Publishing Division, New York, NY, 2000:139-140.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
152
106. D Observe in ICU for 24-hours The post-operative complications of parathyroidectomy include hemorrhage, hematoma,
and damage to recurrent laryngeal nerve. Unilateral damage to recurrent laryngeal nerve
manifests itself as hoarseness. Bilateral damage to recurrent laryngeal nerve causes airway
compromise. Hypoparathyroidism from parathyroidectomy leading to hypocalcemia rarely
manifest itself as early as 1 to 3 hours. Typically hypocalcemia does not appear until 24 to
72 hours post-operatively. Laryngeal muscles are very sensitive to hypocalcemia which is
manifested as laryngospasm and inspiratory stridor.
1. Stoelting RK, Miller RD. Basics of Anesthesia 4th edition. Churchill Livingstone, New York, NY. 2002:312-313. 107. D Primary Hemostasis Defect Hemostasis following trauma or surgery depends on three process: (1) localized spasm due
to local myogenic reflexes and the release of humoral factors from platelets, (2) formation
of a platelet plug (primary hemostasis), and (3) coagulation of blood (secondary
hemostasis). A defect in any of the sites can cause bleeding disorder. Formation of the
platelet plug involves: (1) adhesion, (2) release of platelet granules, and (3) aggregation.
The presence of petechiae suggests thrombocytopenia, functional abnormality of platelets
or defects in the integrity of the vascular walls.
Clotting factor disorders include hemophilia. These patients present with deeper tissue
bleeding. Vitamin K is necessary for synthesis of clotting factor II, VII, IX, and X.
Antiplatelet agents, such as aspirin, inhibit synthesis of thromboxane A2 for life of platelets.
1. Morgan GE Jr., Mikhail MS, Murray MJ, (eds). Clinical Anesthesiology 3rd edition. Lange Medical Books/McGraw Hill Publishing Division, New York, NY, 2000:717.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
153
108. C Antiplatelet Agents Uremia is seen in patients with end-stage renal disease when GFR decreases below 25
ml/min. Uremia produce platelet defect which is due to accumulation of toxic metabolites
that reduce platelet aggregation. Dialysis provides temporary benefit. Desmopressin
(DDAVP) also improves platelet function. Long term alcohol consumption leads to platelet
dysfunction. Antiplatelet agents (aspirin) are the most common cause of platelet
dysfunction. These drugs inhibit synthesis of thromboxane A2. Fibrin degradation products
produced from fibrin, inhibit crosslinking of fibrin strands and coat surface of platelets
which inhibit platelet aggregation. Vitamin K is needed for synthesis of clotting factors II,
VII, IX, and X.
1. Stoelting RK, Miller RD. Basics of Anesthesia. 4th edition. Churchill Livingstone. New York, NY. 2000:244. 109. D All of the above
Aminocaproic acid Tranexamic acid Aprotinin
Conversion of plasminogen to plasmin by plasminogen activator enzymes is responsible for
fibrinolysis. Fibrinolysis leads to the dissolution of fibrin clots and is necessary to restore
normal blood flow in condition such as DIC. DIC stimulates fibrinolysis as a defense
mechanism to lyse blood clots. Aminocaproic (EACA) tranexamic acid (TXA) and aprotinin
are antifibrinolytic. EACA and TXA bind to both plasminogen and plasmin molecules and
prevent plasmin from degrading fibrinogen and fibrin. This leads to reduced lysis and
reduced formation of fibrinogen degradation products. Aprotinin is an inhibitor of plasmin
and kallikrein.
1. Morgan GE Jr., Mikhail MS, Murray MJ, (eds). Clinical Anesthesiology 3rd edition. Lange Medical Books/McGraw Hill Publishing Division, New York, NY, 2000:721.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
154
110. D It is an ungrounded system on the secondary side of transformer Leakage current is present in all electrical equipment as a result of defective insulation,
capacitive coupling or induction between internal electrical circuits. The magnitude of such
leaks is imperceptible (less than 1 mA). However (100 uA) can cause ventricular fibrillation
if it reaches the heart directly. Line isolation monitor is a device that continuously monitors
the integrity of the isolated power system and protects a patient from macro shock not
microshock (100 uA current).
1. Morgan GE, Mikhail MS, Murray MJ (eds.). Clinical Anesthesiology. 3rd edition. Lange Medical Books/McGraw-Hill Medical Publishing Division. New York, NY. 2002:23 111. A External DC cardioversion In the presence of hemodynamically compromised ventricular tachycardia immediate
synchronized DC cardioversion is required. Ventricular tachycardia not associated with
hypotension is best managed by intravenous administration of amiodarone or
procainamide. Ventricular tachycardia is defined as the presence of at least three
consecutive wide QRS complexes on EKG occurring at an effective rate of 120 bpm or
higher. Amiodarone nor a calcium channel blockers or phenylephrine will be an
appropriate choice.
1. Barash PG, Cullen BF, Stoelting RK (eds.). Handbook of Clinical Anesthesia. 4th edition. Lippincott Williams & Wilkins. Baltimore MD. 2001:847. 112. E Low - 20 Dibucaine is a local anesthetic which inhibits normal pseudocholinesterase activity by 80%,
the homozygous atypical enzyme by 20% and heterozygous atypical enzyme by 40-50%.
The enzyme activity is measured in terms of hydrolysis of acetylcholine by
pseudocholinesterase. Dibucaine number is the percentage inhibition of
pseudocholinesterase activity and is proportional to pseudocholinesterase function (normal
or atypical). Thus, the presence of an atypical form of enzyme in circulation will lead to
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
155
prolonged muscle relaxation with succinylcholine because of slow hydrolysis. In this
example, prolonged effect of succinylcholine with inadequate muscle strength after an hour
most likely indicates homozygous atypical enzyme.
1. Morgan GE, Mikhail MS, Murray MJ (eds.). Clinical Anesthesiology. 3rd edition. Lange Medical Books/ McGraw-Hill Medical Publishing Division. New York, NY. 2002:183. 113. C Compression of fetal head Compression of fetal head or stretching of the neck during uterine contractions leads to
uniform deceleration (usually 10 – 40 beats/min.) of fetal heart rate. These are thought to
be mediated via vagus nerve and are not indicative of fetal distress. Since the question
says uniform changes in fetal heart rate during uterine contractions, the best choice is C.
Late or Type II decelerations follow the peak of uterine contractions and begin 10-30
seconds after the onset of the uterine contraction. These decelerations are thought to be
due to the effect of a decrease in arterial oxygen tension and maternal hypotension leading
to uteroplacental insufficiency. These are associated with fetal distress. Variable or Type
III decelerations are variable in onset, duration and magnitude and are thought to be due
to umbilical cord compression. These decelerations are generally benign unless associated
with fetal bradycardia (HR slower than 70 bpm) or prolonged beyond 30 seconds.
1. Morgan GE, Mikhail MS, and Murray MJ, (eds.). Clinical Anesthesiology. 3rd edition. Lange Medical Books/McGraw-Hill Medical Publishing Division. New York, NY. 2002:841. 114. A Heart rate This is a case of autonomic hyperreflexia (AH). Autonomic hyperreflexia should be
expected in patients with spinal cord lesions above T6 levels, which can be precipitated by
surgical manipulations. AH is seen after the resolution of spinal shock and the return of
spinal reflexes 1-3 weeks after injury. In AH, sympathetic nervous system below the level
of spinal cord transection is functionally isolated from inhibitory influences of the brain. Any
cutaneous or visceral stimulus below the level of the lesion produces intense sympathetic
discharge with hypertension and vasoconstriction. A baroreceptor parasympathetic
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
156
mediated compensatory reflex above the lesion produces reflex bradycardia and
vasodilation. Deep general anesthesia and regional anesthesia (spinal) prevents AH.
Changes in heart rate and chronic vasodilation leading to hypothermia are most common in
these patients.
1. Morgan GE, Mikhail MS, Murray MJ, (eds.). Clinical Anesthesiology. 3rd edition. Lange Medical Books/McGraw-Hill Medical Publishing Division. New York , NY. 2002:590. 115. B Increased sensitivity to depolarizing and nondepolarizing muscle relaxants This patient has myasthenic syndrome (Eaton-Lambert syndrome). The syndrome is due to
the presence of antibodies which are directed to presynaptic calcium channels that
markedly reduces the quanta of acetylcholine released from the presynaptic sites. Repeated
efforts, exercise and drugs such as 4-aminopyridine that stimulate the presynaptic release
of acetylcholine improve skeletal muscle strength. There is poor response to
anticholinesterases and increased sensitivity to succinylcholine and nondepolarizing muscle
relaxants. Therefore, muscle relaxants should be used in very small amounts. In general
volatile agents are sufficient to provide muscle relaxation for both intubation and surgical
procedures. Immunosuppressive agents will not affect the muscle strength.
1. Stoelting RK, Dierfdorf SF (eds.). Anesthesia and Coexisting Disease. 4th edition. Churchill Livingstone. New York, NY. 2002:527. 116. A See the patient sometime today for pre-anesthetic evaluation Generally anesthesiologists see the patient prior to the day of scheduled outpatient surgery
unless some unusual circumstances prevent this evaluation. The objective is to perform
history, physical examination, order preoperative tests and assess the suitability for an
outpatient surgery. In this elderly patient it may be appropriate to order preoperative EKG,
CBC and basic electrolytes including BUN, creatinine and glucose to assess the cardiac and
renal functional status (most commonly affected systems in the elderly patients). It is not
necessary to obtain routine radiographs in the absence of positive findings on the history or
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
157
physical examination. There is nothing in history or physical examination to suggest that
an outpatient procedure could be hazardous.
1. Stoelting RK, Miller RD, (eds.). Basics of Anesthesia. 4th edition. Churchill Livingstone. New York, NY. 2002:392-393. 117. E Elderly patients with a history of hypertension and diabetes Age is not a factor in the selection of patients for outpatient surgery. In elderly patients,
acceptability for outpatient surgery is influenced by physical status of the patient, prior
history and the ability to be cared for by a competent adult at home. Patients not likely to
be candidate for outpatient surgeries are: patients with a history of prolonged nausea,
vomiting and pain, or presence of poorly controlled systematic illness; patients prone to
hospital acquired infections, neonates born prematurely and infants with past history of
respiratory distress syndrome or a family history of sudden infant death syndrome.
1. Stoelting RK, Miller RD, (eds.). Basics of Anesthesia. 4th edition. Churchill Livingstone. New York, NY 2002:392-394. 118. B Calcium Hypermagnesemia (>2.5 mg/dl) is generally iatrogenic (treatment of gestational
hypertension). However, it can also occur due to excessive intake (antacid and laxative
abuse), renal impairment, adrenal insufficiency, hypothyroidism, rhabdomyolysis and
lithium administration. Symptomatic hypermagnesemia presents with neurologic,
neuromuscular manifestations consisting of hyporeflexia, sedation, skeletal muscle
weakness, impaired pre-junctional release of acetylcholine and decrease in motor end-plate
sensitivity to acetylcholine. The cardiovascular symptoms of hypermagnesemia consist of
vasodilation, bradycardia, myocardial depression and respiratory arrest (24 mg/dl). For
symptomatic hypermagnesemia, calcium is used to reverse magnesium effects and
mechanical ventilatory support is continued until the effects dissipate.
1. Stoelting RK, miller RD, (eds.). Basics of Anesthesia. 4th edition. Churchill Livingstone. New York, NY. 2002: 236.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
158
119. D Administer oxygen and intravenous calcium gluconate Hypoparathyroidism from unintentional removal of the parathyroid glands can cause acute
hypocalcemia. A decrease in plasma calcium concentration (less than 4.5 mEq/L) is the
most diagnostic indicator of hypoparathyroidism. This is manifested with muscle cramps,
weakness, increased neuromuscular irritability, changes in mental status, hypotension and
EKG changes (prolonged QT interval). Symptoms of hypocalcemia generally develop in 24-
48 hours after surgery. Other possible complications of thyroidectomy include recurrent
laryngeal nerve palsy with unilateral palsy causes hoarseness or aphonia, and bilateral
palsy resulting in stridor. The history and physical examination of this patient strongly
suggests hypocalcemia (multisystem symptoms) which should be treated with intravenous
administration of 10% CaCl2 (3-5 ml) or calcium gluconate solution (10 ml).
1. Morgan GE, Mikhail MS, and Murray MJ, (eds.). Clinical Anesthesiology. 3rd edition. Lange Medical Books/McGraw-Hill Medical Publishing Division. New York, NY. 2002: 742-744. 120. C His physiologic dead space is 300 ml due to increase in V/Q mismatch Physiologic dead space is composed of anatomical dead space as well as alveolar dead
space (that is alveoli that are not perfused). In the upright position dead space is about
150 ml in adults. Physiologic dead space increases during general anesthesia due to
increase in V/Q mismatch. Use Bohr’s equation to calculate dead space.
VD/VT = (PACO2 – PECO2) / PACO2
Where PACO2 is alveolar CO2 tension and PECO2 is the mixed expired CO2 tension. The
arterial CO2 tension (PaCO2) can be used to approximate the alveolar concentration.
1. Morgan GE, Mikhail MS, and Murray MJ, (eds.). Clinical Anesthesia. 3rd edition. Lange Medical Books/McGraw-Hill. New York, NY. 2002:490.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
159
121. D The difference between diastolic arterial and pulmonary wedge pressures The main determinants of coronary perfusion pressure are aortic diastolic pressure (DP)
and left ventricular end-diastolic pressure (LVEDP). Wedge pressure is measured to
evaluate the preloading conditions of the left ventricle which correlates with left ventricular
end-diastolic pressure (LVEDP). This wedge pressure should be measured at the end of
left ventricular diastole. On venous pressure tracing this corresponds to the end of A-wave
before the appearance of C-wave, taken at end expiration. Therefore in the question
asked, D is the most appropriate choice. Central venous pressure is used as an index of
right ventricular preload, although it may approximate left ventricular preload in most
normal individuals. Therefore, choice B will be the second most plausible choice.
Endocardium is most vulnerable to ischemia because it is subject to greatest intramural
pressure. Any pathophysiology which will change DP (hypertension, ventricular
hypertrophy, tachycardia with decrease in filling volume and pressure) and LVEDP (left
ventricular hypertrophy, changes in compliance) will affect the subendocardial perfusion
pressure.
1. Morgan GE, Mikhail MS, and Murray MJ, (eds.). Clinical Anesthesiology. 3rd edition. Lange Medical Books/ McGraw-Hill Medical Publishing Division. New York, NY. 2002: 376. 122. C Administer 2 mg edrophonium intravenously and recheck MIF This patient is 2 hours post-surgery. Continued muscle weakness as evident from high
PC02, low MIF strongly suggests weakness due to myasthenia gravis and not to the
continued presence of muscle relaxant (rocuronium). Although, myasthenic patients are
more sensitive to nondepolarizing muscle relaxants, > 25% of twitch response returns back
in 25 minutes following administration of rocuronium. Of the two choices B and C, choice
C is the most plausible choice. Edrophonium is a short acting anticholinesterase and
intravenous administration of this drug should produce transient improvement in muscle
strength. Neuromuscular blockade should be monitored with a nerve stimulator before
administration of edrophonium. This will help in understanding the etiology of continued
weakness of this patient and make additional plans for management (such as continued
ventilation or treatment with neostigmine). A peak inspiratory pressure of –20 cm H2O,
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
160
adequate oxygenation, sustained head lift and vital capacity > 15 ml/kg, is crucial before
extubation.
1. Morgan GE, Mikhail MS, and Murray MJ (eds.). Clinical Anesthesiology. 3rd edition. Lange Medical Books/McGraw-Hill Medical Publishing Division. New York, NY. 2002: 754. 123. C Administration of recombinant factor VIII to increase factor VIII to 50% normal The most common inherited defect in secondary hemostasis is factor VIII deficiency. It is
inherited as x-linked abnormality. Patients with less than 5% of normal factor VIII activity
are symptomatic. Most clinicians recommend factor VIII levels to be 50% or greater prior
to surgery. Although fresh frozen plasma, cryoprecipitate can be used to replace factor
VIII deficiency, recombinant factor VIII is currently favored in order to avoid transmission
of hepatitis B or C, and HIV.
1. Morgan GE, Mikhail MS, and Murray MJ, (eds.). Clinical Anesthesiology. 3rd edition. Lange Medical Books/McGraw-Hill Publishing Division. New York, NY. 2002:722. 124. B Endotracheal intubation as soon as possible This is a case of a burn patient with possible inhalational injury. Singed eyebrows,
eyelashes or black soot around the nose should increase the suspicion of upper and lower
airway injury. The first priority in the management of these patients is administration of the
highest possible concentration of oxygen by a face mask. Early intubation is indicated if the
airway reflexes are depressed or there is suspicion of impending airway obstruction. Airway
humidification, bronchial toilet and the use of bronchodilator, if needed, is indicated. A
high FiO2 improves oxygenation and promotes elimination of carboxyhemoglobin. Normal
oxygen saturation from a pulse oximeter does not exclude the possibility of carbon
monoxide toxicity.
1. Morgan GE, Mikhail MS, Murray MJ, (eds). Clinical Anesthesiology. 3rd edition. Lange Medical Books/ McGraw-Hill Medical Publishing Division. New York, NY. 2002:801-803.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
161
125. A Physostigmine, scopolamine, carbon dioxide Physostigmine, neostigmine and edrophonium are cholinesterases. Edrophonium and
neostigmine have quaternary ammonium group which bind to the anionic site of
acetylcholinesterase. Physostigmine is a tertiary amine which crosses the blood-brain-
barrier. This limits its usefulness as a reversal agent for nondepolarizing blockade. Atropine,
scopolamine and glycopyrrolate are anticholinergics. Glycopyrrolate is a synthetics
quaternary ammonium containing compound and in contrast to scopolamine and atropine
does not cross the blood-brain-barrier. Scopolamine has greater CNS effects than atropine.
Since bicarbonate is a negatively charged molecule it can not cross blood-brain-barrier.
However it can combine with a proton to form carbonic acid which dissociates into carbon
dioxide and water. Carbon dioxide can diffuse freely through the blood-brain-barrier,
reform carbonic acid which then dissociates into bicarbonate and hydrogen ion.
1. Morgan GE, Mikhail MS, Murray MJ, (eds.). Clinical Anesthesiology. 3rd edition. Lange Medical Books/McGraw-Hill Publishing Division. New York, NY. 2002:210. 126. A Hyperkalemia Spironolactone is a K- sparing diuretic. It is a competitive inhibitor of aldosterone. It often
is co-administered with thiazide or loop diuretics in the treatment of hypertension and
edema. These combinations result in increased mobilization of edema fluid with fewer
changes in the redistribution of K ions. Spironolactone is also used in the treatment of
primary hyperaldosteronism, refractory edema associated with ascites, cirrhosis, cardiac
failure, nephritic syndrome. Its side effects include: hyperkalemia, metabolic acidosis in
cirrhotic patients, impotence, gynecomastia, hirsutism and menstrual irregularities.
Spironolactone does not produce hypercalcemia, hypoglycemia or hyperglycemia, although
it may produce hyponatremia.
1. Morgan GE, Mikhail MS, Murray MJ, (eds.) Clinical Anesthesiology. 3rd edition. Lange Medical Books/McGraw-Hill Publishing Division. New York, NY. 2002:676.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
162
127. A Intestinal obstruction, tremor and hepatic dysfunction Metoclopramide is a substituted benzamide which block D2 dopamine receptors and 5-HT3
receptors at higher concentrations. It enhances gastric emptying and transit of intestinal
contents from the duodenum to the ileocecal valve through action on smooth muscles of GI
wall. Therefore it is contraindicated in patients with intestinal obstruction. The
bioavailability is only 75% after oral administration due to hepatic first pass metabolism
(therefore not a desirable drug in patients with hepatic dysfunction). Because of its
antagonism at D2-dopamine receptors, its use is contraindicated in patients with
Parkinsonism. Other effects of metoclopramide include: increase lower gastroesophageal
tone, drowsiness, dizziness, depression (crosses BBB). It has no effect on gastric secretions
or colonic motility. It is useful as antiemetic agent in emesis during cancer therapy and
pregnancy. Doses of digoxin and insulin may need adjustment if metoclopramide is given
orally.
1. Hardman JG, Limbird LE, Molinoff PB, Ruddon RW, Gilman AG, (eds.). The Pharmacological basis of Therapeutics. 9th edition. McGraw-Hill. New York, NY. 1996:933. 128. B Maximum mid expiratory flow (MMEF) Spirometry provides useful information of expired volumes. For nonpulmonary surgery, it
rarely provides additional information which can not be obtained from history and physical
examination. Maximum breathing capacity (MBC), or maximum voluntary ventilation (MVV),
forced expiratory volume in one second, negative inspiratory pressure and peak inspiratory
flow rate, are all effort dependent and require patient’s motivation and cooperation. A low
value in these parameters may suggest poor functional capacity but in reality may only
reflect suboptimal effort. Maximal mid-expiratory flow and forced expiratory flow reflect
effort independent parameters. A decreased mid-expiratory-flow rate reflects collapse of
the small airways and is a sensitive indicator of early airway obstruction. Therefore, of the
choices given, choice B is the most appropriate choice.
1. Duke James, (eds.). Anesthesia Secrets. 2nd edition. Hanley and Belfus, Inc. Philadelphia, PA. 2000:431. 2. Barash PG, Cullen BF, Stoelting RK, (eds.). Clinical Anesthesia. 4th edition. Lippincott Williams & Wilkins. Philadelphia, PA. 2001:814.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
163
129. A Airway suctioning, intubation, mechanical ventilation with PEEP and observation in ICU This is a case of gastric aspiration. The most appropriate course of action would be airway
suction, intubation and mechanical ventilation especially in view of the fact that the patient
is desaturating. Trachea is suctioned before positive pressure ventilation. This avoids
disseminating aspirated material into distal airways. In the presence of hypoxemia,
increased airway resistance and pulmonary edema, the patient is ventilated with
supplemental oxygen, peep or CPAP. Use of steroids or prophylactic antibiotics use is not
recommended. If evidence of bacterial infection appears, antibiotics therapy should be
based on Gram stain and culture of sputum. Prophylactic use of antibiotics is not
recommended. Saline lavage is also not recommended. However bronchoscopy may be
necessary to relieve airway obstruction caused by inhaled food particles. .
1. Barash PG, Cullen BF, Stoelting RK, (eds.). Clinical Anesthesia. 4th edition. Lippincott and Wilkins. Philadelphia, PA. 2001:1392. 130. C Deepen the level of anesthesia with volatile anesthetic This is a case of foreign body aspiration in a pediatric patient. The foreign body may be
irritating or nonirritating to the airways. It should be removed within 24 hours as it may
cause residual pulmonary disease or pneumonia. Induction of anesthesia is individualized in
each case. Anesthesia is induced and maintained with volatile anesthetic agents in
spontaneously breathing patient. After an adequate depth of anesthesia direct
laryngoscopy is performed. However, if the patient has recently eaten, full stomach
precaution should be taken and anesthesia is induced intravenously by rapid sequence
induction and cricoid pressure. Use of nitrous oxide should be avoided to reduce airway
trapping distal to obstruction. In this particular patient, deepening of anesthesia with
sevoflurane will relax tracheal muscle. One can administer nebulized albuterol or
intravenous bronchodilator to relieve bronchospasm. Alternatively, skeletal muscle
paralysis produced with succinylcholine may be required to remove the foreign body
through the vocal cords.
1. Barash PG, Cullen BF, Stoelting RK, (eds.) Clinical Anesthesia. 4th edition. Lippincott and Wilkins. Philadelphia, PA. 2001:996.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
164
131. B Cancel the surgery and monitor the child Masseter muscle spasm (MMR) or trismus is a forceful contraction of jaw that prevents full
mouth opening. MMR occurs in 15 – 30% of the patients susceptible to malignant
hyperthermia (MH). Since the above surgery is an elective surgery, the safest course is to
postpone the surgery and observe the patient for signs and symptoms of MH. Serum
creatine kinase (CK) levels should be followed for 24 hours after an episode of MH. This is
not a sensitive test but elevation of CK indicates an underlying myopathy. The most reliable
test to diagnose MH is halothane-caffeine contracture test. Some anesthesiologist may
switch to non-triggering anesthetic agents for the maintenance of anesthesia and allow the
surgery to continue so long as no other signs of malignant hyperthermia develop.
Dantrolene administration is recommended only when there is a clear diagnosis of MH.
1. Morgan GE, Mikhail MS, Murray MJ, (eds.) Clinical Anesthesiology. 3rd edition. Lange Medical Books/ McGraw Hill Publishing Division, New York, NY. 2002:869. 132. A Topical anesthesia of airway followed by awake oral intubation with in line stabilization of the neck This is a post-trauma patient. Because of the emergent nature of the surgery the details of
the injuries are unknown. The most appropriate choice is A which is least traumatic to the
patient. Immobilization of the neck in the neutral position is indicated in unconscious or
conscious patients with cervical pain or tenderness. Nasotracheal intubation caries risk of
epistaxis and possible entry of the endotracheal tube into the cranial vault if there is
damage to cranial base or maxillofacial complex. LeFort 1 fracture involves the maxilla and
the maxillary sinus. LeFort 2 and 3 fractures involve the thick portion of the nasal septum.
In LeFort 2 fracture extends to the medial side of the orbit whereas LeFort 3 fracture
involves the orbit laterally and extends towards the temporal bone.
1. Barash PG, Cullen BF, Stoelting RK, (eds.) Clinical Anesthesia. 4th edition. Lippincott and Wilkins. Philadelphia, PA. 2001:1256-1260.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
165
133. A Diffusion barrier to oxygen The main features of ARDS are:
• diminished lung compliance
• refractory hypoxemia
• diffuse radiographic changes in lungs
• low or normal pulmonary capillary wedge pressure
• pulmonary edema
Hypoxemia is the result of right to left shunting of blood through collapsed or fluid filled
alveoli. Mechanical ventilatory support with PEEP is required to maintain adequate
oxygenation. The most significant improvement after recovery from ARDS is improvement
in oxygenation.
1. Barash PG, Cullen BF, Stoelting RK, (eds.). Clinical Anesthesia. 4th edition. Lippincott and Wilkins. Philadelphia, PA. 2001:1468. 134. C Cardioversion Severe narrowing of aortic valve results in chronic obstruction to left ventricular ejection
which leads to increased intraventricular systolic pressure and concentric ventricular
hypertrophy. This ultimately leads to decrease in ventricular contractility and stroke
volume. Because the ventricle is so stiff, atrial contraction is critical for maintaining
ventricular filling and stroke volume. This “atrial kick” may account up to 30-40% of left
ventricular end-diastolic volume. The enlarged muscle mass increases myocardial oxygen
requirement and myocardium may be susceptible to ischemia even in the absence of
coronary artery disease. This patient is post-aortic valve replacement. The pathophysiologic
changes in the heart muscle induced from stenosed aortic valve still exist. Atrial fibrillation
with tachycardia reduces ventricular filling and stroke volume even further resulting in
hypotension and reduced coronary perfusion. This leads to cardiac ischemia and congestive
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
166
heart failure. The most appropriate immediate first step in the management of this patient
is conversion to sinus rhythm and reduction of the heart rate through cardioversion.
1. Morgan GE, Mikhail MS, Murray MJ, (eds.). Clinical Anesthesia. 3rd edition. McGraw-Hill New York, NY. 416-417. 135. B Administer nitroprusside Topical conjunctival application of phenylephrine produces papillary dilation and capillary
congestion. Systemic effects such as hypertension, headache, tachycardia and
tremulousness may occur. This is particularly important in patients with coronary artery
disease who may develop severe myocardial ischemia, cardiac dysrhythmias and
myocardial infarction. Phenylephrine is a pure alpha-agonist which increases venous
contraction more than arterial contraction, increases preload and to some extent afterload
as well. The net effect is increase in blood pressure and coronary flow. Lidocaine will not
antagonize the effects of phenylephrine. Propanolol is a beta blocking agent, which will
make the bradycardia worst. Atropine and glycopyrrolate because of antimuscarinic effects
will increase the heart rate but will have no effect on peripheral resistance. Therefore, the
most appropriate choice is B. Nitroprusside acts on smooth muscle, causes dilation of
arterial and venous vessels and decreases pre- and afterload. Normalization of blood
pressure will inhibit reflex bradycardia.
1. Barash PG, Cullen BF, Stoelting RK, (eds.). Clinical Anesthesia. 4th edition. Lippincott and Wilkins. Philadelphia, PA. 2001: 296, 975.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
167
136. C PaCO2 Cerebral blood flow is dependent upon cerebral perfusion pressure, respiratory gases
tension especially PaCO2, temperature, viscosity and autonomic influences. Cerebral
perfusion pressure is autoregulated between 50 – 150 mmHg. The most important factor
controlling blood flow to ischemic brain tissue is PaCO2. Increasing CO2 causes vasodilation
and increased blood flow to nonischemic areas because the focal ischemic areas are
already maximally dilated due to the metabolic demands of the ischemic tissue. Thus a high
PaCO2 would shunt blood to areas of less demand. Reducing blood CO2 with
hyperventilation or reducing (CMRO2) would reduce blood flow to most areas of brain due
to vasoconstriction and increase blood flow to the vessels supplying the ischemic areas.
This phenomena “inverse steal or Robin Hood effect” would have the effect of maximizing
blood flow to compromised areas.
1. Barash PG, Cullen BF, Stoelting RK, (eds.). Clinical Anesthesia. 4th edition. Lippincott and Wilkins. Philadelphia, PA. 2001:746. 137. C Increased drug metabolism and increased isoflurane MAC Hypothermia is defined as a body temperature of less than 36° C. Hypothermia has a
protective effect on cerebral and cardiac ischemia due to a reduction in metabolic oxygen
requirement. Hypothermia also decreases drug metabolism, the MAC of all the volatile
anesthetics. Therefore, choice C is incorrect. The deleterious effects of hypothermia
include:
• Cardiac dysrhythmias
• Increased peripheral vascular resistance
• Coagulopathy
• Altered mental status
• Increased stress response and increased protein catabolism
1. Morgan GE, Mikhail MS, Murray MJ, (eds.). Clinical Anesthesiology. 3rd edition. Lange Medical Books/McGraw-Hill Medical Publishing Division. New York, NY. 2002:117.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
168
138. A An 80-year-old man with a history of coronary artery disease, profoundly hypotensive scheduled for emergency surgery for ruptured appendix Ketamine one of the inducing agents used for general anesthesia. It produces a dissociative
anesthesia, that is, it dissociates the sensory inputs from the thalamus to the limbic system.
Its half life is 10 – 15 minutes due to rapid redistribution. Ketamine increases arterial blood
pressure, heart rate and cardiac output due to central stimulation of sympathetic nervous
system and inhibition of reuptake of norepinephrine. It also causes an increase in
pulmonary artery pressure. For these reasons ketamine should be avoided in patients with
coronary artery disease, congestive heart failure or severe hypertension. In severely
hypotensive patients (i.e., shock) ketamine should be avoided because these patients have
depleted stores of catecholamine and ketamine itself has cardio-depressant effect.
Ketamine is a useful inducing agent for asthmatic patients (because of its bronchodilation
effects) and in patients with cardiac tamponade. It is contraindicated in patients with
increased ICP because it increases cerebral oxygen consumption and intracranial pressure.
1. Morgan GE, Mikhail MS, Murray MJ, (eds.). Clinical Anesthesiology. 3rd edition. Lange Medical Books/McGraw-Hill Medical Publishing Division. New York, NY. 2002:171. 139. E All of the above
Pentazocine Nalbuphine Buprenorphine Naloxone
Pentazocine acts as a weak antagonist or partial agonist at mu opioid receptors.
Pentazocine does not antagonize the respiratory depressant effects of morphine. However,
it may precipitate withdrawal when given to patients dependent on morphine or heroin.
High doses of pentazocine itself may cause respiratory depression with associated
increased blood pressure and tachycardia.
Nalbuphine is a mixed opioid i.e., it is an agonist-antagonist opioid. The antagonist effect of
nalbuphine is speculated to occur at mu receptors. This antagonist property at mu-
receptors can be used to reverse ventilatory depressant effects of opioids agonists while
still maintaining analgesia. Buprenorphine is a mixed opioid with agonist and antagonist
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
169
properties. It has high analgesic properties. However, because of antagonism at mu-
receptors it can cause an acute withdrawal in patients addicted to heroin and morphine.
Naloxone is a pure antagonist and can precipitate acute withdrawal in heroin addicted
individuals. 1. Stoelting RK, (eds.) Pharmacology and Physiology in Anesthetic Practice. 3rd edition. J.B. Lippincott Company. Philadelphia, PA. 1999:104. 140. A Hyperkalemia and Verapamil toxicity Calcium is no better than placebo in promoting resuscitation and survival from asystole and
pulseless electrical activity. Calcium is not recommended during CPR unless specific
indications exist. It should be infused slowly because rapid infusion can produce cardiac
arrhythmias. Calcium is useful if hyperkalemia, symptomatic hypocalcemia or calcium
channel blocker toxicity is present. For administration calcium chloride is recommended
because it produces higher and more consistent levels of ionized calcium levels. Calcium is
not used for digoxin or tricyclic antidepressant toxicity. 1. Barash PG, Cullen BF, Stoelting RK, (eds.). Clinical Anesthesia. 4th edition. Lippincott and Wilkins. Philadelphia, PA. 2001:1500. 141. A Ketorolac has little potential for renal toxicity when fluid balance is adequate Ketorolac is a member of NSAID group with significant analgesic effects. Ketorolac 30 mg
IM produces analgesia that is equivalent to 10 mg of morphine and 100 mg of meperidine.
It is renal toxic in patients with hypovolemia, congestive heart failure or hepatic cirrhosis
who depend upon prostaglandins for preventing renal arteriolar constriction. It inhibits
platelet aggregation by inhibiting platelet cyclooxygenase activity. It produces its
antipyretic and antiinflammatory effects by inhibiting prostaglandin synthetase. 60% is
excreted unchanged in urine while the rest 40% is conjugated with glucuronide.
1. Stoelting RK, (eds.) Pharmacology and Physiology in Anesthetic Practice. 3rd edition. J.B. Lippincott. Philadelphia, PA. 1999:255-256.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
170
142. A Three times more potent than diazepam Midazolam is water-soluble and almost three times as potent as diazepam. The onset is
0.9-5 minutes. It is rapidly metabolized in liver. Hepatic clearance of midazolam is 10 times
that of diazepam (i.e., has significantly shorter half time). The volume of distribution and
lipid solubility of both the drugs are similar. Midazolam produces respiratory depression
similar to that of diazepam but a greater decrease in blood pressure and an increase in
heart rate than diazepam. Diazepam is water-insoluble. Therefore, it is dissolved in
propylene-glycol. Unlike midazolam IM injection of diazepam is painful.
1. Stoelting RK (eds.). Pharmacology and Physiology in Anesthetic Practice. 3rd edition. J.B. Lippincott. Philadelphia, PA. 1999: 130-132. 143. B Increased muscle weakness Most common cause of hypophosphatemia in an ICU patient is inadequate phosphorus
supplementation during hyperalimentation. Other causes include: diabetic ketoacidosis,
alcohol abuse, prolonged respiratory alkalosis and abuse of aluminum or magnesium
containing antacids. Severe hypophosphatemia is associated with wide spread organ
dysfunction, such as: cardiomyopathy, hemolysis, impaired leukocyte function, skeletal
muscle weakness and myopathy, rhabdomyolysis, respiratory failure and hepatic
dysfunction. During anesthesia neuromuscular function must be monitored and respiratory
alkalosis and hyperglycemia should be avoided. 1. Morgan GE, Mikhail MS, Murray MJ, (eds.) Clinical Anesthesiology. 3rd edition. Lange Medical Books/McGraw-Hill Publishing Division. New York, NY. 2002:622. 144. A Upper airway obstruction and carbon dioxide retention Pickwickian syndrome include: obesity hypoventilation syndrome due to decreased
ventilatory response to CO2 and oxygen resulting in sleep apnea, hypoxemia, hypercarbia,
pulmonary hypertension, polycythemia and finally biventricular failure. These patients are
particularly vulnerable during the post-operative period if opioids or other sedative have
been used. Both obese and patients with Pickwickian syndrome have oxygen demand and
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
171
increased CO2 production due to increased metabolic rate. Expiratory reserve volume,
functional residual capacity and inspiratory reserve volume is greatly decreased in both
conditions. Forced expiratory volume (FEV1) and midexpiratory flow rate (MMEF) are
normal. Preoperatively these patients are increased risk for aspiration. Post-operatively
respiratory failure is the major concern. 1. Morgan GE, Mikhail MS, Murray MJ, (eds.). Clinical Anesthesiology. 3rd edition. Lange Medical Books/McGraw-Hill Publishing Division. NewYork, NY. 2002:748. 145. B Microcytic hypochromic anemia Cyclosporine selectively inhibits helper T-lymphocytes but has no effect on B-lymphocytes.
Cyclosporine is used as an immunosuppressant agent in organ transplant. It is also used in
patients suffering from Crohn’s disease, uveitis, psoriasis, rheumatoid arthritis. The most
common side effect or toxicity of cyclosporine include: nephrotoxicity, hypertension, nerve
paresthesia, headache, seizures, increased liver enzymes, cholestasis, hirsutism, gingival
hyperplasia, and hyperglycemia. Prolonged use can produce myocardial hypertrophy with
ST changes. Cyclosporine promotes tumor growth and can lead to significant increase in
tumor size. Microcytic, hypochromic anemia is due to iron deficiency not cyclosporine. 1. Stoelting RK. Pharmacology and Physiology in Anesthetic Practice. 3rd edition. Lippincott-Raven Publishers. New York, NY. 1999:418. 146. D Resetting discharge from aortic and carotid bodies Propofol, a substituted isoprophylphenol is one of the most common anesthetics inducing
agent used today. It affects cardiovascular system at multiple sites. It produces a decrease
in systematic blood pressure and cardiac output. This decrease is greater than that
produced by thiopental and is due to inhibition of sympathetic vasoconstriction. The cardio-
depressant effect is due to decrease in intracellular Ca ions and is more pronounced in
hypovolumic patients. Propofol produces bradycardia due to vagal stimulation. Rarely
bradycardia may be severe enough to produce asystole. Although propofol may depress
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
172
baroreceptors control of heart rate it does not reset it. Propofol has depressant effects on
ventilation and central nervous system.
1. Stoelting RK. Pharmacology and Physiology in Anesthetic Practice. 3rd edition. Lippincott-Raven Publishers. New York, NY. 1999:143. 147. D Administer thiopental 250 mg intravenously All the choices given can reduce intracranial pressure but D is the most appropriate choice
for an immediate action. Lowering PaCO2 any further than 23 will not decrease the
intracranial pressure. Thiopental is administered to decrease ICP that remains elevated
despite deliberate hyperventilation and drug-induced diuresis. Thiopental decreases
cerebral volume by cerebral vascular vasoconstriction which also increases perfusion
pressure. Lasix decreases intracranial pressure by inducing systematic diuresis, decreasing
cerebrospinal fluid production and resolving cerebral edema by improving cellular water
transport. Mannitol decreases intracranial pressure by increasing plasma osmolarity, which
draws water from the tissues, including brain. Mannitol also decreases the rate of formation
of CSF. It takes 10-15 minutes before mannitol begins to exert its effect which last about 2
hours. An intact blood-brain barrier is necessary otherwise mannitol can enter the brain,
draw fluid with it and can produce rebound hypertension. A combination of Lasix and
mannitol is more effective. However, because of the emergent nature of this case,
administration of thiopental is the best choice.
1. Stoelting RK. Pharmacology and Physiology in Anesthetic Practice. 3rd edition. Lippincott-Raven. New York, NY. 1999:116-118; 438-440.
Anesthesia Practice Questions: Book 1 – 2004
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc.
173
148. C Administer diphenhydramine, cimetidine and fluid This patient has carcinoid tumor which produce carcinoid syndrome, Carcinoid syndrome is
the complex of signs and symptoms caused by secretion of vasoactive substances
(serotonin, kallikrein, histamine) from these tumors. Since most of these tumors are
located in gastrointestinal tract they are destroyed in the liver before they cause systematic
effects. Manual manipulation of the tumor can cause release of vasoactive substances and
multi-system signs and symptoms. These include: cutaneous flushing, changes in blood
pressure, dysrhythmias, bronchospasm, hypo- or hypertension. Of the choices given,
administration of diphenhydramine (histamine antagonist) and cimetidine (H2 receptor
antagonist) with fluids is the most appropriate choice. In general preoperative preparation
of these patients with drugs that block effects of vasoactive substances is indicated. One
such drug is Octreotide. Pretreatment with Octreotide, a synthetic somatostatin analogue
inhibits the release of vasoactive substances.
1. Morgan GE, Mikhail MS, Murray MJ, (eds.). Clinical Anesthesiology. 3rd edition. Lange Medical Books/McGraw-Hill Medical Publishing Division. New York, NY. 2002:749- 750.
K-Type Answers
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
177
149. A (1,2,3) Isoflurane Sevoflurane Desflurane Xenon and nitrous oxide are non-volatile gases with anesthetic properties. Xenon is a noble
gas that has characteristic of an ideal anesthetic. Xenon has a MAC of 71%, making it more
potent than nitrous oxide (MAC 104%). It has a blood:gas partition coefficient of 0.14
which allows for a more rapid emergence. Xenon is nonexplosive, non-pungent, and
odorless. It is unreactive and produces minimal cardiac depression. A key attribute is that
unlike other inhalation anesthetics, including nitrous oxide, it is not harmful to the
environment, especially the ozone. It drawback is the high cost of using xenon. Xenon has
not been shown to be a trigger for malignant hyperthermia in animal studies.
Volatile anesthetics such as isoflurane, sevoflurane and desflurane have all been shown to
be triggers for malignant hyperthermia.
1. Xenon Anaesthesia, Journal of the Royal Society of Medicine, volume 93, Oct 2000:513-517. 150. A (1,2,3) Phenoxybenzamine Phentolamine Prazosin Pheochromocytoma is a catecholamine producing tumor of chromaffin tissue origin. Less
than 0.1% of all cases of hypertension are caused by pheochromocytomas. These tumors
are usually found in the adrenal glands but may found anywhere. These tumors secrete
excessive catecholamines such as norepinephrine and epinephrine.
Symptoms and signs associated with pheochromocytoma include paroxysmal headaches,
excessive sweating, palpitations, hypertension, hyperglycemia, and weight loss.
Catecholamine induced cardiomyopathy may also be present. Laboratory tests for urine
vanillylmandelic acid and catecholamines showed widely varied sensitivity and specificity,
neither of which can diagnose pheochromocytomas 100% of the time. This is due to the
intermittent production and secretion of catecholamines. In fact, presence of the triad of
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
178
symptoms such as paroxysmal headaches, sweating and hypertension, are more specific
and sensitive indicators than any of the above laboratory tests.
Preoperative medical treatment before surgery is generally recommended. The drugs most
commonly used are alpha-adrenergic antagonist such as phenoxybenzamine or prazosin.
Phenoxybenzamine is a non-competitive alpha adrenergic antagonist with mostly alpha-1
(postsynaptic) blocking activity and with some alpha-2 (presynaptic) blocking activity.
Treatment with phenoxybenzamine allows control of hypertension and slow intravascular
volume expansion by reducing alpha mediated vasoconstriction. Because it binds covalently
with alpha receptors, it is relatively long acting (24-48 hours). Prazosin on the other hand is
a shorter acting competitive agent also with mostly alpha-1 (postsynaptic) blocking activity.
Phentolamine is an alpha antagonist administered intravenously. It is an often used
intraoperatively to control hypertension resulting from manipulation of a
pheochromocytoma.
Phenylephrine is a direct alpha agonist and would not be indicated for a patient with a
pheochromocytoma.
1. Barash P, Cullen B, Stoelting R. Clinical Anesthesia, 4th edition, J.B. Lippincott. Philadelphia. 2001:1130-1133. 151. B (1,3) Sensitivity to non-depolarizing muscle relaxants Resistant to depolarizing muscle relaxants Myasthenia gravis is a autoimmune disease involving the neuromuscular junction. The
classic presentation is muscle weakness with exercise of central muscle along with ptosis.
Patients often undergo thymectomy for improvement of this disorder. Treatment also
includes the use of anticholinesterases such as pyridostigmine for improvement of
symptoms.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
179
The untreated myasthenic patient is extremely sensitive to nondepolarizing muscle
relaxants; therefore normal doses should be reduced. On the other hand, these patients
show resistance to depolarizing muscle relaxants such as succinylcholine.
1. Barash P, Cullen B, Stoelting R. Clinical Anesthesia, 4th edition, J.B. Lippincott. Philadelphia. 2001:433. 152. B (1,3) Droperidol Metoclopramide Parkinson’s disease is a degenerative disease of the central nervous system characterized
by destruction of dopamine containing nerve cells in the substantia nigra of the basal
ganglia. The etiology of this destruction is most commonly idiopathic. The most
characteristic clinical features of Parkinson’s disease are resting tremor, cogwheel rigidity of
the extremities, bradykinesia, shuffling gait, stooped posture, and facial immobility. All are
secondary to diminished inhibition of the extrapyramidal motor system.
The vomiting center of the brain is located in the dorsal part of the lateral reticular
formation in the medulla. The vomiting center receives afferents from many different parts
of the body including the chemoreceptor trigger zone (CTZ). The CTZ has receptors for
serotonin, histamine, muscarinic compounds, and dopamine. Treatment for nausea and
vomiting is based on antagonizing the CTZ receptors sites. One of these receptors response
to dopamine and therefore is antagonized with an antidopaminergic medication such as
droperidol and metoclopramide. These drugs also have extrapyramidal side effects due to
this antidopaminergic property and therefore should be avoided in patients with Parkinson’s
disease as they could worsen this condition.
1. Stoelting, RK. Pharmacology and Physiology in Anesthetic Practice. 3rd edition. Lippincott-Raven. Philadelphia.1999:449-450,373-374.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
180
153. A (1,2,3) Propofol Atropine Succinylcholine
Porphyria is inherited disorder involving enzymatic defects in the synthesis of heme. A key
step in heme synthesis is the conversion of succinyl-CoA with glycine to form aminolevulinic
acid (ALA). The enzyme responsible for this reaction is aminolevulinic acid synthetase (ALA
synthetase). The different forms of porphyrias involve enzymatic defects after this step.
Therefore, an excess of ALA in the urine is often helpful in diagnosis of porphyria.
Some drugs can induce ALA synthetase cause an excerebration of symptoms. These drugs
include barbiturates, phenytoin, glutethimide, ethanol, and ergot preparations. Therefore,
barbiturates such as sodium thiopental and methohexital are absolutely contraindicated in
these patients. All the other medications mentioned are safe to administer in patients with
porphyria.
1. Barash P, Cullen B, Stoelting R. Clinical Anesthesia, 4th edition, J.B. Lippincott. Philadelphia. 2001:540-541. 154. A (1,2,3) Hyperventilate Administer glucose plus insulin Administer sodium bicarbonate Hyperkalemia can occur because of increase intake (banked blood transfusion or rapid
infusion of potassium ion), cellular redistribution (acidosis, tissue necrosis, or
succinylcholine use), or decrease renal secretion (acute renal failure). Administering
glucose with insulin and sodium bicarbonate (or hyperventilation) causes the shift of
potassium from the extracellular fluid to the intracellular fluid. Calcium chloride although
used acutely to antagonize the effects of high levels of potassium on the myocardium, it
will not cause the shift of potassium away from the extracellular fluid.
1. Gravenstein N, Kirby RR. Complications in Anesthesiology. 2nd edition. Lippincott. Philadelphia. 1996:473-475.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
181
155. A (1,2,3) Expiratory reserve volume Functional residual capacity Residual volume Pregnancy is associated with many physiologic changes. The most important respiratory
changes is a change in the functional residual capacity (FRC) which can be reduced by 20%
compared to non pregnant patients. This reduction is due to the elevation of the diaphragm
by the enlarging uterus into the abdominal cavity. The volumes that comprise FRC,
expiratory reserve volume and residual volume, are therefore reduced. Vital capacity
however remains unchanged throughout pregnancy.
1. Chestnut DH, Obstetric Anesthesia, Principal and Practice. 2nd edition. Mosby. St. Louis. 1997:18-19. 156. D (4) Osteoporosis in late stages Complex Regional Pain Syndrome Type I (CRPS I) is formally known as reflex sympathetic
dystrophy. CRPS I usually follow a noxious event that does not involve nerve injury or
follow a characteristic peripheral nerve distribution. CRPS II or causalgia has the same
signs and symptoms but occurs after a know nerve injury.
CRPS I presents with a triad of sensory, autonomic and motor signs and symptoms.
Sensory symptoms include pain described as burning and aching. Allodynia and
hyperalgesia is often present. Autonomic signs and symptoms almost always include
edema, skin color changes (erythema or cyanotic), and even changes in skin temperature
(higher or lower) when compared to the other limb. Motor signs and symptoms include
muscle weakness, spasm, and decrease range of motion. Other associated signs can
include trophic changes like increase or decrease nail or hair growth. Osteoporosis is
characteristic of late stages of the disease.
1. Srinivasa RN, et.al., Complex Regional Pain Syndrome I (Reflex Sympathetic Dystrophy), Anesthesiology, 2002:96:1254-1260.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
182
157. B (1,3) Generalized pain in 3 or more sites for 3 months or longer Reproducible tenderness in 11 out of 18 pre specified sites Fibromyalgia is one of the most common causes of musculoskeletal pain. Its etiology is
unknown and it also includes a spectrum of other clinical symptoms such as sleep
disturbances, migraine headaches, irritable bowel syndrome and diffuse pain. Diagnosis is
base on the following criteria:
1. Generalized pain in 3 or more sites for 3 months or longer
2. Exclusion of other conditions that may cause similar symptoms
3. Reproducible tenderness in 11 out of 18 pre specified sites
Fibromyalgia does not have a sympathetic pain component and therefore a stellate
ganglion block or phentolamine infusion would not decrease the pain associated with
fibromyalgia. 1. Warfield, CA, Bajwa, ZH. Principles and Practice of Pain Medicine, 2nd edition, McGraw-Hill. New York NY. 2004:514-515. 158. A (1,2,3) Paroxysm of pain Unilateral facial involvement Trigger zones may be present Trigeminal neuralgia is a severe, usually unilateral facial pain involving the distribution of
cranial nerve V (most often divisions V2 and V3). Trigeminal neuralgia represents the most
frequent neuralgia seen in the elderly. The pain is often describes as sharp or stabbing pain
occurring is paroxysms and separated by pain free intervals. Trigger zones may be present
and light touching of these sites may elicit a paroxysm of pain.
1. Warfield, CA, Bajwa, ZH. Principles and Practice of Pain Medicine, 2nd edition, McGraw-Hill. New York NY. 2004:246-247.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
183
159. A (1, 2, 3) Myosis Ptosis Nasal congestion The sympathetic innervation of the head, neck and arms originate from ganglia formed
from preganglionic nerve fibers emerging from T1and below. The ganglia of the head and
neck consist of three ganglia (the superior, middle and inferior cervical ganglion). All fibers
from to the superior and middle must pass through the inferior cervical ganglion (also
called the stellate ganglion). The stellate ganglion lies along the lateral aspect of the
seventh vertebrae just anterior to its transverse process. This places it behind the carotid
sheath and the vertebral artery, just above the pleura, and in close proximity to the
recurrent laryngeal nerve. Indication for a sympathetic block involving the stellate ganglion
is in sympathetically maintained pain such as complex regional pain syndrome esp. of the
upper extremity.
Signs of successful stellate ganglion block include Horner’s syndrome (ptosis, miosis, and
anhidrosis), injection of the conjunctiva, nasal stuffiness, vasodilation, and increased skin
temperature especially in the upper extremity.
Complications include block of the brachial plexus and recurrent laryngeal nerve or superior
laryngeal nerves, hematoma formation (from the carotid artery), intravascular injection
resulting in convulsions (injecting of even small amounts of local anesthetics via the
vertebral artery), and epidural and subarachnoid injections. Hoarseness would result with
blockade of the recurrent laryngeal nerve.
1. Warfield, CA, Bajwa, ZH. Principles and Practice of Pain Medicine, 2nd edition, McGraw-Hill. New York NY. 2004:696-698.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
184
160. B (1,3) Cricoid cartilage Chassaignac’s tubercle Indication for a sympathetic block involving the stellate ganglion is in sympathetically
maintained pain such as complex regional pain syndrome esp. of the upper extremity. The
stellate ganglion lies along the lateral aspect of the seventh vertebrae just anterior to its
transverse process. This places it behind the carotid sheath and the vertebral artery, just
above the pleura, and in close proximity to the recurrent laryngeal nerve.
The anterior paratracheal approach is performed with the patient in the supine position.
The cricoid cartilage is palpated and then the fingers slide laterally in the groove of the
trachea and sternocleidomastoid muscle. The anterior tubercle of the transverse process of
C-6 (Chassaignac’s tubercle) is then located to perform the block.
The greater cornu of the hyoid bone is the landmark use to perform a superior laryngeal
block while C-3 transverse process is the landmark for a deep cervical plexus block.
1. Warfield, CA, Bajwa, ZH. Principles and Practice of Pain Medicine, 2nd edition, McGraw-Hill. New York NY. 2004:696-698. 161. A (1,2,3) 12th ribs T-12 spinous processes L-1 spinous processes Celiac block is indicated in patients with pain arising from the abdominal viscera, especially
in pancreatic cancer. Relief of pain is almost immediate. Celiac plexus block performed with
a neurolytic agent can provide relief of pain for up to 4 months. The celiac plexus is
generally clustered at the level of the body of L1, posterior to the vena cava on the right,
just lateral to the aorta on the left, and posterior to the pancreas.
The classic approach involves identifying the 12th ribs, and T-12 and L-1 spinous processes.
The sacral hiatus is a landmark for performing the sciatic nerve block.
1. Miller R. Anesthesia. 5th edition. Churchill Livingstone. New York NY. 2000:1545-1546.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
185
162. C (2,4) Intercostobrachial nerve Musculocutaneous nerve The axillary approach to the brachial plexus is the most popular because of ease of block,
reliability of hand and forearm anesthesia, and safety. This block is ideally suited for
outpatients. At the level of the axillary, the musculocutaneous nerve has already left the
brachial plexus and travels within the coracobrachialis muscle. Supplementation of this
nerve is important since it provides sensory to the lateral portion of the forearm. The
intercostobrachial nerve is a branch from T-2 intercostal nerve and provides sensory to the
upper medial arm where if not supplemented will elicit pain when a tourniquet is used.
1. Miller R. Anesthesia. 5th edition. Churchill Livingstone. New York NY. 2000:1524-1527. 163. B (1,3) Spondylolysis Ankylosing spondylitis
Epidural steroid injection appears to be most therapeutic in patients experiencing low back,
neck or extremity pain secondary to nerve root irritation (radicular pain). The mechanism
appears to be from the steroid anti-inflammatory properties. Epidural steroid injection has
been found to be ineffective in spondylolysis and ankylosis spondylitis.
1. Warfield, CA, Bajwa, ZH. Principles and Practice of Pain Medicine, 2nd edition, McGraw-Hill. New York NY. 2004:655-660. 164. E All Clonidine Amitriptyline Gabapentin Morphine Complex Regional Pain Syndrome I (CRPS I) is the new term replacing reflex sympathetic
dystrophy (RSD) while CRPS II replaces the term for the syndrome causalgia. CRPS I
usually follow a noxious event that does not involve nerve injury or follow a characteristic
peripheral nerve distribution. CRPS II has the same clinical signs and symptoms but the
history is significant for a nerve injury.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
186
Pharmacologic management include clonidine (α2 agonist) has been shown to be effective
especially when given by epidural or intrathecal. Amitriptyline (a serotonin and
norepinephrine reuptake blocking agent) is very effective in the treatment of neuropathic
pain such as CRPS. Gabapentin a selective voltage-gated Na2+ channel blocker has shown
efficacy in the treatment of CRPS as well. And finally, opioids such as morphine do have
role in neuropathic pain although they are most effective in nociceptive pain.
1. Warfield, CA, Bajwa, ZH. Principles and Practice of Pain Medicine, 2nd edition, McGraw-Hill. New York NY. 2004:411-412. 165. E All Hypotension Hypothermia Bradycardia Cardiac arrest Hypotension and bradycardia represents the most common serious complications
associated with spinal anesthesia. Blockade of the sympathetic efferents is the mechanism
for these cardiovascular effects. Hypotension is the result vasodilation and redistribution of
central blood volume to the periphery. This results in a drop in venous return and therefore
a decrease in cardiac output. The severity of hypotension is most times (not always)
associated with block height (T5 or greater). Other risk factors include age > 40 years,
starting baseline systolic blood pressure less than 120 mmHg, and spinal puncture above
L3 - L4.
Bradycardia, although less common than hypotension, is also the result of sympathetic
blockade and the risk also associated with block height (T5 or greater). Other risk factors
include a baseline heart rate less than 60 beats/min, ASA classification of I, use of beta
blockers, and pre-existing first degree block.
Hypotension and bradycardia can lead in rare instances to cardiac arrest. Lack of vigilance
and lack of early intervention has often been sighted as reasons contributing to cardiac
arrest.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
187
Both general anesthesia and regional anesthesia result in impairment of thermoregulation.
Hypothermia is the most common thermoregulatory disturbance occurring with spinal
anesthesia. Again the mechanism associated with sympathetic blockade.
1. Spencer SL, et. Al. Current Issues in Spinal Anesthesia, Review Article. Anesthesiology. 2001:94:888-906. 2. Barash P, Cullen B, Stoelting R. Clinical Anesthesia, 4th edition, J.B. Lippincott. Philadelphia. 2001:704-706. 166. D (4) Baricity of local anesthetic It is the cephalad spread of local anesthetic in the cerebrospinal fluid (CSF) that determines
the height of spinal block. Many factors have been suggested to play a role in this spread,
but only baricity and patient position appear to be the most important. Hyperbaric local
anesthetic solutions tend to flow to depended areas, but by changing the position of the
patient, can influence the spread of the solution. Hypobaric solutions on the other hand
tend to spread more readily through the CSF. Increasing the dose and volume of
hyperbaric appears to be unimportant in predicting the spread of either hyperbaric or
isobaric solutions. Patient’s height is a poor predictor of the height of the block.
1. Barash P, Cullen B, Stoelting R. Clinical Anesthesia, 4th edition, J.B. Lippincott. Philadelphia. 2001:697-700. 167. E All Use of adrenergic agonist Type of local anesthetic Drug dose Block height The single most important factor determining the duration of block is the type of local
anesthetic used. Procaine has the shortest duration. Local anesthetics with intermediate
duration include lidocaine and mepivacaine, while those with the longest duration include
bupivacaine and tetracaine. Increasing the dose of local anesthetic also influences the
duration. Interesting the higher the height of the spinal block, the shorter the duration of
the block. The explanation for this is that for a given concentration, the greater the
cephalad spread, the lower the concentration of drug in the CSF and spinal nerve roots.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
188
Finally, the use of adrenergic agonist such as epinephrine and phenylephrine are known to
increase the duration of the spinal block. The mechanism by which adrenergic agonists
prolong spinal block is not clear.
1. Barash P, Cullen B, Stoelting R. Clinical Anesthesia, 4th edition, J.B. Lippincott. Philadelphia. 2001:700-701. 168. A (1,2,3) Sex Age Use of opioids The ability to identify those at risk for postoperative nausea and vomiting narrows the pool
of those needing prophylactic antiemetic therapy. The incidence of PONV in patients with
no risk factors is approximately 10% while those with greater than three risk factors, can
increase the incidence to > 60%.
Patient related risk factors include female gender, history of PONV (or motion sickness) and
nonsmoking status. Anesthetic risk factors include the use of volatile anesthetics, nitrous
oxide and opioids perioperatively. Surgical risk factors are the length of the surgery and in
some cases the type of surgery (i.e., laparoscopy, neurosurgery, ear surgery, etc.).
A smoking history has been shown to be protective against PONV. 1. Gan TT, et. al., Consensus Guideline for Managing Postoperative Nausea and Vomiting. Anesthesia and Analgesia. 2003: 97: 62-71. 169. E All Droperidol Dolasetron Dexamethasone Ondansetron There are several antiemetic medications available for the prophylaxis treatment of PONV.
Among them are the serotonin antagonists such as dolasetron, ondansetron, granisetron
and tropisetron. All are most effective when given at the end of the surgery preferably 30
minutes before the end. Droperidol is also effective and also best given 30 minutes before
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
189
the end of the surgery. Dexamethasone (whose mechanism of action against PONV is
unknown) is also a very effective prophylactic antiemetic and is most effective when
administered at the beginning of the case rather than the end.
1. Gan TT, et. al., Consensus Guideline for Managing Postoperative Nausea and Vomiting. Anesthesia and Analgesia. 2003: 97: 62-71. 170. A (1,2,3) Gradual metabolism Redistribution Administration of cholinesterase inhibitors
With the exception of mivacurium (which is metabolized significantly by
pseudocholinesterase), reversal of blockade by nondepolarizing agents depends on
redistribution, gradual metabolism and excretion by the body, or administration of
cholinesterase inhibitors.
Duration of action of nondepolarizing drugs is determined by the time required for plasma
concentration to decrease below a critical level. As is the case for other drugs used in
anesthesia, the elimination half-life of neuromuscular blocking agents does not always
correlate with duration of action because termination of action sometimes depend on
redistribution instead of elimination.
The pharmacokinetic variables of vecuronium are similar to those of pancuronium. The
reason for vecuronium’s intermediate-duration of action is that the plasma concentration
decreases through the effective range far more rapidly so that duration and recovery
depend more on distribution than on elimination. However after prolonged infusion of
vecuronium (in excess of 6 h), the peripheral storage sites have become saturated and a
decrease in plasma concentration is then dependent upon metabolism and excretion not
upon redistribution.
Recovery after reversal is dependent on the rate of spontaneous recovery as well as the
acceleration induced by the reversal agent. 1. Neuromuscular blocking agents. In Morgan, Jr. GE, Mikhail MS, Murray MJ, Larson, Jr. CP (eds.). Clinical Anesthesiology. 3rd edition McGraw-Hill, 2002:182. 2. Bevan DR, Donati F. Muscle relaxants. In Barash PG, Cullen BF, Stoelting RK (eds.). Clinical Anesthesia. 4th edition Lippincott Williams & Wilkins, Philadelphia, PA. 2001:431,440.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
190
171. A (1,2,3) The combination of Rocuronium and Cis-atracurium are synergistic Pre curarizing dose of D-Tubocurarine will shorten the duration of action of succinylcholine The potency of Rocuronium is enhanced when administered after succinylcholine
The duration of suxamethonium neuromuscular blockade following pancuronium
pretreatment has shown to be significantly prolonged (not shorter) due to the
cholinesterase inhibition caused by pancuronium.
Combinations of similar drugs - pancuronium/vecuronium (amino steroids),
atracurium/mivacurium (benzyl isoquinoline) - have additive effects. Other combinations
tend to show potentiation. Combinations of rocuronium (aminosteroid) and cisatracurium
(benzyl isoquinolinium) are synergistic.
In general, the depolarizing and non-depolarizing relaxants are mutually antagonistic and it
has been suggested that the dose of suxamethonium should be increased after
precurarization.
The duration of suxamethonium neuromuscular blockade following pancuronium
pretreatment has shown to be significantly prolonged due to the cholinesterase inhibition
caused by pancuronium. This effect is more marked with the smaller than the larger doses
of pancuronium, because at larger doses antagonistic action predominates.
Conversely, the potency of nondepolarizing drugs is enhanced when they are administered
after succinylcholine. The reason for this potentiation is not clear.
The response to a small dose of succinylcholine at the end of an anesthetic in which a
nondepolarizing agent has been used is difficult to predict. It may either antagonize or
potentiate the blockade, depending on the degree of nondepolarizing block. 1. Bevan DR, Donati F. Muscle relaxants. In Barash PG, Cullen BF, Stoelting RK (eds.). Clinical Anesthesia, 4th edition Lippincott Williams & Wilkins, Philadelphia, PA. 2001:432 2. Freund FG, Rubin AP. The need for additional succinylcholine after d-tubocurarine. Anesthesiology 1972;36:185-7 3. Stovner J, Oftedal N, Holmboe J. The inhibition of cholinesterases by pancuronium. Br. j. Anaesth. 1975;47:949-54 4. Krieg N, Hendrickx HHL, Crul JF: Influence of suxamethonium on the potency of ORG NC 45 in anesthetized patients. Br J Anaesth 1981;53:259
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
191
172. A (1,2,3) The response of the orbicularis oculi over the eyelid is similar to that of the adductor pollicis The response of the eyebrow (corrugator supercilii) is similar to that of the laryngeal adductors The onset of neuromuscular blockade occurs earlier at the diaphragm The dose response curve for the diaphragm is shifted to the right.
Muscles around the eye vary in their response to rocuronium. The response of the
superciliary arch (corrugator supercilii) reflects blockade of laryngeal adductor muscles.
However, the eyelid (orbicularis oculi) and thumb (adductor pollicis) have similar
sensitivities.
The dose required for 90% blockade has been reported to be 40-100% greater for the
diaphragm than for the adductor pollicis. The decreased sensitivity probably explains the
earlier recovery of the diaphragm. However, onset of neuromuscular blockade occurs
earlier at the diaphragm. This is believed to be due to the greater muscle blood flow
allowing earlier distribution and higher peak concentration of muscle relaxants at the
neuromuscular junction of the diaphragm as compared to the adductor pollicis.
1. Plaud B, Debaene B, Donati F. The corrugator supercilii,not the orbicularis oculi, reflects rocuronium neuromuscular blockade at the laryngeal muscles. Anesthesiology. 2001;95(1);96-101 2. Bevan DR, Donati F. Muscle relaxants. In Barash PG, Cullen BF, Stoelting RK (eds.). Clinical Anesthesia 4th edition Lippincott Williams & Wilkins, Philadelphia, PA. 2001:436 3. Lebreault C, Chauvin M, Guirimand F, Duvaldestin P: Relative potency of vecuronium on the diaphragm and the adductor pollicis. Br J Anaesth 1989; 63:389-392 173. E All Protection of the airway against regurgitation can be impaired Most patients complain of visual symptoms In the majority of patients, sustained bite is not present Grip strength can be decreased At TOF ratio of 0.7 most patients have signs and symptoms of significant paralysis.
In one study involving volunteers, at a TOF ratio of 0.70 (at the adductor pollicis) none of
the subjects found airway maintenance a problem, but all agreed that they were not “street
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
192
ready”. Although symptoms varied from subject to subject, TOFs in the range of 0.70-0.75
were associated with all of the following symptoms:
1. Diplopia and various visual disturbances (Most patients complain of visual
symptoms until TOF ratio was greater than 0.9)
2. Decreased grip strength
3. Inability to maintain incisor teeth apposition (In the majority of patients,
sustained bite does not return until the TOF ratio exceeds 0.85)
4. Inability to sit up without assistance
5. Severe facial weakness including an inability to make an airtight seal around a
drinking straw with the lips, speaking describes as a major effort
6. Overall weakness and tiredness
The results of these investigations indicate that normal respiratory and upper airway
function does not return to normal unless the TOF ratio at the adductor pollicis is 0.9 or
more.
1. Donati F, Meistelman C, Plaud B. Relationship of the TOF fade ratio to clinical signs and symptoms of residual paralysis in awake volunteers. Anesthesiology 1997;86:765-71 2. Bevan DR, Donati F. Muscle relaxants. In Barash PG, Cullen BF, Stoelting RK (eds.). Clinical Anesthesia. 4th edition Lippincott Williams & Wilkins, Philadelphia, PA. 2001:437 174. C (2,4) The post tetanic twitch count should not be repeated more often than every 5 minutes The most sensitive test for detecting residual paralysis is the ability to maintain sustained contractions to 100Hz of tetanus for 5 seconds TOF stimulation can be repeated after a pause of 10 seconds, not every 5 sec. The
presence of small number of impulses eliminates the problem of post-tetanic facilitation
and stimulation can be repeated after a pause of 10 seconds.
When assessing tactile/visual muscular activity in response to nerve stimulation, TOF and
double-burst stimulation can reliably detect fade when the TOF is <0.4 and 0.6,
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
193
respectively. On the other hand, studies have shown that at a TOF ratio of 0.7, most
subjects had significant signs and symptoms of residual paralysis.
It has been shown that 100Hz, 5–s tetanic nerve stimulation is a very good reference test
for detecting clinical fading at the adductor pollicis (AP), because a high level TOF ratio can
be detected. The absence of visual fading at the AP, elicited in anesthetized patents by
100-Hz, 5-s tetanus, is compatible with a TOF ratio > 0.85.
1. Bevan DR, Donati F. Muscle relaxants. In Barash PG, Cullen BF, Stoelting RK (eds.) Clinical Anesthesia. 4th edition Lippincott Williams & Wilkins, Philadelphia, PA. 2001:434 2. Viby-Mogensen J, Jensen NH, Engbaek J, et al. Tactile and visual evaluation of the response to train-of-four nerve stimulation. Anesthesiology 1985;63:440-3 3. Drenck NE, Ueda N, Olsen NV, et al. Manual evaluation of residual curarization using double-burst stimulation: a comparison with train-of-four. Anesthesiology1989;70:578-81 4. Kopman AF, Yee PS, Neuman GG. Relationship of the train-of-four fade ratio to clinical signs and symptoms of residual paralysis in awake volunteers. Anesthesiology 1997;86:765-71. 5. Baurain MJ, Hennart DA, Godschalx A, et al. Visual evaluation of residual curarization in anesthetized patients using one hundred-Hertz, five-second tetanic stimulation at the adductor pollicis muscle. Anesth analg 1998;87:185-9 175. B (1,3) May develop cardiac arrest following the administration of a depolarizing muscle relaxant Has a less intense block on the affected limb Monitoring of the affected side (not the unaffected) shows that the block is less intense and
recovery is more rapid than the unaffected side.
The patients with hemiplegia or quadriplegia as a result of central nervous system lesion
show an abnormal response to muscle relaxants. Hyperkalemia and cardiac arrest have
been described after succinylcholine, and probably related to potassium loss via a
proliferation of extra junctional receptors.
The hemiplegic patients are resistant to nondepolarizing muscle relaxants. Monitoring of
the affected side shows that the block is less intense and recovery is more rapid than the
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
194
unaffected side. Therefore, monitoring of the involved limb tends to underestimate the
block and the noninvolved limb should be used.
1. Bevan DR, Donati F. Muscle relaxants. In Barash PG, Cullen BF, Stoelting RK (eds): Clinical Anesthesia. 4th edition. Lippincott Williams & Wilkins, Philadelphia, PA. 2001:433, 437 176. B (1,3) Is functionally similar to Mapleson E and F systems Requires high fresh gas flows to prevent rebreathing of carbon dioxide Mapleson has a T-piece near the patient end, and is more efficient during controlled
ventilation. Mapleson A is the most efficient system during spontaneous ventilation.
The Mapleson D, E and F have a T piece near the patient end and they function similarly.
Mapleson D is the most efficient Mapleson system during controlled ventilation. To prevent
rebreathing CO2, the DEF systems require a fresh gas inflow rate of 2.5 times the minute
ventilation.
Dorsch JA, Dorsch SE. Understanding anesthesia equipment. 4th edition Williams & Wilkins, Baltimore, MD. 1999:211 177. B (1,3) Is located downstream from the nitrous oxide supply source Is located upstream of the flow control valves The fail-safe valve shuts interrupts the supply of nitrous oxide if the oxygen supply
pressure (not the oxygen flow) decreases. This device does not offer total protection
against a hypoxic mixture being delivered.
Fail-safe device is located downstream from the nitrous oxide supply and upstream of the
flow control valves. This valve shuts off or proportionately decreases and ultimately shuts
off nitrous oxide and other gases if the oxygen supply pressure (not the oxygen flow)
decreases. This device does not offer total protection against a hypoxic mixture being
delivered. The device aid in preventing hypoxia caused by some problems occurring
upstream of flow control valves only. These include disconnected oxygen hose and
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
195
depletion of oxygen cylinders. They do not guard against accidental crossovers in the
pipeline system. Use of an oxygen analyzer near the patient end is essential.
1. Andrews JJ, Brockwell RC. Delivery systems for inhaled anesthetics. In Barash PG, Cullen BF, Stoelting RK (eds.). Clinical Anesthesia. 4th edition. Lippincott Williams & Wilkins, Philadelphia, PA. 2001:567 2. Dorsch JA, Dorsch SE. Understanding anesthesia equipment. 4th edition. Williams & Wilkins. Baltimore, MD. 1999:95,96 178. E All Allergic reactions to local anesthetics remain uncommon despite their frequent use Muscle relaxants are the most frequently involved drugs Anaphylactoid reactions are considered to activate only basophils Increased concentration of tryptase (greater than 25 µg/L) suggest an anaphylactic reaction Among the drugs and other agents involved in anaphylaxis, muscle relaxants are still most
frequently involved. Rocuronium seems to be the most frequently involved agent (43.1%),
whereas the number of cases involving succinylcholine remains relatively stable (22.6%).
Anaphylaxis involves the activation of basophils and mast cell, whereas non-immune
mediated anaphylactoid reactions are considered to activate only basophils. Mast cells
activated during an IgE-mediated hypersensitivity reaction release proteases such as
tryptase, pre-stored histamine, and newly generated vasoactive mediators. Therefore,
increased concentration of tryptase greater than 25 µg/L is considered as a highly sensitive
indicator of anaphylactic reaction during anesthesia, although elevated tryptase can be
observed in other situation.
1. Laxenaire M, Mertes PM. Anaphylaxis during anesthesia: Results of a 2 year survey in France. Br J Anaesth 2001;21:549-58 2. Mertes PM, Laxenaire M, Alla F. Anaphylactic and anaphylactoid reactions occurring during anesthesia in France in 1999-2000. Anesthesiology 2003;99:536-45
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
196
179. B (1,3) Unidirectional valves should be close to the patient The pressure relief valve should be placed immediately before the absorber Unidirectional valves should be close to the patient to prevent back flow into the inspiratory
limb if a circuit leak develops.
The fresh gas inlet should be placed between the absorber and the inspiratory valve.
Positioning it downstream from the inspiratory valve would allow fresh gas to bypass the
patient during exhalation and be wasted. Fresh gas introduced between the expiration
valve and the absorber would be diluted by recirculating gas and also may be absorbed by
soda lime, thus slowing induction and emergence.
The pressure-relief valve should be placed immediately before the absorber to conserve
absorption capacity. The resistance to exhalation is decreased by locating the breathing
bag in the expiratory limb.
1. Breathing systems. In Morgan, Jr. GE, Mikhail MS, Murray MJ, Larson, Jr. CP (eds): Clinical Anesthesiology.3rd edition McGraw-Hill, 2002 ;35 180. B (1,3) Bronchospasm Increased inspiratory gas flow rate Peak inspiratory pressure (PIP) is the highest circuit pressure generated during an
inspiratory cycle, and provides an indication of dynamic compliance. Plateau pressure
(PP) is the pressure measured during an inspiratory pause (a time of no gas flow), and
mirrors static compliance. An increase in both PIP and PP implies an increase in tidal
volume or decrease in pulmonary compliance (i.e. pulmonary edema, pleural effusion,
tension pneumothorax, ascites)
An increase in PIP without any change in PP signals an increase in airway resistance
(bronchospasm, secretions) or inspiratory gas flow rate.
1. The anesthesia machine. In Morgan, Jr. GE, Mikhail MS, Murray MJ, Larson, Jr. CP (eds): Clinical Anesthesiology.3rd edition McGraw-Hill, 2002 ;47
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
197
181. A (1,2,3) Laryngospasm Laryngeal edema Foreign body aspiration The differential diagnosis of acute onset, post-operative inspiratory stridor includes:
1. Laryngospasm - involuntary spasm of the laryngeal musculature triggered by
blood or secretions stimulating the superior laryngeal nerve.
2. Laryngeal edema caused by an allergic reaction to drugs or traumatic intubation
3. Vocal cord dysfunction due to residual muscle relaxant effect
4. Hypocalcemic tetany
5. Vocal cord dysfunction due to bilateral recurrent laryngeal nerve palsy
Superior laryngeal nerve provides motor innervation to cricothyroid muscle (adductors of
the vocal cords) only and bilateral palsy results in hoarseness or easy tiring of the voice,
but airway control is not jeopardized.
Assuming an intact superior laryngeal nerve, acute bilateral recurrent laryngeal nerve palsy
can result in stridor and respiratory distress. This is due to the unopposed tension of the
cricothyroid muscle.
1. Anesthesia for otorhinolaryngologic surgery. In Morgan, Jr. GE, Mikhail MS, Murray MJ, Larson, Jr. CP (eds): Clinical Anesthesiology.3rd edition McGraw-Hill, 2002:780. 182. E All Incidence of radial artery thrombosis can be minimized by avoiding tapered catheters Arterial sampling is an important source of bacterial contamination of transducer systems Cerebral air embolism is a possible complication Systolic pressure reading at the radial artery exceeds that of the aortic root Arterial cannulation is regarded as an invasive procedure with a documented morbidity.
Ischemia, hemorrhage, thrombosis, embolism, cerebral embolism (retrograde flow
associated with flushing) aneurysm formation, arteriovenous fistula formation, skin
necrosis, and infection have occurred as a direct result of arterial cannulation, arterial blood
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
198
sampling, or high pressure flushing. Incidence of radial artery thrombosis can be minimized
by avoiding tapered catheters.
Because retrograde arterial embolism is possible whenever forceful flushing of a peripheral
arterial catheter is performed, special care should be exercised whenever more centrally
located arterial catheters are used.
Arterial sampling was found to be an important source of bacterial contamination.
Compared with central aortic pressure, peripheral waveform have higher systolic, lower
diastolic and wide pulse pressure. Despite this the MAP in the aorta is only slightly greater
than that in the radial artery. 1. Murphy GS, Vender JS Monitoring of the anesthetized patient. In Barash PG, Cullen BF, Stoelting RK (eds): Clinical Anesthesia. 4th edition. Lippincott Williams & Wilkins, Philadelphia, PA. 2001:674 2. Mark JB, Slaughter TF, Reves JG Cardiovascular Monitoring. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:1131 3. Shinozaki T, Dean RS, Mazuzan JE et al: Bacterial contamination of arterial lines: A prospective study. JAMA 1983;249:233 183. E All Are used intraoperatively to evaluate the functional integrity of sensory and motor pathways. Of brain stem origin (BAEP) are less vulnerable to anesthetic agents than the evoked potentials of cortical origin (cortical component of SSEP or VEP). Are minimally affected by opioids. Are minimally affected by N2O at concentrations of less than 50%. The sensitivity of evoked potentials to drug effects varies with the sensory modality being
monitored. Evoked potentials of cortical origin (i.e., the cortical component of the
somatosensory evoked potentials-SSEP and visual evoked potentials –VEP) are more
vulnerable to anesthetic influences than brain stem potentials (e.g., brain stem auditory
evoked potentials – BAEP and the subcortical components of the SSEP).
Because opioids preserve SEP recordings even in relatively high doses, they are
recommended for use as infusions during intraoperative monitoring.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
199
Motor evoked potentials (MEPs) are extremely sensitive to depression by anesthetics.
However, N2O concentration of 50% is reported to cause minimal response alteration and
appears to be compatible with monitoring.
1. Bendo AA, Kass IS, Hartung J, Cottrell JE. Anesthesia for Neurosurgery. In Barash PG, Cullen BF, Stoelting RK (eds): Clinical Anesthesia. 4th edition. Lippincott Williams & Wilkins, Philadelphia, PA. 2001:754,757. 184. A (1,2,3) Is a synthetic opioid Is a selective µ-opioid receptor agonist Has an elimination half-life of about 9 minutes Remifentanil is a selective mu opioid agonist with an analgesic potency similar to that of
fentanyl. Although chemically related to the fentanyl family of short acting phenylpiperidine
derivatives, remifentanil is structurally unique because of its ester linkage. This ester
structure of remifentanil renders it susceptible to hydrolysis by nonspecific plasma and
tissue esterases to inactive metabolites. Because pseudocholinesterase does not appear to
metabolize remifentanil, plasma cholinesterase deficiency and anticholinergic administration
are not expected to affect remifentanil clearance.
1. Coda BA. Opioids. In Barash PG, Cullen BF, Stoelting RK (eds): Clinical Anesthesia. 4th edition. Lippincott Williams & Wilkins, Philadelphia, PA. 2001:366 2. Manullang J, Egan TD: Remifentanil’s effect is not prolonged in a patient with pseudocholinesterase deficiency. Anesth Analg 1999;89:529-530 3. Opioid Agonists and Antagonists. In Stoelting RK (ed) Pharmacology and Physiology in Anesthetic Practice. 3rd edition. Lippincott Williams & Wilkins, Philadelphia, PA. 1999;100. 185. A (1,2,3) Does not suppress myocardial contractility at clinical doses
When administered orally, morphine-6-glucuronide (M6G) is the primary active compound
Has a bioavailability of <30% when administered orally At clinically relevant doses, morphine does not suppress myocardial contractility.
Morphine induced histamine release is not prevented by pretreatment with naloxone,
suggesting that histamine release is not mediated by opioid receptors.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
200
Morphine-3-glucuronide (M3G) is the major metabolite of morphine, but it does not bind to
opioid receptors and has little or no analgesic activity. Morphine-6-glucuronide (M6G),
which accounts for nearly 10% of the morphine’s metabolism, is a more potent mu
receptor agonist than morphine with a similar duration of action. M6G contributes
substantially to the analgesic effects of morphine even in patients with normal renal
function and appears to have a more favorable side effect profile than morphine.
The bioavailability of orally administered morphine is significantly lower (20-30%) than
after IM or subcutaneous injection, because of its high hepatic extraction ratio. The high
hepatic first pass effect also result in substantial level of M6G when morphine is
administered orally. It appears that M6G is in fact the primary active compound when
morphine is administered orally.
1. Coda BA. Opioids. In Barash PG, Cullen BF, Stoelting RK (eds): Clinical Anesthesia. 4th edition. Lippincott Williams & Wilkins, Philadelphia, PA. 2001:351. 2. Bailey PL, Egan TD, Stanley TH. Intravenous Opioid Anesthesia. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:313. 3. Hanna MH, Peat SJ, Knibb AA et al: Disposition of morphine-6-glucuronide and morphine in healthy volunteers. Br J Anaesth. 1991;66:103-7. 186. C (2,4) Can be decreased or prevented by pretreatment with muscle relaxants Is mu receptor mediated Although the precise mechanism of opioid induced muscle rigidity is not clearly understood,
it is not due to a direct action on muscle fibers. It can be decreased or prevented by
pretreatment with muscle relaxants and is not associated with increase in creatinine kinase.
This suggests that there is little or no muscle damage. Mu receptor agonists induced
rigidity in the rat, whereas delta and kappa agonists did not.
1. Bailey PL, Egan TD, Stanley TH. Intravenous Opioid Anesthesia. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
201
187. B (1,3) Is a more potent mu receptor agonist than morphine Has duration of action similar to that of morphine Morphine-3-glucuronide (M3G) is the major metabolite of morphine, but it does not bind to
opioid receptors and has little or no analgesic activity. Morphine-6-glucuronide (M6G),
which accounts for nearly 10% of the morphine’s metabolism, is a more potent mu
receptor agonist than morphine with a similar duration of action.
M6G contributes substantially to the analgesic effects of morphine even in patients with
normal renal function and appears to have a more favorable side effect profile than
morphine. It appears that M6G is in fact the primary active compound when morphine is
administered orally.
1. Bailey PL, Egan TD, Stanley TH. Intravenous Opioid Anesthesia. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:313 2. Hanna MH, Peat SJ, Knibb AA et al: Disposition of morphine-6-glucuronide and morphine in healthy volunteers. Br J Anaesth. 1991;66:103-7 188. A (1,2,3) Is a selective antagonist at 5-HT3 receptors May cause prolongation of the QT interval Is effective in the treatment of perioperative nausea and vomiting Ondansetron is structurally related to serotonin and posses specific serotonin (5-HT3)
subtype receptor antagonist properties, without altering dopamine, histamine, adrenergic,
or cholinergic receptor activity. Ondansetron, 4 to 8 mg IV (administered over 2 to 5
minutes immediately before induction of anesthesia), is highly effective in decreasing the
incidence of postoperative nausea and vomiting in a susceptible patient population
(ambulatory gynecologic surgery, middle ear surgery). In addition to prophylaxis,
ondansetron, 1 to 8 mg IV is highly effective in the treatment of postoperative nausea and
vomiting.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
202
All the 5 HT3 receptor antagonists can prolong the QT interval and can produce
arrhythmias. Unlike metoclopramide, these agents do not affect GI motility or lower
esophageal sphincter tone.
1. White PF, Droperidol: a cost-effective antiemetic for over thirty years. Anesth Analg 2002;95:789-90 2. Adjuncts to anesthesia. In Morgan, Jr. GE, Mikhail MS, Murray MJ, Larson, Jr. CP (eds): Clinical Anesthesiology.3rd edition McGraw-Hill, 2002 ;247 3. Non barbiturate induction drugs. In Stoelting RK (ed) Pharmacology and Physiology in Anesthetic Practice. 3rd edition. Lippincott Williams & Wilkins, Philadelphia, PA. 1999;406. 189. A (1,2,3) Is a highly selective alpha-2 –adrenergic agonist Frequently causes dry mouth Causes bradycardia Medetomidine is a highly selective alpha-2 – adrenergic agonist and dexmedetomidine is its
specific stereoisomer.
A frequently reported side effect of dexmedetomidine has been a dry mouth, which is due
a decrease in saliva production.
The basic side effects of alpha-2 – adrenergic agonists on the cardiovascular system are
decreased heart rate, decreased systemic vascular resistance and indirectly decreased
myocardial contractility, cardiac output, and systemic blood pressure. Intravenous
dexmedetomidine has a biphasic effect on blood pressure. There is an initial increase in
blood pressure due to its effect on peripheral alpha-2 receptors.
Dexmedetomidine reduces the MAC of the potent volatile anesthetics by 30-50%.
1. Reves JG, Glass PSA, Lubarsky DA. Nonbarbiturate Intravenous Anesthetics. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:259-261.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
203
190. A (1,2,3) Has minimal intrinsic activity When used to reverse Diazepam, the potential for re-sedation exists Can precipitate withdrawal symptoms in patients physically dependent on benzodiazepines According to the pharmacological studies, flumazenil is a benzodiazepine receptor ligand
with high affinity, great specificity, by definition minimal intrinsic activity.
Flumazenil, because of its high-affinity to benzodiazepine receptor, will replace relatively
weak agonists such as diazepam as long as it is given in sufficient dose. Since flumazenil is
cleared relatively rapidly, (plasma half life one hour) the receptors occupied by agonist will
increase overtime, and thus potential for resedation exist. This is less likely with
midazolam, since it has a rapid clearance also.
Flumazenil can precipitate withdrawal symptoms in humans physically dependent on a
benzodiazepine receptor agonist.
1. Reves JG, Glass PSA, Lubarsky DA Nonbarbiturate Intravenous Anesthetics. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:237-239 191. B (1,3) Is a synthetic colloid solution Is degraded by amylase Hydroxyethyl starch (HES) compounds are a group of polydispersed synthetic colloids that
resemble glycogen structurally. HESs are synthesized from amylopectin, a waxy starch
derived from maize or sorghum. Amylopectin is a D-glucose polymer with a branching
structure. Reaction with ethylene oxide in the presence of an alkaline catalyst results in
hydroxyethyl substitution. The unsubstituted starch is rapidly hydrolyzed by nonspecific
alpha-amylase in the plasma, and substitution with hydroxyethyl groups substantially slows
this process.
Dextran, (not Hydroxyethyl starch) interferes with the cross matching due to rouleaux
formation.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
204
There is minimal interference with subsequent cross matching with hydroxyethyl and
allergic reactions are very rare.
1. McKinlay S, Gan TJ. Intraoperative Fluid Management and Choice of Fluids. ASA Refresher Course. Lippincott Williams & Wilkins, Philadelphia, PA. 2003:130-131. 2. Kaye AD, Grogono AW. Fluid and Electrolyte Physiology. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:1604 192. A (1,2,3) High concentration of volatile anesthetics may virtually obliterate the hypercarbia-induced increase in ventilatory drive. All volatile anesthetics decrease tidal volume. Most volatile agents depress the ventilatory response to hypoxia at subanesthetic concentrations. All inhaled anesthetics dose dependently depress the ventilatory response to hypercarbia
and high concentrations may virtually obliterate the response.
In general, all volatile agents decrease tidal volume. However, the resultant depression of
minute ventilation may be partially offset by a concomitant increase in respiratory rate.
Subanesthetic concentrations of most volatile anesthetics depress the ventilatory response
to hypoxia in normocapnic, quiet resting subjects, but desflurane does appear to be an
exception. However, it has been shown that subanesthetic concentrations of desflurane do
decrease hypoxic sensitivity during concomitant hypercapnia, suggesting an effect at the
peripheral chemoreceptors.
All volatile anesthetics significantly reduces respiratory system resistance, equi-MAC
sevoflurane decreased resistance as much as halothane and more so than isoflurane.
1. Farber NE, Pagel PS, Warltier DC.. Pulmonary Pharmacology. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:128-142 2. Dahan A, Sarton E et al: Ventilatory response to hypoxia in humans: influences of subanesthetic desflurane. Anesthesiology 1996;85:60-68
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
205
193. C (2,4) Causes subacute combined degeneration of the spinal cord only after several months of daily exposure. Causes very low methionine synthetase activity after a few hours of anesthesia. Nitrous oxide (N2O) is the only anesthetic reported to produce hematological and
neurological toxicity with long-term administration. Both effects are due to interaction of
N2O with vitamin B12 and irreversible oxidation of the cobalt in vitamin B12 by a
physicochemical reaction. Methionine synthetase and thymidylate synthetase are vitamin
B12 dependent enzymes and require vitamin B12 in the completely reduced form to act as
its coenzyme.
These two enzymes are involved in the formation of myelin and the formation of DNA and
therefore, inhibition of these manifests as neurologic disturbances and depression of bone
marrow function.
The half time for (irreversible) inactivation of methionine synthetase is shown to be 46 min
when 70% N2O is administered to patients.
In healthy patients megaloblastic changes are seen after about 12 hour exposure to 50%
N2O. The neurological disease (subacute combined degeneration of the spinal cord)
develops only after several months of daily exposure to N2O.
Experimental data suggest that there is a threshold concentration of about 1,000 ppm
(0.1%) below which N2O has no biochemical effect.
1. Baden JM, Rice SA Metabolism and toxicity of inhaled Anesthetics. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:162-163 2. Ebert TJ, Schmid PG in Inhalation Anesthesia. In Barash PG, Cullen BF, Stoelting RK (eds): Clinical Anesthesia. 4th edition. Lippincott Williams & Wilkins, Philadelphia, PA. 2001:402-403 3. Royston BD, Nunn JF, Weinbren HK et al: Rate of inactivation of human and rodent hepatic methionine synthase by nitrous oxide. Anesthesiology1988;68:213-216 4. Sharer NM, Nunn JF, Royston JP et al: Effects of chronic exposure to nitrous oxide on methionine synthetase activity. Br j Anaesth 1983;5:693-701
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
206
194. D (4) Expansion of air filled spaces Volatile anesthetics produce a dose-dependent decrease in uterine smooth muscle
contractility, but nitrous oxide has no such effect.
There is a small increase in pulmonary vascular resistance with nitrous oxide, which is more
pronounced in patients with pulmonary hypertension.
There is increase in sympathetic nervous system activity with nitrous oxide, which offset
the direct negative inotropic action on the heart.
Nitrous oxide expands air filled spaces because of its greater solubility in blood compared
to nitrogen (i.e., 34 times more soluble in blood than nitrogen). Therefore, nitrous oxide
tends to diffuse into air-containing cavities more rapidly than nitrogen is absorbed by the
blood stream.
1. Pagel PS, Farber NE, Warltier DC. Cardiovascular Pharmacology. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:96-116 2. Ebert TJ, Schmid PG in Inhalation Anesthesia. In Barash PG, Cullen BF, Stoelting RK (eds): Clinical Anesthesia. 4th edition. Lippincott Williams & Wilkins, Philadelphia, PA. 2001:402-403 195. A (1,2,3) Dryness of the carbon dioxide absorbant High temperature of the carbon dioxide absorbant Prolonged high fresh gas flows Carbon monoxide formation occurs with degradation of volatile agents containing a CHF2
moiety by the strong bases in carbon dioxide absorbants. Carbon monoxide production is
influenced by:
a) Dryness of the absorbent with hydration preventing formation
b) High temperature of the absorbant such as during low fresh gas flow and
increased metabolic production of carbon dioxide
c) Prolonged high fresh gas flow causing dryness of the absorbant
d) Type of absorbent (Baralyme>soda lime)
1. Inhaled Anesthetics in Stoelting RK (editor) Physiology & Pharmacology in Anesthetic Practice. Third edition. Lippincott Williams & Wilkins, Philadelphia, PA. 1999:71
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
207
196. B (1,3) Causes formation of organic and inorganic fluoride metabolites. Produces peak plasma fluoride concentrations that are higher than after comparable doses of enflurane. 5% of absorbed sevoflurane undergoes oxidative metabolism to form organic and inorganic
fluoride metabolites.
Sevoflurane does not undergo metabolism to acetyl halide that could result in formation of
trifluoroacetylated liver proteins. Therefore, sevoflurane cannot stimulate the formation of
antitrifluoroacetylated protein antibodies leading to hepatotoxicity by this mechanism.
Peak plasma concentrations are higher than after comparable dose of enflurane. Because
of the limited exposure of renal tubules to fluoride due to rapid elimination of sevoflurane,
there is a less of a nephrotoxic risk. Furthermore hepatic production of fluoride from
sevoflurane may be less of a nephrotoxic risk than is intrarenal production of fluoride from
enflurane.
Carbon monoxide formation reflects the degradation of volatile agents containing a CHF2-
moiety- namely desflurane, enflurane and isoflurane, (not sevoflurane) by strong bases
present in carbon dioxide absorbents.
1. Inhaled Anesthetics in Stoelting RK (editor) Physiology & Pharmacology in Anesthetic Practice. Third edition. Lippincott Williams & Wilkins, Philadelphia, PA. 1999:71 197. A (1,2,3) Is primarily a result of inferior vena caval occlusion May reduce the blood flow to the uterus by as much as 45% Causes approximately 1 in 10 pregnant women to become symptomatic Supine hypotension syndrome is primarily a result of inferior vena caval occlusion, but
aortic compression also contributes to it in some. Flow to the uterus (and lower limbs) may
be reduced by as much as 45% without systemic signs or evidence of aortic compression.
The effect on the venous return depends on the efficiency of the collateral azygous and
intervertebral venous plexuses. Approximately 1 in 10 pregnant women become
symptomatic, with pallor, sweating, nausea and hypotension, accompanied by bradycardia
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
208
and fall in cerebral blood flow and unconsciousness. The Trendelenburg position may
actually worsen aortocaval compression.
1. Kerr MG, Scott DB, Samuel E. Studies of the inferior vena cava in late pregnancy: BMJ 1964;1:532-3 2. Kinsella SM, Lee A, Spencer JA: Maternal and fetal effects of the supine and pelvic tit positions in late pregnancy. Eur J Obstet Gynecol Reprod Biol 1990;36:11 3. Ross A. Physiological changes of pregnancy. In Birnbach DJ, Gatt SP, Datta S (eds): Textbook of Obstetric Anesthesia .Churchill Livingstone Philadelphia, PA. 2000:35 198. C (2,4) Decrease in the colloid oncotic pressure Threefold elevation of alkaline phosphatase Physiological changes of pregnancy do not cause changes in the central venous pressure.
Hemoglobin increases at a slower rate than plasma volume and accounts for the relative
anemia of pregnancy.
There is three-fold elevation of alkaline phosphatase (mainly placental origin).
Colloid osmotic pressure decreases in pregnancy, chiefly following a decrease in albumin
level. The precise etiology remains obscure Albumin level falls to a minimum immediately
after delivery. Although the incidence of pulmonary edema remains low after both cesarean
and vaginal delivery, excess intravenous hydration is poorly tolerated.
1. Ross A. Physiological Changes of Pregnancy. In Birnbach DJ, Gatt SP, Datta S.(eds) Text book of Obstetric Anesthesia. Churchill Livingstone, Philadelphia, PA. 2000:34-39.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
209
199. C (2,4) Resolves spontaneously within several days Has higher incidence with lidocaine spinal and lithotomy position Prospective, randomized, controlled studies reveal up to a 40% incidence of pain radiating
from the lower back to the buttocks or lower extremities after lidocaine spinal anesthesia.
These symptoms have been labeled transient neurological symptoms (TNS) and also have
been reported with other local anesthetics, but it is clear that the incidence of TNS is
greater after lidocaine spinal anesthesia. Patients typically manifest symptoms of TNS
within 12 to 24 h after surgery. The pain is characterized by back pain radiating to the legs
without sensory or motor deficits, occurring after the resolution of spinal block and
resolving spontaneously within several days. Clinical studies have identified the use of
lidocaine, lithotomy position, ambulatory surgical status, arthroscopic knee surgery, and
obesity are factors that place patients at increased risk for development of TNS.
1. Salinas FV, Liu SL, Schloz AM. Analgesics. In Evers AS, Maze M (Eds) Anesthetic pharmacology. Churchill Livingstone. Philadelphia, PA. 2004:526-7. 200. E All Clopidogrel should be discontinued for 7 days before a neuraxial anesthesia. Aspirin may be safely used in patients having epidural or spinal injections. Subcutaneous heparin does not appear to increase the risk of spinal hematoma. Post surgical prophylactic dose of low molecular weight heparin (LMWH) may be started 2-4 hours after removal of epidural catheter. It is now recommended that clopidogrel be discontinued for 7 days before a neuraxial
anesthesia or analgesia. (one case reports of epidural hematoma following clopidogrel)
Aspirin can be safely used with neuraxial injections, but caution should be observed in
patients on multiple antiplatelet medications.
Subcutaneous heparin does not appear to increase the risk of spinal hematoma, and the
risk may be further reduced by administering heparin at least one hour before the block.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
210
When prophylactic doses (30 mg BID) of low molecular weight heparin is employed
(LMWH), neuraxial blocks or catheter insertion or removal should not be performed for 12
hours. This period is increased to 24 hours when therapeutic doses of LMWH (1 mg/kg) are
employed. LMWH may be started 2-4 hours after epidural analgesia is discontinued.
1. Benzon HT< Wong HY, Siddiqui T, et al: Caution in performing epidural injections in patients on several antiplatelet drugs. Anesthesiology 1999;91:1558-1559. 2. The American Society of Regional Anesthesia and pain Medicine Consensus Conference. Regional anesthesia in the anticoagulated patient-defining the risks.2002; www.asra.com. 201. A (1,2,3) May be difficult to differentiate from chickenpox during the first 2-3 days May cause death due to toxemia and overwhelming pneumonia Vaccine consists of live attenuated vaccinia virus Differentiation between chickenpox and smallpox can be difficult during the first 2-3 days.
The most reliable differentiation is that the vesicles of smallpox are all at the same stage on
all parts of the body, while they are at different stages on different parts of the body in
chickenpox. Death may occur for hypotension, toxemia and severe pneumonia. Vaccination
within 3 days of exposure will prevent or significantly lessen the severity of the disease.
The vaccine, which consist of live attenuated vaccinia virus, may cause life threatening side
effects in 14 to 52 people per million. Vaccine offers elevated protective immunity for 5
years and diminishing effects over the next 15 years.
1. Breman JG, Henderson DA. Diagnosis and management of smallpox. N Engl J Med.2002;346:1300-1308 2. Centers of Disease Control and Prevention. Emergency preparedness and response: smallpox. Available at: http://www.bt.cdc.gov/agent/smallpox/index.asp Accessed October 20, 2003
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
211
202. B (1,3) May cause prolongation of QT interval in the ECG Has a major metabolite with potent serotonin (5HT3) receptor agonist activity
Both Dolasetron Mesylate and its major metabolite, hydrodolasetron, are potent and highly
selective serotonin (5HT3) receptor antagonists. Dolasetron Mesylate is rapidly eliminated
(t1/2 < 10 min) and completely metabolized to hydrodolasetron by a ubiquitous enzyme,
carbonyl reductase.
Dolasetron Mesylate has multiple routes of elimination- both renal and hepatic. Therefore,
there is no need for dosage adjustment in patients with impaired renal and/or hepatic
function. The majority of hydrodolasetron is excreted in the urine unchanged.
Dolasetron Mesylate can cause ECG interval changes (PR, QT, JT prolongation and QRS
widening). These changes are self-limiting with declining blood levels.
1. Hahne W, Pharmacology and metabolism of Dolasetron Mesylate. Eur Hosp. Pharmacy. 1996;2(Suppl 1):S12-S14. 2. Kuryshev YA, Brown AM, Wang L, Benedict CR, Rampe D. Interactions of the 5-hydroxytryptamine 3 antagonist class of antiemetic drugs with human cardiac ion channels. J Pharmacol Exp Ther. 2000 Nov;295(2):614-20. 203. A (1,2,3) Is an indirectly acting sympathomimetic amine Has four stereoisomers Is superior to other vasopressors in preserving uteroplacental blood flow Ephedrine is an indirectly acting sympathomimetic amine with some degree of direct action
on adrenoceptors. The major mechanism of its indirect action is considered to be release of
norepinephrine from peripheral sympathetic neurons and, possibly, inhibition of neuronal
norepinephrine reuptake, rather than a centrally mediated action.
Because ephedrine contains two asymmetrical carbon atoms, four stereoisomers of
ephedrine are present l-ephedrine, d-ephedrine, l-pseudoephedrine, and d-
pseudoephedrine. Among these only d-ephedrine is used as a vasopressor and d-
pseudoephedrine is used as a nasal decongestant.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
212
Ephedrine is used as the first-line vasopressor to treat hypotension associated with regional
anesthesia in obstetrics. This is because of its ability to preserve utero-placental blood flow
compared with other vasopressors. Uteroplacental circulation lacks (or has reduced)
sympathetic innervation. Since ephedrine exerts its pressor response via norephinephrine
release from sympathetic nerve terminals, it does not produce any contraction in human
umbilical artery or vein.
1. Kobayashi S, Endou M, Sakuraya F et al. The sympathomimetic action of l-ephedrine and d-pseudoephedrine: Direct receptor activation or norepinephrine release? Anesthe Analg 2003;97:1239-45 204. A (1,2,3) Provides extended period of slow drug administration In febrile patients may increase fentanyl absorption Achieves therapeutic levels within 6-8 hours Transdermal fentanyl patch is especially useful in chronic pain patients since it can provide
extended slow drug administration similar to that provided with a continuous intravenous
infusion.
In adults, uptake of fentanyl begins within 1 hour, achieving therapeutic level within 6-8
hours and peak levels at 18-24 hours. The skin acts as a reservoir, and, even after removal,
uptake continues for some hours. The fentanyl uptake is markedly affected by skin blood
flow, and alteration in skin blood flow, such as those caused by fever, may increase
absorption.
1. Cote CJ, Lugo RA, Ward RM.Pharmacokinetics and pharmacology of drugs in children. In Corte CJ, Tordes ID, Ryan JF, Goudsouzian NG (Eds)A Practice of Anesthesia for Infants and Children. 3rd ED. W.B Saunders, Philadelphia, PA. 2001:149
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
213
205. A (1,2,3) Supplemental oxygen Positive end-expiratory pressure (PEEP) Inhalation of beta-2-agonists Hypoxemia is the most common clinical manifestation of aspiration pneumonitis.
The most effective treatment is supplemental oxygen and institution of PEEP. Beta-2
agonists effectively relieve bronchospasm. Gastric fluid is rapidly distributed to the
periphery of the lung and lavage with large volumes of fluid could exaggerate this process.
1. Restrictive Lung Disease. Stoelting RK, Dierdorf SF.(eds) Anesthesia and Co-existing Disease. 4th edition. Churchill Livingstone, Philadelphia, PA. 2002:208. 206. D (4) Can be measured using body plethysmography The FRC is defined as the volume of gas in the lung at the end of a normal expiration when
there is no airflow and alveolar pressure equals ambient pressure.
FRC equals the residual volume plus the expiratory reserve volume (not inspiratory reserve
volume). Residual volume cannot be measured by simple spirometry. Therefore the three
methods used for measurement of FRC are Nitrogen washout, Helium washing and body
plethysmography.
1. Benumof JL. Respiratory physiology and respiratory function during anesthesia. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:590
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
214
207. B (1,3) Is a sensitive test of early small airway disease Is measured by the use of a tracer gas such as Xenon-133 (Xe133) Closing volume (CV) is the volume at which smaller airways begin to close during expiration
and CV plus the residual volume is known as the closing capacity (CC). Smoking, obesity,
aging, and the supine position increase the CC.
Closing capacity is a sensitive test of early small airway disease. Measurement of CC is
done by the use of a tracer gas such as xenon-133.
The relationship between FRC and CC is far more important than consideration of the FRC
or CC alone because it is this relationship that determines whether a given respiratory unit
is normal or atelectatic or has a low V/Q ratio. When the volume of lung at which some
airways close is greater than the whole of the tidal volume, lung volume never increases
enough during tidal inspiration to open any of these airways. Thus, these airways stay
closed during the entire tidal breathing. Airways that are closed all the time are equivalent
to atelectasis.
1. Benumof JL. Respiratory physiology and respiratory function during anesthesia. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:592-3 208. A (1,2,3) Decreases significantly with the induction of general anesthesia. Reduction correlates with an increase in alveolar-arterial PO2 gradient during anesthesia (A-a gradient). Remains decreased into the postoperative period. Induction of general anesthesia is consistently accompanied by a significant (15-20%)
decrease in FRC. The maximum decrease in FRC appears to occur within the first few
minutes of anesthesia and in the absence of any other complicating factors does not seem
to decrease progressively during anesthesia. The reduction of FRC continues into the
postoperative period. For individual patients, this reduction correlates well with an increase
in A-a gradient during anesthesia.
1. Benumof JL. Respiratory physiology and respiratory function during anesthesia. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:604
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
215
209. E All Deliberate hypotension Positive end expiratory pressure (PEEP) Pulmonary embolism Increase in airway pressure Little or no zone 1 exists in the lung under normal conditions because the normal
pulmonary artery pressure (Ppa = 30 cm H2O) is greater than the height of a water column
between the heart and top the lung (about 15 cm); but the amount of zone 1 lung may be
greatly increased if Ppa (pulmonary artery pressure) is reduced or alveolar pressure is
increased.
A decrease in pulmonary artery pressure, as during deliberate hypotension during
anesthesia, increase in alveolar pressure as with PEEP, or pulmonary embolus may increase
the amount of lung that is ventilated but under perfused (increase in Zone 1).
1. Benumof JL. Respiratory physiology and respiratory function during anesthesia. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:610 2. Powell FL. Structure and Function of the Respiratory System. In Johnson LR (Ed) Essential Medical Physiology. Lippincott Williams & Wilkins, Philadelphia, PA.1998:250 210. A (1,2,3) Increased QT interval Rise in plasma potassium Increased myocardial oxygen demand The effects of CO2 on the cardiovascular system are as complex as those of hypoxia. Like
hypoxemia, hypercapnia appears to cause direct depression of both the cardiac muscle and
vascular smooth muscle, but at the same time it causes reflex stimulation of the
sympathoadrenal system. With moderate to severe hypercapnia, a hyperkinetic circulation
results with increased QT and systemic blood pressure. Thus hypercapnia like hypoxia may
cause increased myocardial O2 demand (tachycardia, early hypertension) and decreased
myocardial O2 supply (tachycardia, late hypotension). Hypercapnia is a potent pulmonary
vasoconstrictor.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
216
Hypercapnia is accompanied by a leakage of potassium from the cells into the plasma.
Much of the potassium comes from the liver, probably from glucose release and
mobilization, which occur in response to the rise in plasma catecholamine levels. Because
the plasma potassium levels take an appreciable time to return to normal, repeated bouts
of hypercapnia at short intervals result in a stepwise rise in plasma potassium.
1. Benumof JL. Respiratory physiology and respiratory function during anesthesia. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:613-4. 211. E All Malignancy is the underlying cause in 90% cases Dyspnea and headache are the most common symptoms Patient may present with changes in mental status
Changes in voice or stridor may occur Malignancy is the underlying cause in 90% of cases of superior vena cava syndrome (SVC
syndrome). In most, causative extrinsic disease begins in the right paratracheal space or
right pulmonary hilum. Upper body venous hypertension impedes lymphatic drainage, often
leading to lymphedema or chylothorax. Dyspnea and headaches are the most common
symptoms. Changes in mental status herald the onset of cerebral edema; changes in voice
or stridor suggest laryngeal edema or recurrent laryngeal nerve injury.
1. Narang S, Harte BH, Body SC. Anesthesia for patients with a mediastinal mass. Anesthesiol Clin North America. 2001 Sep;19(3):559-79 212. E All Describes the position of the Oxy-hemoglobin curve. When lower, may require higher than normal tissue perfusion to produce the normal amount of oxygen unloading. Is lower in carbon monoxide poisoning. Is lower in methemoglobinemia. The position of the oxy-hemoglobin curve is best described by the PO2 level at which
hemoglobin is 50% saturated (P50). The normal adult P50 is 26.7 mmHg. A P50 lower than
27 mmHg describes a left-shifted oxy-Hb curve and Hb has a higher affinity for O2. This
lower P50 may require higher than normal tissue perfusion to produce the normal amount of
oxygen unloading. The causes of a left-shifted oxy-hemoglobin curve are alkalosis,
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
217
hypothermia, abnormal and fetal hemoglobin, carboxyhemoglobin, methemoglobin, and
decreased RBC 2,3-diphosphoglycerate (2,3-DPG) content.
1. Benumof JL. Respiratory physiology and respiratory function during anesthesia. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:596 213. E All Is stimulated by increases in intravascular volume Causes increased heart rate Sends afferent impulses through vagus nerve Has its receptors within the right atrial wall Bainbridge reflex responds to changes in right atrial or central venous pressure via stretch
receptors present within the right atrial wall and cavoatrial junction. Increases in
intravascular volume or right-sided filling pressures stimulate these receptors and send
their impulses through vagal afferent to inhibit parasympathetic activity and to increase
heart rate. In addition there is also a direct stretching effect on the SA node, which also
leads to enhanced automaticity and increase heart rate.
1. Blanck TJ, Lee DL. Cardiac physiology. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:641 214. A (1,2,3) Responds to changes in blood pressure via stretch receptors present in the carotid sinus and aortic arch. Sends impulses along the afferent limbs of glossopharyngeal and vagus Typically begins to respond at pressures in excess of 170 mmHg. The baroreceptor reflex (carotid sinus reflex) responds to changes in blood pressure
(typically >170 mmHg increase) via circumferential and longitudinal stretch receptors
present in the carotid sinus and aortic arch. The impulses are sent along the afferent limbs
of glossopharyngeal and vagus nerve. The response is decreased sympathetic activity-
decreased contractility, heart rate, and vascular tone, and increased parasympathetic
activity. Decreases in blood pressure have the reverse effect but at pressures lower than
50-60 mmHg baroreceptors lose much of their functional capacity.
1. Blanck TJ, Lee DL. Cardiac physiology. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:641
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
218
215. B (1,3) Is principally driven by mean arterial pressure Exhibits some degree of autoregulation Coronary blood flow (CBF), like blood flow in other vessels, is principally driven by mean
arterial pressure. CBF through the left side is maximal during early diastole, corresponding
to the period of isovolumic relaxation and minimum extravascular compression. CBF
through the right side is maximal during peak systole, because developed pressure and
consequently extravascular compression within the RV are considerably less than in the LV.
Coronary arteries exhibit some degree of autoregulation like the renal and carotid arteries
and maintain CBF within tightly controlled limits over a perfusion pressure range of 0 to
140 mmHg.
1. Blanck TJ, Lee DL. Cardiac physiology. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:642-3 216. B (1,3) A VVIR pacemaker senses electrical activity only in the ventricle An AOO pacemaker is a fixed rate pace maker The pacemaker code consists of 5 letters. The first three letters describes the anti
bradycardic function, the fourth addresses the rate responsive feature, and the fifth
describes the antitachycardia function.
First letter: Identifies which chamber(s) of the heart are paced by the pace maker-A
(atrium), V (ventricle), and D (both)
Second letter: Refers to which chamber is sensed for electrical activity. (A/V/D or O for no
sensing)
Third letter: Describes the pacemaker’s response to sensed electrical activity. O for no
response; I refers to inhibited; T to triggered; D for dual triggered and inhibited.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
219
Fourth letter: R is used to indicate the presence of a rate responsive feature or ability to
increase heart rate based on the body’s metabolic demand.
Fifth letter: Is rarely used and indicates the response of the pacemaker to detected
tachycardia.
VVIR pacemaker senses electrical activity only in the ventricle. R indicates that the
pacemaker has a rate responsive capability.
VVD pacemaker can only pace in the ventricle; it can sense electrical activity in both the
atrium and the ventricle.
AOO is a fixed rate pacemaker and cannot serve any intrinsic electrical activity.
When AAI pacemaker senses an intrinsic electrical beat in the atrium, it inhibits the
generator from firing.
1. Moses H, Miller B, Moulton K, Schneider J. A Practical Guide to Cardiac Pacing. 5th edition Philadelphia: Lippincott Williams & Wilkins. 2000. 217. E All Battery failure Hyperkalemia Myocardial ischemia Severe hyperglycemia Failure to capture may be caused by
a) An increase in fibrotic tissue at the site of lead implantation
b) Fracture of the pacemaker leads
c) Disconnection between the pacemaker lead and the generator
d) Battery failure
e) Metabolic changes that change the effective threshold for capture-
hyperkalemia, severe hyperglycemia, hypercarbia or hypoxia
f) Medications- beta blockers, amiodarone, procainamide
g) Myocardial ischemia and myocardial infarction 1. Sarko J, Tiffany B. Cardiac pacemakers: Evaluation and management of malfunctions. Am J Emerg Med 2000;18(4):435-440.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
220
218. E All Causes platelet dysfunction Directly impairs enzymes of the coagulation cascade Impairs immune function Decreases wound oxygen delivery Coagulation is impaired by mild hypothermia. The most important factor appears to be a
cold-induced defect in platelet function. Hypothermia also directly impairs enzymes of the
coagulation cascade. This may not be apparent during routine coagulation screening
because the tests are performed at 37oC.
Hypothermia can contribute to wound infection both by directly impairing immune function
and by triggering thermoregulatory vasoconstriction that, in turn, decreases wound oxygen
delivery.
1. Sessler DI. Temperature Monitoring. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:1376-77. 219. E All Increases oxygen consumption about 100% Increases intraocular pressure Can be treated by skin surface warming Increases intracranial pressure Postanesthetic shivering is a potentially serious complication, increasing oxygen
consumption roughly 100%, in proportion to intraoperative heat loss. In addition to
increasing intraocular and intracranial pressures, postoperative shivering also likely
aggravates wound pain by stretching incisions.
Postanesthetic shivering can be treated by skin surface warming because the regulatory
system tolerates more core hypothermia when cutaneous warm input is augmented. This
technique is effective in most patients with core temperatures exceeding 35oC.
1. Sessler DI. Temperature Monitoring. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:1378.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
221
220. A (1,2,3) Operating room temperature is the most crucial factor influencing heat loss One cotton blanket placed on the patient reduces heat loss by about 30% The most effective perianesthetic warming system is forced air warming blanket Operating room temperature is the most crucial factor influencing heat loss because it
determines the rate at which metabolic heat is lost by radiation and convection from the
skin and by evaporation from within surgical incisions.. However room temperature > 23oC
in adults and > 26oC in infants generally are required to maintain normothermia. The
easiest method of decreasing cutaneous heat loss is to apply passive insulation to the skin.
A single layer of cotton blankets, surgical drapes and plastic sheeting reduces heat loss
approximately 30%.
Studies consistently report that circulating-water mattresses are nearly ineffective.
Furthermore, the combination of heat and decreased local perfusion (due to patient’s
weight reducing capillary blood flow) increases the propensity for burns even when water
temperature does not exceed 40o C.
The most effective perianesthetic warming system is forced air and has been shown to
maintain normothermia even during the largest operations.
1. Sessler DI. Temperature Monitoring. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:1380-81 221. B (1,3) Is employed to reduce the need for allogenic red blood cells May improve tissue perfusion The term acute normovolemic hemodilution (ANH) refers to the removal of blood from the
surgical patient immediately before or just after induction of anesthesia, replacement with
asanguinous fluid, and later reinfusion of the withdrawn blood. ANH is employed to reduce
the need for allogenic red blood cells and to avoid potential transfusion associated
complications. An additional potential advantage of ANH is improvement in tissue perfusion
as a result of decreased viscosity.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
222
The presence of malignancy or wound infection may contraindicate blood recovery during
surgery, but not ANH.
1. Stehling L. Autologous Transfusion. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:1649-50 222. E All Air and fat embolism Rh isoimmunization during cesarean deliveries Renal dysfunction secondary to lysis of red blood cells Disseminated intravascular coagulation Potential complications associated with use of the cell processing devices include air and fat
embolism, pulmonary dysfunction secondary to infusion of debris in recovered blood,
coagulopathy, renal dysfunction, sepsis and dissemination of malignant cells. Lysis of red
blood cells can occur as a result of high vacuum suction levels or aspiration techniques that
cause turbulence during blood collection. Two cases of renal dysfunction requiring dialysis
have been reported.
Processed blood is depleted of coagulation proteins and functional platelets. There is a
report of two cases of disseminated intravascular coagulation in patients undergoing spine
surgery during which recovered blood was reinfused.
Transfusion of red blood cells salvaged during cesarean section can result in the
administration of a substantial additional load of fetal erythrocytes. Antigens present on
fetal erythrocytes but absent on maternal erythrocytes can result in alloimmunization
(especially Rh isoimmunization). Therefore, immunoglobulin should be administered as
necessary.
1. Stehling L. Autologous Transfusion. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:1654-5 2. Weiskopf RB. Erythrocyte salvage during cesarean section. Anesthesiology. 2000;92:1519-22
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
223
223. A (1,2,3) Hemorrhage accounts for more than 25% of maternal deaths. In the United States, maternal deaths due to anesthesia related Complications have decreased within the last twenty years. Maternal case-fatality risk ratio for general anesthesia has shown to be 16 Times that of regional anesthesia after 1985. Maternal hemorrhage, the leading cause of maternal mortality, accounts for 25% of
maternal mortality in the developing world, just as it does in the developed world.
In the United States, the anesthesia related maternal mortality rate (deaths per million live
births) has decreased in each subsequent 3 year period from 4.3 per million in 1979-1981
to 1.7 per million in 1988 - 1990. Since 1984, the number of deaths involving general
anesthesia have remained stable, but the number of regional anesthesia –related deaths
have decreased. The case-fatality risk ratio for general anesthesia was 2.3 times that for
regional anesthesia before 1985, but increased to 16.7 times that after 1985.
1. Thomas T. Maternal Mortality. In Birnbach DJ, Gatt SP, Datta s, editors. Textbook of Obstetric anesthesia 2000. Churchill Livingstone Philadelphia, PA. 2000:35 2. Hawkins JL, Koonin LM, Palmer SK, Gibbs CP. Anesthesia-related deaths during obstetrics delivery in the United States, 1979-1990. Anesthesiology 1997;86:277-84 224. A (1,2,3) Developmentally, is a paired structure May have midline gaps due to lack of fusion in the mid-line Is thinnest at the cervical and high thoracic levels The ligamentum flavum is a structure composed of elastic fibers. In contrast to the
ligamentum flavum, supraspinous and interspinous ligaments are composed of collagenous
fibers.
Developmentally, the ligamentum flavum is a paired structure and gaps due to lack of
fusion in the midline has been demonstrated. Absence of continuous ligamentum flavum
may imply that actual loss of resistance is brought about by supraspinous and interspinous
ligaments. Therefore, distinct elastic resistant offered by the ligamentum flavum may be
blunted or even absent, in these situations. These gaps are shown to be frequent at the
cervical and high thoracic levels but become rare at the T3/T4 level and below.
1. Lirk P, Kolbitsch C, Putz G, et al. Cervical and high thoracic ligamentum flavum frequently fails to fuse in the midline. Anesthesiology 2003;99:1387-90.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
224
225. D (4) Total uterine blood flow approaches 800 ml/min The total uterine blood flow increases during pregnancy and approaches 800 ml/min; 80%
of which reaches the intervillous space for interfacing with the fetal circulation, while the
remaining 20% supplies the uterine myometrium. The uterine vascular bed is almost
maximally dilated under normal conditions. The uterine blood flow is not autoregulated and
is proportional to the mean perfusion pressure.
Uterine blood flow = uterine arterial pressure - uterine venous pressure / uterine vascular
resistance
The sensitivity to alpha-adrenergic agonists in the uterine circulation is maintained and in
fact, uterine vessels become more sensitive to alpha agonists than are the systemic
vessels. Accordingly, excessive administration of vasopressors with predominantly alpha-
adrenergic action may impair uterine blood flow.
1. Alahuhta S. Uteroplacental blood flow. In Birnbach DJ, Gatt SP, Datta s, editors. Textbook of Obstetric anesthesia 2000. Churchill Livingstone Philadelphia, PA. 2000:62 226. B (1,3) Acts by increasing cyclic guanosine monophosphate May be potentiated by Sildenafil, phosphodiesterase-5 inhibitor Nitric oxide used as an inhaled gas is a selective pulmonary vasodilator and there is no
systemic vasodilatation and hypotension. It acts by stimulating soluble guanylate cyclase
and increasing cyclic guanosine monophosphate. The effect of inhaled nitric oxide may be
potentiated by phophodiesterase-5 inhibitors (e.g. dipyridamole and sildenafil) which
specifically suppress cyclic guanosine monophosphate catabolism and prolong its action.
Sildenafil has been described in case reports as a therapy for severe pulmonary
hypertension.
1. Blaise G, Langleben D, Hubert B. Pulmonary arterial hypertension, pathophysiology and anesthetic approach. Review article. Anesthesiology 2003;99:1415-32 2. Prasad S, Wilkinson J, Gatzoulis MA. Sildenafil in primary pulmonary hypertension (letter). N Eng J Med 2000;343:1342
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
225
227. A (1,2,3) Metabolic acidosis Respiratory acidosis Decreased extracellular concentration of potassium Both metabolic and respiratory acidosis may augment a nondepolarizing neuromuscular
blockade. Low extracellular concentration of potassium (especially acute decrease)
increases the transmembrane potential, causing hyperpolarization of cell membranes. This
manifests as resistance to the effects of depolarizing drugs and increased sensitivity to
nondepolarizing neuromuscular blocking drugs. Hyperkalemia has the opposite effects,
increasing the effects of depolarizing drugs and opposing the action of nondepolarizers.
Administration of antibiotics particularly aminoglycosides and polypeptide classes may
enhance the blockade. Antibiotics devoid of neuromuscular blocking effects are the
penicillins and cephalosporins.
1. Savarese JJ, Caldwell JE, Lien CA, Miller RD. Pharmacology of muscle relaxants and their antagonists. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:468-9. 2. Neuromuscular Blocking drugs In Stoelting RK (editor) Physiology & Pharmacology in Anesthetic Practice. Third edition. Lippincott Williams & Wilkins, Philadelphia, PA. 1999:197. 228. E All Respiratory acidosis (PaCO2 greater than 50 mmHg) Hypothermia Low extracellular potassium concentration Magnesium sulfate Antagonism of neuromuscular blockade by anticholinesterase drugs may be inhibited or
even prevented by (a) certain antibiotics, (b) hypothermia, (c) respiratory acidosis
associated with a PaCO2 of > 50 mmHg, (d) magnesium sulfate, or (e) hypokalemia and
metabolic acidosis.
Magnesium sulfate, given for the treatment of preeclampsia, enhances the neuromuscular
blocking properties of both non depolarizers and depolarizers. Magnesium decreases the
amount of Ach released from the motor nerve terminal, the depolarizing action of Ach on
the postjunctional membrane, the excitability of the muscle fiber itself, and the amplitude
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
226
of the action potential. Therefore, there is reduced Ach output and reduced sensitivity of
the postjunctional membrane.
1. Neuromuscular blocking drugs. In Stoelting RK (editor) Physiology & Pharmacology in Anesthetic Practice. Third edition. Lippincott Williams & Wilkins, Philadelphia, PA. 1999:197. 2. Savarese JJ, Caldwell JE, Lien CA, Miller RD. Pharmacology of muscle relaxants and their antagonists. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:463.. 229. E All Has less muscarinic effects Has a quicker onset of action Has fewer side effects Is not broken down by acetylcholinesterase In patients with normal renal and hepatic function, there are no significant pharmacokinetic
differences among the anticholinesterase drugs. Controlled studies in anesthetized patients
have documented that the duration of action of edrophonium does not differ from that of
neostigmine. Elimination half-life of edrophonium (110 min) is similar to that of
pyridostigmine (113 min) and neostigmine (77 min). Edrophonium has a quicker onset of
action and fewer side effects. The muscarinic effects of edrophonium are mild compared
with neostigmine.
Neostigmine inhibits the breakdown of acetylcholine by virtue of it being hydrolyzed by
acetylcholinesterase. In this process, acetylcholinesterase is carbamylated, and its ability to
hydrolyze acetylcholine is decreased. In contrast to neostigmine, acetylcholinesterase does
not break down edrophonium but rather edrophonium forms a reversible electrostatic
attachment to the enzyme.
1. Savarese JJ, Caldwell JE, Lien CA, Miller RD. Pharmacology of muscle relaxants and their antagonists. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:470. 2. Neuromuscular Blocking drugs In Stoelting RK (editor) Physiology & Pharmacology in Anesthetic Practice. Third edition. Lippincott Williams & Wilkins, Philadelphia, PA. 1999:226-8..
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
227
230. E All The sensitivity to non depolarizers may be diminished The response to succinylcholine may be lengthened The reversal of residual block at the end of the case may be ineffective Often surgical relaxation can be provided using a potent inhaled anesthetic only Pyridostigmine will modify the response to relaxants and the sensitivity to non-depolarizers
will be diminished. The response to succinylcholine may be lengthened because therapeutic
levels of pyridostigmine may partially inhibit pseudocholinesterase. The reversal of non-
depolarizers may be ineffective because much acetylcholinesterase inhibition already exist.
Therefore, it is probably safer to allow spontaneous recovery postoperatively while
continuing mechanical ventilation.
1. Savarese JJ, Caldwell JE, Lien CA, Miller RD. Pharmacology of muscle relaxants and their antagonists. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:471 231. B (1,3) The duration of mivacurium may be lengthened due to decrease in the plasma cholinesterase activity The duration of action of atracurium is not affected by renal failure Renal failure influence the pharmacology of nondepolarizing muscle relaxants by producing
either decreased elimination of the drug or its metabolites via the kidney, or decreased
activity of enzymes that metabolize the drug (e.g., mivacurium). Renal failure can decrease
plasma cholinesterase activity, and mivacurium is metabolized by plasma cholinesterase at
approximately 70% of the rate of succinylcholine.
The pharmacokinetics and the duration of action of atracurium are unaffected by renal
failure, because atracurium undergoes spontaneous chemical degradation and ester
hydrolysis. The elimination half-life of laudanosine, the principal metabolite of atracurium,
increases significantly in renal failure.
Although the plasma clearance is unchanged in renal failure, the volume of distribution of
rocuronium is increased by 28% and elimination half life is prolonged by 37%.
1. Savarese JJ, Caldwell JE, Lien CA, Miller RD. Pharmacology of muscle relaxants and their antagonists. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:458
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
228
232. B (1,3) Decreasing the amount of acetylcholine (Ach) released from the motor nerve terminal Decreasing the excitability of the muscle fiber itself Magnesium decreases the amount of acetylcholine (Ach) released from the nerve terminal,
the depolarizing action of the Ach on the postjunctional membrane, the excitability of the
muscle fiber itself and the amplitude of the end-plate potential.
A prolonged block should be anticipated when a muscle relaxant is administered to a
patient receiving magnesium.
1. Savarese JJ, Caldwell JE, Lien CA, Miller RD. Pharmacology of muscle relaxants and their antagonists. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:463 233. B (1,3) Local anesthetics Dantrolene In large doses and given intravenously, most local anesthetics block neuromuscular
transmission; in smaller doses, they enhance the neuromuscular block from both
nondepolarizing and depolarizing muscle relaxants.
Dantrolene depresses skeletal muscle directly and also blocks excitation-contraction
coupling; the effects of nondepolarizing muscle relaxants are enhanced.
Chronic phenytoin or carbamazepine therapy accelerates recovery from nondepolarizing
muscle relaxants; the mechanism of this relative resistance is not clear.
1. Savarese JJ, Caldwell JE, Lien CA, Miller RD. Pharmacology of muscle relaxants and their antagonists. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:464
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
229
234. B (1,3) Disruption of sodium channel activation process Blockade of the ion-conducting pores Local anesthetics do not alter the resting membrane potential or the threshold level, but it
slows the rate of depolarization by inhibition of the sodium channels
There are 2 fundamental mechanisms of inhibition:
(1) Na+ currents are reduced by the local anesthetics primarily because the drug-
bound channels fail to open; channel activation process is disrupted by local
anesthetics. A sodium channel inhibited by local anesthetic is functionally similar
to an inactivated channel.
Local anesthetics bind more rapidly and with higher affinity to activated
channels (open or preceding the open state) than to resting channels.
Regardless of the channel state, by its very binding the local anesthetic
stabilizes that state.
(2) Blockade of ion-conducting pore, contribution from this action seems minor.
1. Berde CB, Strichartz GR. Local Anesthetics In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:498-50 235. E All Ester local anesthetics are relatively unstable in solution Amide compounds undergo enzymatic degradation in the liver Reports of allergic reactions to amide compounds are extremely rare Amide local anesthetics are extremely stable in solution The ester and amide local anesthetics differ in their chemical stability, locus of
biotransformation, and allergic potentials.
Amino esters are hydrolyzed in plasma by the cholinesterase enzymes, except cocaine. P-
aminobenzoic acid is one of the metabolites of ester type compounds that can induce
allergic-type reactions in a small percentage of patients.
1. Berde CB, Strichartz GR. Local Anesthetics In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:501-2.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
230
236. E All Rate of injection Hypercarbia Metabolic acidosis Site of injection The rate of injection and the rapidity with which a particular blood level is achieved
(vascularity of the site of injection) alter the toxicity of local anesthetic drugs. Respiratory
and metabolic acidosis increases the risks of local anesthetic toxicity. An elevation of PaCO2
enhances cerebral blood flow and anesthetic is delivered more rapidly to the brain. In
addition, diffusion of carbon dioxide into the neuron cells decreases the intracellular pH, so
that ion trapping occurs. Hypercarbia and/or acidosis also decrease the plasma protein
binding of local anesthetic drugs. This increases the free drug available for diffusion into
the brain.
1. Berde CB, Strichartz GR. Local Anesthetics In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:511. 237. B (1,3) Venodilatation Hypotension which is greater in hypertensive patient than in normotensive patients The predominant cardiovascular effect of barbiturate induction is venodilatation, followed
by pooling of blood in the periphery. Myocardial contractility is depressed, but not to the
extent seen after volatile anesthetics.
Both thiopental and methohexital cause an increased heart rate. Therefore, must be used
cautiously if at all in conditions in which an increased heart rate or a decrease in preload
could be detrimental (pericardial tamponade, ischemic heart disease, hypovolemia,
congestive heart failure). Heart rate increases more after methohexital than after
equivalent dose of thiopental.
Hypotension from a given dose is greater in both treated and untreated hypertensive
patients than in normotensive patients.
1. Fragen RJ, Avram MJ, Barbiturates. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:509.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
231
238. E All Vecuronium Atracurium Sufentanil Midazolam The pH of thiopental solution is 10-11. A decrease in the alkalinity of the barbiturate
solution can result in their precipitation as free acids. The drugs that are in more acidic
solutions when co-administered with thiopental have the potential to precipitate and
occlude the intravenous line. These include pancuronium, vecuronium, atracurium,
sufentanil and midazolam. Such precipitation can be prevented by allowing a 30-second
delay between the injection of thiopental and the injection of other drugs.
1. Fragen RJ, Avram MJ, Barbiturates. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:509. 239. C (2,4) May cause hypotension After discontinuation most drug effects are eliminated within 5 minutes Esmolol is a potent selective beta-1-receptor antagonist. It may cause hypotension through
both vasodilatation and negative inotropic effect. Esmolol is rapidly hydrolyzed by esterases
in the cytosol of red blood cells (not plasma esterases) resulting in an elimination half life of
9 minutes.
1. Balser JR, Butterworth J. Cardiovascular drugs. In Hensley FA,jr, Martin DE, Gravlee GP (eds) A Practical Approach to Cardiac Anesthesia. 3rd edition. Lippincott Williams & Wilkins, Philadelphia, PA. 2003:93. 240. B (1,3) Tachyphylaxis Metabolic acidosis Nitroprusside has a rapid onset of action and a short duration of effect because of the rapid
breakdown break down of the unstable nitroprusside radical to produce cyanide. Free
cyanide ions are usually converted to thiocyanate in the liver and kidney. Free cyanide not
converted to thiocyanate can bind with high affinity to cytochrome oxidase, interfere with
electron transport, prevent cellular aerobic respiration, and produces tissue hypoxia.
Prolonged administration of nitroprusside at moderate doses may result in cyanide and
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
232
thiocyanate toxicity. During nitroprusside toxicity, there is metabolic acidosis and elevated
mixed venous PO2 (due to decreased cellular O2 utilization). No cyanosis is seen because
cells cannot utilize O2, therefore O2 saturation remains high. The recommended maximum
dose of 1.5 mg/kg for acute administration or 0.5 mg/kg/h (8 µg/kg/min) for chronic
administration appear to be safe.
1. Balser JR, Butterworth J. Cardiovascular drugs. In Hensley FA,jr, Martin DE, Gravlee GP (eds) A Practical Approach to Cardiac Anesthesia. 3rd edition. Lippincott Williams & Wilkins, Philadelphia, PA. 2003:93. 2. Aken HV, Miller ED. Deliberate Hypotension. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:1476. 241. C (2,4) Reflex bradycardic response is absent after carotid sinus massage Response to laryngoscopy may be delayed or blunted The cardiac autonomic plexus is transected during orthotopic cardiac transplantation,
leaving the transplanted heart completely denervated. Partial efferent sympathetic neuronal
reinnervation commences within 12 months of cardiac transplantation. Parasympathetic
reinnervation is much less extensive, resulting in a characteristic high resting heart rate
(HR 90-110 bpm) and absent reflex bradycardic response after carotid massage. The
transplanted heart increases cardiac output (CO) primarily by increasing stroke volume
(SV), in contrast to the normal heart. As acute changes in CO, HR, and SV in the
transplanted heart are mediated mainly by adrenal secretion and circulation of direct acting
catecholamines, the response to stressful stimuli may be delayed or blunted.
1. Rother AL, Collard CD. Anesthetic management for cardiac transplantation. In Hensley FA,jr, Martin DE, Gravlee GP (eds) A Practical Approach to Cardiac Anesthesia. 3rd edition. Lippincott Williams & Wilkins, Philadelphia, PA. 2003:442-3.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
233
242. E All No change in heart rate with administration of atropine and glycopyrrolate Increased response to epinephrine and norepinephrine Absent reflex bradycardia or tachycardia in response to changes in systemic arterial blood pressure Reduced response to alpha-adrenergic agents Autonomic denervation of the transplanted heart significantly alters the pharmacodynamic
activity of many drugs. Drugs that mediate their actions through the autonomic nervous
system are generally ineffective in altering heart rate and contractility, although partial
reinnervation may explain individual variation. Directly acting catecholamines, such as
norepinephrine and epinephrine on the other hand, show an increased response. Response
to alpha-adrenergic agents may be reduced. Reflex bradycardia or tachycardia in response
to changes in systemic blood pressure is absent. Atropine and glycopyrrolate will not alter
heart rate, although their peripheral ani cholinergic activity remains unaffected.
1. Rother AL, Collard CD. Anesthetic management for cardiac transplantation. In Hensley FA,jr, Martin DE, Gravlee GP (eds) A Practical Approach to Cardiac Anesthesia. 3rd edition. Lippincott Williams & Wilkins, Philadelphia, PA. 2003:442-3. 243. E All Is a direct vasoconstrictor Enhances the pre junctional release of norepinephrine from the adrenergic nerve ending Increases efferent sympathetic nerve activity Stimulates the secretion of aldosterone The juxtaglomerular cells of the renal cortex secrete rennin, which cleaves angiotensinogen
(produced in the liver) to form angiotensin I. Angiotensin I is converted almost immediately
to angiotensin II by ACE (angiotensin converting enzyme). ACE is found predominantly in
the endothelial cells of the lung. In addition to its direct vasoconstrictive activity,
angiotensin II enhances the pre junctional release of norepinephrine from the adrenergic
nerve ending and increases efferent sympathetic nerve activity. Angiotensin II also affects
sodium water homeostasis by increasing ADH and stimulating the secretion of aldosterone.
1. Moss J, Renz CL. The Autonomic Nervous System. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:562.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
234
244. A (1,2,3) Bradycardia with changes in position Hyperthermia easily Hypothermia easily In patients with high spinal cord transection, the only intact efferent component of
baroreflex pathway is the vagus. Therefore, bradycardia occurs with changes in position,
Valsalva maneuvers or increased thoracic pressure.
There is an increase in sensitivity to exogenously administered angiotensin as well as
catecholamines, possibly due to the impairment of descending inhibitory pathways.
Hypothermia may occur readily from cutaneous vasodilatation and the inability to shiver.
Similarly, hyperthermia can occur because the normal sweating mechanisms can be
impaired.
1. Moss J, Renz CL. The Autonomic Nervous System. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:568-9. 245. E All Inadequate corticosteroid coverage can cause death Administration of supraphysiologic doses of steroid for a short time perioperatively causes no discernible complications. Even topical application of steroid can suppress normal adrenal response for as long as 9-12 months. Plasma cortisol concentration of more than 25 µg/ml, measured during acute stress, indicates normal pituitary–adrenal responsiveness Inadequate corticosteroid coverage can lead to addisonian crisis and death. Administration
of supraphysiologic doses of steroid for a short time perioperatively causes no discernible
complications. Therefore, if in doubt supplementation should be provided to any patient
who has received steroids within a year. Even topical application of steroid can suppress
normal adrenal response for as long as 9-12 months.
The morning plasma cortisol level does not reveal whether the adrenal cortex has
recovered sufficiently. If the plasma cortisol concentration is measured during acute stress,
a value of more than 25 µg/ml indicates normal pituitary –adrenal responsiveness 1. Roizen MF .Anesthetic implications of concurrent diseases. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:921-2.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
235
246. E All Is an imidazole sedative-hypnotic Causes compromised adrenal reserves for at least 24 hours after a single induction dose Causes minimal cardiovascular depression Inhibits two essential adrenocortical
Etomidate is an imidazole sedative-hypnotic. Adrenal reserve is compromised for at least 24
hours after a single induction dose. It inhibits two essential adrenocortical hormones. There
is a dose dependent reversible inhibition of the enzyme 11-beta-hydroxylase, and a
relatively minor effect on 17-alpha-hydroxylase. It has been shown that the issue of
temporary adrenocortical suppression following induction dose of etomidate is not clinically
significant.
Etomidate causes minimal cardiovascular depression even in compromised patients. The
hemodynamic stability seen with etomidate may be due in part to its unique lack of effect
both on the sympathetic nervous system and on baroreceptor function.
1. Roizen MF .Anesthetic implications of concurrent diseases. In Miller RD (ed.): Anesthesia. 5th edition. Churchill Livingstone, Philadelphia, PA. 2000:922.
247. E All Serotonin Cholinergic Dopamine Histamine
The vomiting center is located in the lateral reticular formation of the medulla. This center
receives afferent signals from (a) the chemoreceptor trigger zone, (b) the vestibular center,
(c) higher brain stem and cortical structures, and (d) from visceral afferents such as the GI
tract. Various receptors are implicated in the stimulation of the chemoreceptor trigger zone.
These different receptors form the basis by which most current antiemetic pharmacology is
base on. These receptors are serotonin, dopamine, cholinergic (specifically muscarinic) and
histamine receptors. Antiemetic drugs such as ondansetron and dolasetron antagonize
serotonin receptors. Antidopaminergic drugs include metoclopramide and droperidol.
Antihistamine medications with antiemetic properties include promethazine and
dimenhydrinate. Finally, scopolamine represents the current anticholinergic drug in use as a
prophylactic antiemetic.
1. Evers AS, Maze M. Anesthetic Pharmacology: Physiologic Principles and Clinical Practice, Churchill Livingstone. New York NY. 2004:778-787.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
236
248. C 2,4 A - delta fiber Unmyelinated C fiber
Normal thermoregulation of body temperature is dependent on three components:
1. Afferent input from temperature sensing receptors throughout the body
2. Central regulation or control by the hypothalamus
3. Efferent responses in the form of (a) autonomic defenses such as sweating and
vasodilation for temperature increases and vasoconstriction and shivering for
decreases in temperature, and (b) behavior responses such as adding more
clothing when cold, or modifying the temperature of the environment. Of the two
responses, behavior responses are the most effective and important response.
Afferent temperature nerve fiber are primarily of two type, A - delta fibers transmit cold
sensation while unmyelinated C fibers transmit warm signals.
Below is summation of nerve fiber classification and their physiologic properties:
Type Fiber Diameter (µ) Myelination Function
A - alpha 12 - 20 Yes Proprioception, Motor
A - beta 5 - 12 Yes Proprioception, Motor
A - gamma 3-6 Yes Muscle Tone
A - delta 2 – 5 Yes Pain, Temperature, Touch
B < 3 Yes Preganglionic Autonomic
C 0.3 – 1.2 NO Autonomic, Pain, Temperature, Touch
1. Miller R. Anesthesia. 5th edition. Churchill Livingstone. New York NY. 2000:1367,494-495.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
237
249. B 1,3 Low molecular weight Low protein binding
Passive diffusion is the primary means by which medications administered to a mother
enter the fetal circulation. Factors that help promote this passive diffusion include:
1. Low molecular weight (less than 500 daltons)
2. Low protein binding
3. High lipid solubility
4. Low degree of ionization
Almost all medications used to produce anesthesia, analgesia or sedation share many of
these characteristics and readily cross the placenta. Neuromuscular relaxants however,
have low lipid solubility and high degree of ionization and therefore do not readily cross the
placenta.
1. Miller R. Anesthesia. 5th edition. Churchill Livingstone. New York NY. 2000:2031-2032.
Anesthesia Practice Questions: Book 1 – 2004 A=1,2,3 B=1,3 C=2,4 D=4 E=All
This material may not be duplicated without written permission from the publisher. Copyright 2004, All Rights Reserved Medtext Medical World, Inc. .
238
250. D 4 Usually affects children ages 2 to 6 years Epiglottitis is a life-threatening inflammation of the epiglottis secondary Haemophilus
influenzae Type b. However, since the use of a vaccine for H. influenzae type B, the
incidence of epiglottitis has decreased dramatically. Epiglottitis requires differentiation from
laryngotracheobronchitis (viral croup). At no time (in the emergency room or x-ray suite)
should direct visualization of the epiglottis be attempted in the unanesthetized patient
when epiglottitis is suspected since this may lead to complete obstruction of the airway.
Characteristics of Laryngotracheobronchitis vs. Epiglottitis
Laryngotracheobronchitis Epiglottitis Etiology Parainfluenza virus, type 1
(viral) Haemophilus influenzae, type b (bacterial)
Age Infancy 2 months-2years 2-6 years
Onset Subacute (insidious) onset Acute onset
Temperature Low grade fever High fever
Course Usually mild, stridor May worsen at night
Rapid progress of symptoms
Symptomatology Barking (croupy) cough stridor
Dysphagia, sore throat, Respiratory distress, Dysphonia (The 4 D’s – Dysphonia, Dysphagia, Drooling, Respiratory Distress)
1. Cote JC, et. al., A Practice of Anesthesia for Infants and Children. 3rd edition. Sauders. Philadelphia PA. 2001:319-321. 2. Barash P, Cullen B, Stoelting R. Clinical Anesthesia, 4th edition, J.B. Lippincott. Philadelphia PA. 2001:996-997.
Let us know your test results! We love hearing from our customers. Send a message to [email protected]
ISBN 1-889344-65-6 www.medtext.net