anesthetic preparations for surgery
TRANSCRIPT
Anesthetic Preparations For Surgery
Prepared By: Dr. Othman Ismat Abdulmajeed
Cardiac Anesthetist Hawler Medical College
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The Aim..
• Clinical Assessment..
• Anesthetic Assessment..
• What investigations we need ?
• What are the risks of having anesthesia ?
• Postoperative Care..
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Clinical Assessment
• Ideally, every patient should be seen by an anesthetist prior to surgery in order to identify, manage and minimize the anesthesia risk.
• Traditionally, this occurring when the patient was admitted, usually the day before an elective surgical procedure. However, if at this time the patient was found to have any significant co-morbidity, surgery was often postponed, and with no time to admit a different patient operating time was wasted.
• Recently, in an attempt to improve efficiency, There is a significant changes in the preoperative management including the introduction of clinics for anesthetic assessment.
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The Preoperative assessment..
A variety of models of ‘preoperative’ or ‘anesthetic assessment’ clinic exist; the following is intended to outline their principal functions:
Stage 1:-
Although not all patients need to be seen by an anesthetist in a preoperative assessment clinic, all patients do need to be assessed by an appropriately trained individual, who may take a history, examine the patient, and order investigations according to the local protocol.
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The primary aim is to identify patients who:
• have no coexisting medical problems.
• having a coexisting medical problems that is well controlled and does not impair daily activities, like hypertension.
• require only baseline investigations.
• have no history of anesthetic difficulties.
Having fulfilled these criteria, patients can then be listed for surgery. At this stage, the patient will usually be given preliminary information about anesthesia.
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On admission, these patients will need to be seen by a member of the surgical team, to ensure that there have not been any significant changes since attending the clinic, and by the anesthetist who will:
• confirm the findings from the preoperative assessment.
• check the results of baseline investigations.
• explain the options for anesthesia appropriate for the procedure.
• have the ultimate responsibility for deciding it is safe to proceed.
• obtain consent for anesthesia.
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Stage 2:-Clearly not all patients are as described in stage1, common reasons for patients not meeting the above criteria include:
• coexisting medical problems that are previously undiagnosed, for example diabetes, hypertension.
• medical conditions that are less than optimally managed, for example angina.
• abnormal baseline investigations. These patients will need to be sent for further investigations, for example ECG, PFT and ECHO, or be referred to the appropriate specialist for advice or further management before being reassessed.
The findings of the further investigations then dictate whether or not the patient needs to be seen by an anesthetist.
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Stage 3:-
Patients that will need to be seen by an anesthetist in the preoperative clinic are those who:-
1. have concurrent disease, and are symptomatic despite optimal treatment.
2. previous anesthetic difficulties, like difficult intubation. 3. have the potential for difficulties, like obesity. 4. previous or family history of apnea after anesthesia. 5. are to undergo complex surgery.
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The consultation will allow the anesthetist to:- A. make a full assessment of the patient’s medical
condition.
B. evaluate the results of investigations or advice from other specialists.
C. request any additional investigations. D. review any previous anesthetics given. E. decide on the most appropriate technique. F. begin the consent process, explaining and
documenting.
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The ultimate aim is to ensure that once a patient is admitted for surgery, their intended procedure is not cancelled as a result of them being “unfit” or because their medical condition has not been adequately investigated.
Clearly the time between the patient being seen in the assessment clinic and the date of admission for surgery cannot be excessive; 4-6 weeks is usually acceptable.
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The Anesthetic assessment
The anesthetic assessment consist of taking a history, examining each patient followed by any appropriate investigations.
When performed by non-anesthetic staff, a protocol is often used to ensure all the relevant areas are covered.
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A. Present and Past Medical History :-
Within the patient’s medical history aspects relating to the cardiovascular and respiratory systems are relatively more important to the anesthetist than the other areas.
1. Cardiovascular System:
Enquire specifically about symptoms of ischemic heart disease,heart failure,hypertension,valvular heart disease,conduction defects, Arrhythmias,peripheral vascular disease, previous (DVT) or (PE).
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Patients with a proven history of myocardial infarction (MI) are at a greater risk of further infarction perioperatively .
Heart failure is one of the most important predictors of perioperative complications.
Untreated or poorly controlled hypertension may lead to exaggerated cardiovascular responses during anesthesia. Both hypertension and hypotension can be precipitated .
The American Heart Association has produced guidance for perioperative cardiovascular evaluation.
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NYHA functional classification
Class I Cardiac disease without physical limitation
Class II Cardiac disease with slight physical limitation
Class III Cardiac disease with marked physical limitation
Class IV Cardiac disease limiting any physical activity
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New York Heart Association classification of cardiac function
2. Respiratory System: chronic obstructive pulmonary disease, chronic bronchitis, emphysema, asthma and infection.
3. Rheumatoid disease: causes limited movements of joints.
4. Diabetes: increase incidence of IHD and renal dysfunction.
5. Chronic renal failure: anemia and electrolyte disturbance.
6. Jaundice: altered drug metabolism, coagulopathy.
7. Neuromuscular disorders: poor respiratory function.
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B. Previous anesthetics and operations:-
• Ask about any perioperative problems for example nausea, vomiting, awareness, jaundice.
• Ask if any information was given postoperatively, for example difficulty with intubation, delayed recovery.
• Whenever possible, check the records of previous anesthetics to rule out or clarify problems such as difficult intubation, drug allergy.
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C. Family History:-
All patients should be asked wether any family members have experienced problems with anesthesia; for example a history of prolonged apnoea.
D. Drug History & Allergies:-
The number of medications taken rises with age. Many commonly prescribed drugs for example: B-blocker have important interactions with drugs used during anesthesia.
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The Examination
• This concentrates on the CVS and RS, The remaining systems are examined if problems relevant to anesthesia have been identified in the history.
• If a regional anesthesia is planned, the appropriate anatomy (e.g. lumbar spine for central neural block) is examined.
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• Cardiovascular System: examine for,
arrhythmias, heart failure, hypertension, valvular heart disease, peripheral vascular disease.
Don’t forget to inspect the peripheral veins to identify any potential problems with I.V. access.
• Respiratory System: examine for,
respiratory failure, atelectasis, consolidation, pleural effusion, impaired ventilation.
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• Nervous System:
Chronic disease of the central and peripheral nervous systems should be identified, and any evidence of motor or sensory impairment recorded.
• Musculoskeletal System:
Note any restriction of movement and deformity if a patient has connective tissue disorders. Patients suffering from chronic rheumatoid disease frequently have a reduced muscle mass, peripheral neuropathies and pulmonary involvement.
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The AirwayThe airway of the patient must be assessed in order to predict those patients who may be difficult to intubate.
A- Observation of the patient’s anatomy. Look for: 1. limitation of mouth opening 2. receding mandible 3. position, number and health of teeth 4. size of the tongue 5. soft tissue swelling at the front of the neck 6. limitations in flexion and extension of the cervical spine.
Finding any of these suggests that intubation may be more difficult. 21
B- Simple Bedside Test
1- Mallampati Test.
2- Thyromental Distance.
3- Calder Test: The patient is asked to protrude the mandible as far as possible. The lower incisors will lie either anterior to, aligned with, or posterior to the upper incisors. The latter two suggest a reduced view at laryngoscopy.
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Mallampati Test
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Thyromental Distance
• With the head fully extended on the neck, the distance between the bony point of the chin and the prominence of the thyroid cartilage is measured.
• A distance of <7cm suggests difficult intubation.
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Risk Associated With Anesthesia
One of the most commonly asked questions of anesthetist is “What are the risk of having an anesthetics?”.These can be divided into two groups:
1. Minor. These are not life threatening and can occur even when anesthesia has apparently been uneventful. They include:
• failed I.V. access. • cut lip, damage to teeth, caps, crowns . • sore throat. • headache. • Postoperative nausea and vomiting. • urine retention.
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2. Major Risk. These may be life-threatening events.
They include : • aspiration of gastric contents. • hypoxic brain damage. • myocardial infarction. • cerebrovascular accident • nerve injury. • chest infection. • renal failure. • death.
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Post Anesthesia Care
Each patient in the recovery unit should be cared for in an area equipped with:
• oxygen supply • ECG monitoring • Pulse oximetry • non-invasive blood pressure (NIBP) monitor • suction apparatus
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Postoperative Complications
1. Hypoxia
2. Hypotension
3. Hypertension
4. Postoperative nausea & vomiting (PONV)
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Postoperative Analgesia
Postoperative pain sequels are:
1. CVS: Tachycardia, Hypertension. 2. Respiratory: decreased of vital capacity & tidal
volume, chest infection, Basal atelectasis.
3. GIT: nausea and vomiting, ileus. 4. other effects: urinary retention, DVT, pulmonary
embolus.
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Risk Factors for PONV
• Patient Factors: Gender, Age, Anxiety, History of motion sickness, Previous PONV, Obesity, Delayed gastric emptying.
• Anesthetic Factors: a- Drugs like opioids. b- Technique like gastric insufflation. • Surgical Factors: Emergency operation, ENT surgery,
Gynecological procedures, GIT surgery, Ileus, Gastric distension.
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Sequelae of Anesthesia
• Eye trauma.
• Airway trauma.
• Musculoskeletal trauma.
• Skin damage.
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Thank you
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