middle east journal of anesthesiology · 2018-10-24 · 443..j. n 22 5, 2014 middle east journal of...

443 M.E.J. ANESTH 22 (5), 2014

Middle East Journal of Anesthesiology

Vol. 22, No. 5, June 2014

CONTENTS

EditoriAl

PrEOxygENaTiON-rOuTiNE PrEOxygENaTiON DuriNg iNDuCTiON aND rECOvEry FrOm aNESThESia iS rECOmmENDED aS a miNimal SaFETy PrECauTiON

�� Anis Baraka 445

rEviEw ArticlE

FENTaNyl-iNDuCED COugh-PaThOPhySiOlOgy aND PrEvENTiON

�� Mabelle C� Tannous El Baissari, Samar K� Taha, Sahar M� Siddik-Sayyid

449

sciEntific ArticlEs

CErEbral “hyPErOxygENaTiON” WiTh iNhalaTiONal iNDuCTiON OF aNESThESia iN ChilDrEN: a rETrOSPECTivE COmPariSON bETWEEN vaSOParalyTiC SEvOFluraNE vS. vaSONEuTral FENTaNyl

�� Deepak Gupta, Rami Bzeih, Maria Markakis Zestos 457COmPariSON bETWEEN iNTravENOuS PaTiENT CONTrOllED aNalgESia aND PaTiENT CONTrOllED

EPiDural aNalgESia iN CirrhOTiC PaTiENTS aFTEr hEPaTiC rESECTiON

��Nirmeen A� Fayed, Hatem B� Abo El-Wafa, Nahla M� Gab-Alla, Khaled A� Yassen, Mamdouh E� Lotfy

467

SimulaTiON TraiNiNg iN ENDOTraChEal iNTubaTiON iN a PEDiaTriC rESiDENCy

�� Rana Sharara-Chami, Sahar Taher, Roland Kaddoum, Hani Tamim, Lama Charafeddine

477

a SimPlE PrOTOCOl TO imPrOvE SaFETy aND rEDuCE COST iN hEmODialySiS PaTiENTS uNDErgOiNg ElECTivE SurgEry

�� Johnathan R� Renew, Sher-Lu Pai 487EmETOgENiCiTy-riSk PrOCEDurES iN SamE Day SurgEry CENTEr OF aN aCaDEmiC uNivErSiTy

hOSPiTal iN uNiTED STaTES: a rETrOSPECTivE COST-auDiT OF POSTOPEraTivE NauSEa vOmiTiNg maNagEmENT

��Deepak Gupta, Halim Haber 493ThE uSE OF airTraq laryNgOSCOPE vErSuS maCiNTOSh laryNgOSCOPE aND FibErOPTiC brONChOSCOPE

by ExPEriENCED aNESThESiOlOgiSTS

�� Kemal T� Saracoglu, Murat Acarel, Tumay Umuroglu, Fevzi Y� Gogus 503

cAsE rEports

ulTraSOuND-guiDED rEgiONal aNESThESia iN a PEDiaTriC PaTiENT WiTh aCuTE iNTErmiTTENT POrPhyria: liTEraTurE rEviEW aND CaSE rEPOrT

��Yetunde Olutunmbi, Harshad G� Gurnaney, Jorge A� Galvez, Allan F� Simpao

511

444

aNESThETiC CONSiDEraTiONS aND maNagEmENT OF a PaTiENT WiTh uNSuSPECTED CarCiNOiD CriSiS DuriNg hEPaTiC TumOr rESECTiON

��Clark K� Choi 515uNuSually DiFFiCulT iNTraESOPhagEal bOugiE iNSErTiON iN aN iNTubaTED PEDiaTriC PaTiENT

�� Xiaoyu Zhang, Xuan Zhao 519

lEttEr to tHE Editor

SuCCESSFul iNTubaTiON uSiNg mCgraTh® maC iN a PaTiENT WiTh TrEaChEr COlliNS SyNDrOmE

��Takatoshi Tsujimoto, Satoshi Tanaka, Yuki Yoshiyama, Yuki Sugiyama, Mikito Kawamata

523

corrEspondEncE

aNESThESia CarE PrOviDErS’ baSED iNTErDiSCiPliNary PEri-OPEraTivE CrOSS-OvEr POST-markET-SaFETy-SurvEillaNCE: iS iT FuTuriSTiC PaTiENT SaFETy iDEa? ruNNiNg TiTlE: POST-hirE PmSS FOr iNTErvENTiONiSTS

�� Deepak Gupta 527

M.E.J. ANESTH 22 (5), 2014

Clinical or laboratory investigations:The following structured format is required:

1. Cover Letter 7. Discussion

2. Title page 8. Acknowledgements

3. Abstract 9. References

4. Introduction 10. Tables

5. Methods 11. Figures

6. Results

1. Cover LetterManuscripts must be accompanied by a cover letter, signed by all authors and stating that:

- All authors have contributed intellectually to the manuscript and the manuscript has been read and approved by all the authors.

- The manuscript has not been published, simultaneously submitted or accepted for publication elsewhere.

2. Title PageStarts at page 1 and includes:

- A concise and informative title (preferably less than 15 words). Authors should include all information in the title that will make electronic retrieval of the article both sensitive and specific.

- Authors listing: first name, middle initial and last name with a superscript denoting the academic degrees as footprints.

- The name of the department(s) and institutions(s) to which the work should be attributed.

- The name, address, telephone, fax numbers and e-mail address of the corresponding author.

- Disclose sources of financial support (grants, equipment, drug etc…).

- Conflict of interest: disclosure of any financial relationships between authors and commercial interests with a vested interest in the outcome of the study.

- A running head, around 40 characters.- Word count of the text only (excluding abstract,

acknowledgements, figure legends and references).

3. AbstractAbstract should follow the title page. It should be

structured with background, methods, results and conclusion.

The Middle East of Anesthesiology publishes original work in the fields of anesthesiology, intensive care, pain, and emergency medicine. This includes clinical or laboratory investigations, review articles, case reports and letters to the Editor.

Submission of manuscripts:The Middle East Journal of Anesthesiology accepts

electronic submission of manuscripts as an e-mail attachment only.

Manuscripts must be submitted via email attachment to:

Editor-In-Chief,

Department of Anesthesiology,

American University of Beirut Medical Center

Beirut, Lebanon

E-mail: [email protected]

Human SubjectsManuscripts describing investigations performed in

humans must state that the study was approved by the appropriate Institutional Review Board and written informed consent was obtained from all patients or parents of minors.

Language:Articles are published in English.

Manuscript PreparationManuscript format required:

Double-spaced lines

Wide margins (1.5 inches or 3.8 cm)

Page numbers start on title page

Word count should reflect text only (excluding abstract, references, figures and tables).

Editorial 1500

Abstract 250 (General articles)100 (Case Reports)

Review article 4000

Original article 3000

Case Reports 800

Letter to Editor 500

GUIDELINES FOR AUTHORS

8. AcknowledgementsThey should be brief. Individuals named must be given

the opportunity to read the paper and approve their inclusion in the acknowledgments.

9. References- References should be indicated by Arabic numerals in

the text in the form of superscript and listed at the end of the paper in the order of their appearance. Please be accurate, giving the names of all authors and initials, the exact title, the correct abbreviation of the journal, year of publication, volume number and page numbers.

- The titles of journals should be abbreviated according to the style used in the list of Journals Indexed for MEDLINE.

Example: (1) from a journal (2) from a book.1. SHAWW: AND ROOT B: Brachial plexus anesthesia

Comparatives study of agents and techniques. Am. J. Surg.; 1951, 81:407.

2. ROBINSON JS: Modern Trends in Anaesthesia, Evans and Gray Ch. 8, Butterworth Pub. Co., London 1967.

10. TablesTables capture information concisely and display it

efficiently: They also provide information at any desired level of details and precision. Including data in tables rather than text frequently makes it possible to reduce the length of the text.

- Type or print each table with double spacing on a separate sheet of paper.

- Number tables consecutively in the order of their first citation in the text.

- Supply a brief title for each.- Place explanatory matter in footnotes, not in the

heading.- Explain all nonstandard abbreviations in footnotes.- Identify statistical measures of variations, such as

standard deviation and standard error of the mean.

11. Figures- Figures should be submitted in JPEG or TIFF format

with a minimum of 150 DPI in resolution.- Colored data if requested by author is chargeable.- If a figure has been published previously, acknowledge

the original source and submit written permission from the copyrights holder to produce the figure.

Abbreviations and symbols:- Use only standard abbreviations.- Avoid abbreviations in the title of the manuscript.- The spelled-out abbreviations followed by the

abbreviation in parenthesis should be used in first mention.

It should state, the specific purpose of the research or hypotheses tested by the study, basic procedures, main findings and principal conclusions.

Provide separate word count for the abstract.

4. IntroductionProvide the nature of the problem and its significance.

State the specific purpose or research objectives or hypothesis tested. Provide only directly pertinent references and do not include data or conclusions from the work being reported.

5. MethodsA. Selection and description of participants:

- Describe selection of participants (including controls) clearly, including eligibility and exclusion criteria.

B. Technical information:- Identify the methods, apparatus (give the

manufacturer’s name and address in parentheses), and procedure in sufficient detail to allow others to reproduce the results. Give references to established methods. Provide references and brief descriptions for methods that have been published. Identify precisely all drugs and chemicals used, including generic names(s), dose(s) ands routes(s) of administration.

C. Statistics-describe statistical methods with enough detail to enable a knowledgeable reader with access to the original date to verify the reported results. Define statistical terms, abbreviations and most symbols. Specify the computer software used. Provide a power analysis for the study.

6. ResultsPresent your results in logical sequence in the text, tables

and illustrations, giving the main or most important findings first. Do not repeat all the data in the tables or illustrations in the text: emphasize or summarize only the most important observations. Extra or supplementary materials and technical details can be placed in an appendix.

7. DiscussionEmphasize the new and important findings of the study

and the conclusions that may be drawn.

Do not repeat in details data or other information given in the Introduction or the Results sections. For experimental studies, it is useful to begin the discussion by summarizing briefly the main findings, then explore possible mechanisms or explanations for these findings, compare and contrast the results with other relevant studies. State the limitations of the study, and explore the implications of the findings for future research and for clinical practice. Link the conclusions with the goals of the study, but avoid unjustified statements and conclusions not adequately supported by the data.

445 M.E.J. ANESTH 22 (5), 2014

EDITORIAL

PREOXYGENATION-ROuTINE PREOXYGENATION duRING INducTION ANd REcOvERY fROm ANEsThEsIA

Is REcOmmENdEd As A mINImAl sAfETY PREcAuTION

With the introduction of the rapid sequence induction of anesthesia and tracheal intubation technique in the 1950s in patients who are at risk for aspiration of gastric contents, preoxygenation became an essential component of the technique1. In 1955, hamilton and Eastwood showed that “denitrogenation” was 95% complete within 2 to 3 minutes in subjects breathing normally from a circle anesthesia system with 5 l/min oxygen2.

Baraka et al 1999 reported that rapid and effective preoxygenation can be achieved by using eight deep breaths within 60 seconds, and an oxygen flow of 10 L/min. This technique can produce PaO2 values comparable to that achieved by the “traditional” preoxygenation technique. Also, it delays the onset of subsequent apnea-induced hemoglobin desaturation more significantly than following the other techniques of preoxygenation3. The mean times from the onset of apnea until hemoglobin desaturation from 100% to 99% was significantly longer following eight-deep breaths preoxygenation compared with the traditional 3 min of tidal volume breathing. The slower desaturation during apnea following the eight-deep breaths preoxygenation technique despite the comparable initial PaO2 values was unexpected. It is possible that deep breathing for 60 sec may open collapsed airways and/or lung alveoli with a consequent increase of the oxygen store in the functional residual capacity (fRc). Rapid preoxygenation with the eight deep breaths can be used as an alternative to the traditional 3-min tidal volume breathing technique3.

In his Editorial, Benumof suggested that the report of Baraka et al1 describes a new method of preoxygenation that may be best with regard to both efficacy and efficiency4. he also suggested that maximal preoxygenation is indicated not only during rapid sequence induction of anesthesia in patient with full stomach, but also in any patient with oxygen transport limitations (who desaturate the fastest), and in any patient in whom difficulty in managing the airway is suspected. Moreover, because the development of a cannot-ventilate, cannot-intubate situation is largely unpredictable, the desirability/need to maximally preoxygenate is theoretically present for all patients4.

The original American Society of Anesthesiologists (ASA) difficult airway algorithm (1993) makes no mention of preoxygenation. In his editorial, Benumof 1999 recommended maximal preoxygenation in patients with oxygen transport limitations who desaturate the fastest, and in patients with a difficult airway4. Along this line of though, the AsA inserted 2003 a new statement in the updated difficult airway algorithm “Actively pursue opportunities to deliver supplemental oxygen throughout the period of difficult airway management”5,6. moreover, because the development of the cannot-ventilate, cannot-intubate situation is largely unpredictable, the desirability/need to maximally preoxygenate is theoretically present for all patients. however, it must be noted that the safe period of apnea following preoxygenation, is still limited.

446 BARAkA A.

The saO2 may be misleading as a guide to alveolar denitrogenation and efficient preoxygenation. A saturation of 100% measured by pulse oximetry is not a reason to stop denitrogenation, and may occur well before the lungs are adequately denitrogenated. conversely, failure of spO2 to increase substantially during denitrogenation does not necessarily indicate failure of preoxygenation. With normal lung function, the oxygen wash in and the nitrogen washout are exponential. The end tidal O2 or N2 can be used to monitor preoxygenation7.

Preoxygenation followed by oxygen insufflations during subsequent apnea via a patent airway maintains saO2 by apneic diffusion oxygenation7,8. In the apneic adult, the vO2 averages 230 ml/min, whereas the output of cO2 to the alveoli is limited to about 21 ml/min only, and the remaining cO2 production is buffered within the body tissues. Therefore, a pressure gradient is created between the upper airway and the alveoli resulting in a mass movement of O2 down the trachea into the alveoli. Because of this mass movement of O2 down the trachea, cO2 is not exhaled, and hence the alveolar cO2 concentration shows an initial rise of about 8-16 mmHg during the first minute and a subsequent fairly linear rise of about 3 mmhg/min. The increase in cO2 during apneic mass-movement oxygenation and not hypoxemia becomes the limiting factor.

during apneic mass movement oxygenation via an open airway the increase in time to hb desaturation

achieved by increasing the fiO2 from 0.9 to 1.0 is greater than that caused by increasing the fiO2 from 0.21 to 0.99. The technique of preoxygenation, followed by mass-movement oxygenation during the subsequent apnea is highly recommended in patients who may rapidly desaturate.

In conclusion, “Routine” preoxygenation before rapid-sequence induction of general anesthesia in patients with full stomach, is also recommended in patients with suspected difficult airway, as well as in patients with increased oxygen consumption associated with decreased functional residual capacity of the lungs such as children, the pregnant and the morbidly obese patients, as well as in all critically ill patients. The technique is also indicated not only during induction of anesthesia, but also during reversal of neuromuscular block and emergence from anesthesia7. moreover, because the development of hypoxemia may be unpredictable, ‘routine” preoxygenation during both induction of and recovery from anesthesia is recommended in all patients as a minimal safety precaution, similar to “fasten your seat belt” during takeoff and landing of planes.

Anis Baraka, md, fRcA (hon)

Emeritus Professor of Anesthesiology

American university of Beirut

Beirut - lebanon

M.E.J. ANESTH 22 (5), 2014

447PREOXYGENATION-ROuTINE PREOXYGENATION duRING INducTION ANd REcOvERY fROm ANEsThEsIA Is REcOmmENdEd As A mINImAl sAfETY PREcAuTION

References

1. Morton HJV, Wylie WD: Anaesthetic deaths due to regurgitation and vomiting. Anaesthesia; 1951, 6:190.

2. HaMilton WK, eastWooD DW: A study of denitrogenation with some inhalation anesthesia systems. Anesthesiology; 1955, 61:861-867.

3. anis s. BaraKa, saMar K. taHa, Marie t. aouaD, MoHaMaD F. el-KHatiB, naDine i. KaWKaBani: Preoxygenation. comparison of maximal breathing and Tidal volume Breathing Techniques. Anesthesiology; 1999, 91:612-616.

4. JonatHan BenuMoF: Editorial. Preoxygenation - Best method for Efficacy and Efficiency? Anesthesiology; 1999, 91:603-609.

5. American society of Anesthesiologists Task force on management of the difficult airway. Practice guidelines for management of the difficult airway. Anesthesiology; 1993, 78:597-602.

6. ansgar M, BraMBrinK, Carin a. HagBerg: The ASA Difficult

Airway Algorithm. Analysis and presentation of a new algorithm - Benumof and hagberg’s Airway management Third edition, chapter 10, pp. 222-239, 2013.

7. anis s. BaraKa, M. raMez saleM: Preoxygenation: Benumof and hagberg’s Airway management. Third edition, chapter 13, pp. 280-297, 2013.

8. HolMDaHl MH: Pulmonary uptake of oxygen, acid-base metabolism, and circulation during prolonged apnea. Acta Chir Scan; 1956, 212 (supp): 1-128.

9. FraMery DD, roe g: A model to describe the rate of oxyhemoglobin desaturate during apnea. Br J Anesth; 1996, 76:284-291.

10. BaraKa as, taHa sK, siDDiK sM, et al: supplementation of preoxygenation in morbidly obese patients using nasopharyngeal oxygen insufflations. Anaesthesia; 2007, 62:769-773.

449 M.E.J. ANESTH 22 (5), 2014

REVIEW ARTICLE

Fentanyl - Induced cough - PathoPhysIology and PreventIon

Mabelle C. Tannous el baissari*, saMar K. Taha**, and sahar M. siddiK-sayyid***

Abstract

Many reports have demonstrated that intravenous administration of a bolus of fentanyl at induction of anesthesia can cause coughing with varying degrees. this cough can be benign, but sometimes it causes undesirable side effects including an increase in intraabdominal, intracranial or intraocular pressure. Many studies demonstrated that the incidence and severity of fentanyl-induced cough could be related to age, ethnicity, history of smoking, as well as to the rate, route, dose and concentration of fentanyl administered. this cough was described by several mechanisms including an inhibition of central sympathetic system leading to vagal predominance, reflex bronchonstriction after the stimulation of tracheobronchial tree receptors, or histamine release. The efficacy of several measures to avoid fentanyl-induced cough have been demonstrated, and several anesthetics adjuncts can be given prior to fentanyl administration aiming at decreasing this unwanted side effect.

Introduction

Fentanyl and its derivatives sufentanil, alfentanil, and recently remifentanil are the most frequently used opioids in clinical anesthesia. these synthetic potent opioids derived from phenylpiperidine are primarily administered for their analgesic effect especially prior to induction of anesthesia. they are also used to produce sedation for many procedures including endoscopy, cardiac catheterization, lumbar puncture and bone marrow aspirate/biopsy in pediatric oncology patients, as well as in the management of chronic pain including cancer pain, and others.

Fentanyl, first synthesized in 1960, is a µ-opioid receptor agonist and has clinical potency ratio 50 to 100 times that of morphine. It is characterized by its rapid onset, short duration of action, profound dose-dependent analgesia, and cardiovascular stability mainly during laryngoscopy and endotracheal intubation, and is less likely to cause histamine release1,2.

as any other opioid, fentanyl has several side effects including nausea, constipation, dry mouth, somnolence, asthenia, hypoventilation, and apnea. another important side effect is the fentanyl-induced cough. Many reports have demonstrated that a bolus of fentanyl at induction of

* Md, chief resident.** Md, associate Professor.*** Md, Frca, Professor. Affiliation: Department of Anesthesiology American University of Beirut-Medical Center, Beirut-Lebanon. Corresponding author: Sahar Siddik-Sayyid, MD FRCA, Professor, American University of Beirut Department of

Anesthesiology P.O. Box: 11-0236 Beirut, Lebanon. Tel: 9611350000, Fax: 961 1 745249. E-mail: [email protected]

450 EL BAISSARI TAnnOUS M. C. et. al

anesthesia can cause coughing with varying degrees. cough was also described after alfentanil, sufentanil, and remifentanil bolus administration at anesthesia induction3,4. this side effect can be transient, benign and self-limiting for most patients, but at times it can be spasmodic, explosive5, and life threatening6.

Fentanyl-induced cough should be avoided in patients who have potential for an increase in intracranial pressure such as cerebral aneurysms, arterio-venous malformation, cerebral tumor, or have already increased intracranial pressure such as ruptured cerebral aneurysms, and in patients with acute glaucoma, penetrating eye injuries, or dissecting aortic aneurysm. although fentanyl-induced cough is not more frequent in chronic obstructive pulmonary disease or asthmatic patients7, it is wise to avoid cough in this group of patients who have hypersensitive airway.

Fentanyl-induced cough pathophysiology

Cough is a well-integrated reflex resulting from mechanical and chemical stimulations of sensory receptors. the most likely receptors are the rapidly adapting pulmonary stretch receptors (rars) with small diameter A delta myelinated fibers (localized mainly at the larynx) and the pulmonary and bronchial C-fiber receptors with nonmyelinated afferents. These fibers constitute the afferent limb which interacts with brainstem cough center, while the efferent limb consists of motor nerves that supply the muscles of coughing8. a new concept of the central regulatory system for cough reflex has been suggested. Cough-gating neurons, located in the ventrolateral nucleus tractus solitarius, play a crucial role in the generation of cough reflex. In fact, the second order relay neurons in the nucleus tractus solitarius receive peripheral tussigenic inputs. the cough-gating neurons, constituting the gating mechanism, integrate these afferents inputs and activate the central cough/respiratory pattern generator by producing triggering signals. Finally, the produced cough motor task is transmitted to the inspiratory and expiratory muscles through activation of respiratory motoneurons. the cough pattern generator in the brainstem appears to be identical to the respiratory pattern generator and

to function by reshaping of the discharge pattern of respiratory neurons9.

regarding the mechanism of cough induced by opioids, several hypotheses were implicated. the rapidly adapting receptors present on the mucosa of the proximal tracheobronchial airway can be stimulated by fentanyl causing bronchoconstriction and cough which can be suppressed by inhaled beta 2-agonists such as terbutaline10 or salbutamol11. In addition, tanaka et al. demonstrated that the topical application of citrate on C fibers of the airway induces cough in animals and humans12. since fentanyl is available as citrate salts, citrate can stimulate C fibers (known also as J-receptors) present on the smooth muscles of trachea and bronchi releasing neuropeptides such as tachykinins or bradykinins responsible for the cough. these J receptors are accessible via pulmonary circulation and are very sensitive to chemical irritants13. the differences in the incidence and severity of cough among different opioids may be attributed to the amount of citrate in opioids14.

histamine release is a possible cause for inducing cough by fentanyl, but this is not clear as fentanyl rarely causes histamine release in mast cells of the lungs. however, argwal et al study showed that sodium chromoglycate, a mast cell stabilizer, led to a decrease in the incidence of fentanyl-induced cough11.

Fentanyl has been shown to enhance vagal activity while inhibiting sympathetic nervous system leading to reflex bronchoconstriction and cough15. recently, it appears unlikely that the vagal system stimulation mediates fentanyl-induced cough as premedication by anticholinergic drugs as atropine does not decrease its incidence7,16.

Alternative hypothesis that should be verified by further studies is that the muscle rigidity produced by fentanyl can cause sudden adduction of vocal cords or supraglottic obstruction17, and a priming dose of vecuronium could decrease the incidence of fentanyl-induced cough7.

Incidence of fentanyl-induced cough

the discrepancies in the incidence of fentanyl-induced cough may be related to age, ethnicity,

M.E.J. ANESTH 22 (5), 2014

451Fentanyl - Induced cough - PathoPhysIology and PreventIon

smoking, as well as to different doses, rates and routes of fentanyl administration.

1. Age: The incidence of fentanyl-induced cough is high in infants and children, even in small doses (1 µg/kg)18-20. This can be explained by an increase in irritant cough receptors17. however, lin et al showed that age has no effect on the incidence of cough21.

2. Ethnicity: Fentanyl-induced cough may be more evident in asian population than european one16,22. schapermeier and hopf demonstrated that the incidence of cough following intravenous (Iv) fentanyl 1.5 µg/kg ranges between 3% and 6% in european patients22 whereas Phua et al showed that this incidence is 28% using the same fentanyl dose in asian patients16.

3. Smoking: There is a controversy regarding the implication of smoking in increasing the incidence of fentanyl-induced cough. Baley reported that fentanyl-induced cough was noticeable in smokers23. however, dimitriou et al. demonstrated that the incidence of cough in the non-smoker and smoker group (more than 10 cigarettes per day) was similar after administration of 2-3 µg/kg of fentanyl during anesthesia induction24. lin et al. demonstrated that light smoking may be a protective factor against fentanyl-induced cough. they showed that smokers who smoked fewer than 10 cigarettes per day have less fentanyl-induced cough than nonsmokers after administration of 2 µg /kg of fentanyl, but there was no difference between heavy smokers (more than 10 cigarettes per day) and non-smokers21. this can be explained by the inhibitory effects of nicotine on C fibers in current light smokers which are abolished in heavy smoker patients25.

4. Doses of injection: As shown in several previous studies, the incidence of fentanyl-induced cough increases proportionally with the doses. With a speed of injection of fentanyl less than 2 seconds at induction time, the cough incidence increased from 6.6% to 61% when fentanyl dose increased from 2 µg/kg to 4 µg/kg (table 1). All these doses were administered peripherally.

5. Speed of injection: Schapermeier and Hopf showed in their study that injection of 1.5 µg /kg of fentanyl over 2, 5 or 10 seconds leads to similar incidence of cough ranging from 3% to 6%, concluding that

the speed of injection does not affect the incidence of cough22. however, lin et al showed that a longer injection time can reduce the incidence of fentanyl-induced cough. Fentanyl injection (2 µg/kg) induced cough in 18% of patients with an injection time less than 2 seconds; increasing injection time to 30 seconds yielded a drop in the incidence of evoked cough to 1.3%21. This can be explained by less chance of fentanyl to reach the threshold of plasma concentration as the mean time of fentanyl to reach the peak plasma concentration is 15 seconds25. In another study, lin et al study showed that administration of 2.5 µg /kg of fentanyl over two seconds can reach 65 %17.

6. Route of administration: The different routes of fentanyl administration have been evaluated in different studies. high incidence of fentanyl-induced cough has been observed when fentanyl was given at a high dose and via a central line. Bohrer et al. showed that Iv administration of large dose of fentanyl 7 µg /kg via a central line causes cough with an incidence reaching 45%. vs 2.7% when the same dose was given peripherally, which can explain the direct fentanyl stimulation of the pulmonary chemoreflexes13.

Onset of fentanyl-induced cough

In addition to the pharmacokinetic property of fentanyl, the dose, speed of injection, and route of administration contribute to the onset time of cough. chen et al study showed that the rate of fentanyl injection through the same peripheral venous access at the same dose may affect both the incidence and onset time of cough. at the same dose and injection rate of fentanyl, forearm venous access of injection resulted in earlier onset of cough than lower limb venous access with a similar incidence26. In two other studies, the onset of cough was 9 seconds when 7 µg/kg fentanyl bolus was administered via a central line13 and 42±8 seconds when 5 µg /kg was injected over 5 seconds peripherally10.

Pharmacological intervention to reduce fentanyl-induced cough


Table 1 Incidence of cough after fentanyl administration through peripheral line and summary of effective methods to prevent it. The articles

are listed as per increasing fentanyl doses.references number of cases

per groupFentanyl dose (μg/

kg)

time of injection (seconds)

Incidence of cough after

fentanyl (control) (%)

Medications to prevent cough Incidence of cough after

medication (%)

Lida et al, 200953. 106 135

na 6.622.544.3

no intervention

Phua et al. 199116. 50 1.5 na 28 Atropine (0.01mg/kg)Morphine (0.2mg/kg)Midazolam (7.5mg)

30640

chung-chang et al. 200735.

180 1.5 5 21.6 Ketamine (0.15mg/kg) 7.2

Horng et al. 200736. 150 2 <2 38.7 Clonidine (2 μg /kg) 17.3Lin et al. 200521. 150 ~2 <2

1530

188

1.3

no intervention

Lin et al. 200744. 108 (fentanyl group)/80

(Dexamethasone group)

~2 2 21.3 Dexamethasone 10mg) 6.3

Argwal et al. 200311. 50 2 5 28 one puff salbutamolOne puff Beclomethasoneone puff sodium chromoglycate

604

Qing et al. 201046. 93 2 2 22.6 Pentazocine (0.5mg/kg) 4.3Hung et al. 201051. 200 ~2 na 18.5 Preemptive fentanyl dose 25µg 7.5Tang et al. 201049. 30 2.5 1.5±0.3 80

(Intralipid 0.15ml/kg)

Propofol (1mg/kg)Propofol (1.5mg/kg)Propofol (2mg/kg)

406.73.3

Lin et al. 200417. 31 2.5 2 65 Lidocaine (2mg/kg)Ephedrine (5mg):Propofol (0.6mg/kg):

142137

Yu et al. 201240. 110 3 na 40.9 Midazolam (0.6mg/kg)Dexmedetomidine (0.6 μg /kg)Midazolam(0.6mg/kg)+dex(0.6 μg /kg)

63.622.7

0

Pandey et al. 200431. 251 3 na 34.22 Lidocaine (1.5mg/kg): 13.1Pandey et al. 200532. 80 3 na 35 Lidocaine (0.5mg/kg):

Lidocaine (1mg/kg):Lidocaine (1.5mg/kg):

13.7515

13.75Yu et al. 200719. 50 3 3-5 32 dilution of fentanyl from

50µg/ml to 25µg/ml50µg/ml to 10µg/ml50µg/ml to 10µg/ml+ prolonged time to injection

1612

2Liang et al. 201237. 100 4 <2 61 Dexmedetomidine (0.5 μg /kg):

Dexmedetomidine (1mcg/kg):4018

Lui et al. 199610. 30 5 na 43 Terbutaline (5mg): 3Sun et al. 201147. 60 5 <2 70 Dezocine (|0.1mg/kg) 0Bohrer et al. 199013. 37 7 1 2.7 no intervention

na (not available)

M.E.J. ANESTH 22 (5), 2014


several pharmacological interventions were done to decrease this side-effect with varying success.

1. Lidocaine: IV lidocaine has been demonstrated to decrease airway reflexes including cough reflex during tracheal intubation27, extubation28, and bronchography29. as a proposed mechanism, lidocaine can act centrally by depression of brainstem functions or peripherally by blocking tracheal and hypo-pharyngeal cough receptors30. Pandey and co-authors demonstrated that 1.5 mg/kg of lidocaine administered one minute before 3 µg/kg of fentanyl can decrease significantly the incidence of cough31. In a dose-response study, he demonstrated that administration of a low dose of lidocaine (0.5 mg/kg Iv) over 5 seconds, one minute prior to an induction bolus of fentanyl 3 µg /kg, is effective in decreasing fentanyl-induced cough and that increasing lidocaine dose up to 1.5 mg/kg does not reduce the incidence and severity of fentanyl-induced cough32. lin et al showed the administration of lidocaine 2 mg/kg one minute before fentanyl 2.5 µg/kg over 2 seconds at induction can suppress cough reflex17. a recent meta-analysis showed that lidocaine reduces the incidence and severity of fentanyl-induced cough, and that the lowest effective dose of lidocaine for preventing the prevalence of cough was 0.5 mg/kg. no severe adverse effects were reported33.

2. Beta 2-adrenergic receptors: As previously mentioned, one of the proposed mechanisms for fentanyl-induced cough is fentanyl-triggered bronchoconstriction. ephedrine, a sympathomimetic drug that acts as a bronchodilator, can be safely administered intravenously at a small dose (5 mg) in healthy patients, but it is relatively contraindicated in patients with severe hypertension or coronary artery disease17. Other beta-2 adrenergic receptor agonists such as nebulized terbutaline10 and salbutamol11 were effective in decreasing the incidence of fentanyl-induced cough.

3. Ketamine: It has been also demonstrated that excitatory amino acids and n-methyl - D-aspartate (nMDA) receptor agonists present in the larynx, lungs and airways are capable of stimulating cough reflex34; ketamine, an nMDA receptor antagonist, characterized by its potent analgesic and bronchodilator effect has been used as premedication

with a dose of 0.15 mg/kg and was effective in decreasing the incidence of fentanyl-induced cough and delaying its onset35.

4. Alpha 2-adrenoreceptor agonist: Clonindine, an alpha 2-adrenoreceptor agonist known by its analgesic, anxiolytic, and sedative effects, is widely used as premedication before surgery. horng and co-authors demonstrated that premedication with 2 µg /kg of clonidine followed 2 minutes later by administration of 2 µg/kg of fentanyl within 2 seconds decreases the incidence of cough from 38.7% to 17.3%36. recently, the usage of dexmedetomidine, a highly selective alpha 2-adrenoreceptor agonist at doses of 0.5 µg /kg and 1 µg /kg has been effective in reducing cough when 4 µg/kg of fentanyl was injected in less than 2 seconds without causing major cardiovascular instability. however, the severity and onset of time of cough were not affected37. the mechanism by which these alpha 2-agonists decrease cough is unclear. It could be attributed to the sedative and broncho-relaxant properties as for ketamine, midazolam and propofol38. hung speculated that clonidine suppresses opioid-induced cough by reducing opioid-induced muscle rigidity that causes the sudden adduction of the vocal cords or supraglottic obstruction39.

yu et al. showed that the premedication with dexmedetomidine 0.6 µg/kg and midazolam 0.06 mg/kg, 2 minutes before injecting fentanyl 3 µg/kg within 2 seconds, suppresses completely fentanyl-induced cough, while an incidence of 22.7% was observed after the administration of 0.6 µg/kg of dexmedetomidine alone40.

5. Dexamethasone: Tachykinin release stimulates the rapidly activating receptors either directly by contracting smooth muscles or indirectly by inducing histamine release from airway masts cells. It has been reported that dexamethasone can stabilize mast cells41 and reduce tachykinin-induced bronchoconstriction in guina pigs, but this needs more investigation in humans42. In addition, it has been reported that dexamethasone stimulates neutral endopeptidase which reverses the enhanced airway reactivity of airway epithelial cells43. lin et al study showed that 10 mg of dexamethasone 5 min prior to injection of fentanyl 100 µg/kg in 40-69 kg patient or 150 µg/kg in a 70-90 kg patient


reduces the incidence of fentanyl-induced cough44.

Yu and coauthors demonstrated also that 10 mg of dexamethasone can decrease cough from 26.5% to 6.5% when remifentanil was used and reached a target concentration of 5 ng/ml45.

6. Agonist-antagonist opioid: Recently, pentazocine, an agonist of kappa and sigma receptors and a weak antagonist of µ-receptors, has been shown to be effective in decreasing cough. Qing et al. showed that 0.5 mg/kg of pentazocine given 5 min prior to administration of 2 µg/kg of fentanyl over 2 seconds decreases the incidence of cough from 22.6% to 4.3%46. also, dezocine, a full antagonist-kappa receptor and partial agonist-mu receptor, was used to decrease cough when administered at a dose of 0.1 mg/kg 10 minutes prior to injection of 5 µg /kg of fentanyl; however, more studies are needed to clarify the effects and mechanisms of action of dezocine in suppressing fentanyl-induced cough47.

7. Propofol: This drug is known to have a bronchodilator effect38,48, and priming doses ranging from 1 mg/kg to 2 mg/kg administered before anesthesia induction were effective in suppressing the cough49. however, Lin et al observed that premedication with 0.6 mg/kg of propofol could not inhibit fentanyl-induced cough17.

8. Priming doses of fentanyl: It has been shown that a priming fentanyl dose of 0.5 µg/kg50 or preemptive use of 25 µg fentanyl administered 1 minute prior to 125 µg or 150 µg of fentanyl51 could suppress

effectively the cough. the preemptive dose of fentanyl releases neurotransmitters that do not reach the threshold to cause cough. however, after a larger dose of fentanyl, there will be an exhaustion of these neurotransmitters resulting in a lower incidence of cough50.

9. Dilution of fentanyl: Yu et al found that fentanyl diluted from 50 µg/ml to 25 µg/ml and 10 µg/ml injected over 3-5 seconds reduces the incidence of cough, and that administration of 3 µg/kg of fentanyl diluted to 10 µg/ml combined with a prolonged injection time to 30 seconds eliminates completely fentanyl-induced cough19.

10. non-therapeutic modalities: Ambesh et al. reported a significantly reduced cough (32% to 4%) induced by 2.5 µg/kg of fentanyl if a huffing maneuver was done before induction of anesthesia52.

Conclusion

cough with varying degrees of severity can be caused by intravenous administration of fentanyl bolus at induction of anesthesia. although most of the time benign, it can be sometimes associated with undesirable side effects. In order to decrease its incidence and severity, the route, rate, dose, and concentration of fentanyl injection should be taken into consideration, and several adjuncts can be given prior to fentanyl administration.

M.E.J. ANESTH 22 (5), 2014


References

1. Ko sh, KiM dC, han yJ eT al: Small-dose fentanyl: optimal time of injection for blunting the circulatory reponses to tracheal intubation. Anesth Analg; 1998, 86:658-61.

2. adaChi yu, saToMoTo M, higuChi h, eT al: Fentanyl attenuates the hemodynamic response to endotracheal intubation more than the response to laryngoscopy. Anesth Analg; 2002, 95:233-7.

3. shen JC, Xu Jg, Zhou ZQ, eT al: Effect of equivalent doses of fentanyl, sufentanil or remifentanil on incidence and severity of cough in 315 patients: A randomized, double blind study. Curr Ther Res Clin E; 2008, 69:480-7.

4. Cho hb, KwaK hJ, ParK sy, eT al: Comparison of the incidence and severity of cough after alfentanil and remifentanil injection. Acta Anaesthesiol Scand; 2010, 54:717-20.

5. Tweed wa, daKin d: Explosive coughing after bolus fentanyl injection. Anesth Analg; 2001, 92:1442-3.

6. aMbesh s, singh n, srivasTava K: Fentanyl induced coughing caused life-threatening airway obstruction in a patient with arteriovenous malformation of tongue and hypopharynx. Int Janesthesiol; 2009, 20:7.

7. oshiMa T, Kasuya y, oKuMura y, eT al: Identification of independent risk factors for fentanyl-induced cough. Can J Anesth; 2006, 53(8):753-8.

8. widdiCoMbe Jg: neurophysiology of the cough reflex. Eur respire J; 1995, 8:1193-202.

9. haJi a, KiMura s, ohi y: A Model of the Central Regulatory System for Cough Reflex. Biol Pharm Bull; 2013, 36(4) 501-508.

10. lui Pw, hsing Ch, Chu yC: Terbutaline inhalation suppresses fentanyl-induced coughing. Can J Anaesth; 1996, 43:1216-9.

11. agarwal a, gauTaM s, naTh ss, eT al: Comparison of the incidence and severity of cough induced by sufentanil and fentanyl: a prospective, randomised, double-blind study. Anesthesia; 2007, 62:1230-2.

12. TanaKa M, MaruyaMa K: Mechanisms of capsaicin and citric acid induced cough reflexes in guinea pigs. Journal of Pharmacological Sciences; 2005, 99:77-82.

13. bohrer h, Fleisher F, werning P: Tussive effect of a fentanyl bolus administration through a central venous catheter. Anaesthesia; 1990, 45:18-21.

14. agarwal a, aZiM a, aMbesh s, eT al: Sabutamol, beclomethasone or sodium chromoglycate suppress coughing induced by iv fentanyl. Can J Anesth; 2003, 50:297-300.

15. reiTan Ja, sTengerT Kb, wyMore Ml, eT al: Central vagal control of fentanyl-induced bradycardia during halothane anesthesia. Anesth Analg; 1978, 57:31-6.

16. Phua wT, Teh bT, Jong w, eT al: Tussive effect of a fentanyl bolus. Can J Anaesth; 1991, 38:330-4.

17. lin Cs, sun wZ, Chan wh, eT al: Intravenous lidocaine and ephedrine, but not propofol, suppress fentanyl-induced cough. Can J Anaesth; 2004, 51:654-9.

18. han Ji, lee gy, lee Ch, eT al: Tussive effect of intravenous fentanyl administration and antitussive effect of lidocaine. Korean J Anesthesiol; 1996, 31:462-5.

19. yu h, yang Xy, Zhang X, eT al: The effect of dilution and prolonged injection time on fentanyl induced coughing. Anaesthesia; 2007, 62:919-22.

20. Jong ih, heeseung l, Chi hK, eT al: The frequency of fentanyl induced cough in children and its effect on tracheal intubation. J

Clin Anesth; 2010 Feb, 22(1):3-6.21. lin Ja, yeh CC, lee Ms, eT al: Prolonged injection time and light

smoking decrease the incidence of fentanyl-induced cough. Anesth Analg; 2005, 101:670-4.

22. sChäPerMeier u, hoPF hb: Fentanyl-induced cough does not depend on injection speed: a randomized study. Acta Anaesthesiol Scand; 2008, 52:1071-5.

23. bailey P: Possible Mechanism(s) of Opioid-induced Coughing. Anesthesiology; 1999, 90:335.

24. diMiTriou v, sPyrou a, ioaKiMidou a, eT al: The influence of premedication and smoking. Middle East J Anesthesiol; 2006 Jun, 18(5):943-6.

25. MillQvisT e, bende M: Capsaicin cough sensitivity is decreased in smokers. Respir Med; 2001, 95:19-21.

26. Chen yM, Chen wT, liang sw, eT al: [Intravenous injection rate and site of fentanyl affect the incidence and onset time of fentanyl-induced cough]. In chinese with english abstract. Journal of Southern Medical University; 2009 Feb, 29(2):339-40.

27. yuKioKa h, yoshiMoTo n, nishiMura K, eT al: Intravenous lidocaine as a suppressant of coughing during tracheal intubation in elderly patients. Anesth Analg; 1993, 77:309-12.

28. baraKa a: Intravenous lidocaine controls extubation laryngospasm in children. Anesth Analg; 1978, 57:506-7.

29. sMiTh Fr, Kundahl PC: Intravenously administered lidocaine as cough depressant during general anesthesia for bronchography. Chest; 1973, 63:427-9.

30. PoulTon TJ, JaMes FM: Cough suppression by lidocaine. Anesthesiology; 1979, 50: 470-2.

31. Pandey C, raZa M, ranJan r, eT al: Intravenous lidocaine suppresses fentanylinduced coughing: a double-blind, prospective, randomized placebo-controlled study. Anesth Analg; 2004, 99:1696-8.

32. Pandey CK, raZa M, ranJan r, eT al: Intravenous lidocaine 0.5 mg kg-1 effectively suppresses fentanylinduced cough. Can J Anaesth; 2005, 52:172-5.

33. sun l, guo r, sun l: The impact of prophylactic intravenous lidocaine on opioid-induced cough: a meta-analysis of randomized controlled trials. J Anesth; 2013 Oct 31, DOI 10.1007/s00540-013-1732-3.

34. KaMei J, Tanihara h, igarashi h, eT al: Effects of n-methyl-daspartate antagonists on the cough. Eur J Pharmacol; 1989, 168:153-8.

35. yeh CC, wu CT, huh bK, eT al: Premedication with intravenous low-dose ketamine suppresses fentanyl-induced cough. J Clin Anesth; 2007, 19:53-6.

36. horng hC, wong Cs, hsiao Kn, eT al: Pre-medication with intravenous clonidine suppresses fentanyl-induced cough. Acta Anaesthesiol Scand; 2007, 51:862-5.

37. liang h, Jun-Mei X, ru-Ping d: Dexmedetomidine reduces the incidence of fentanyl-induced cough: A double-blind, randomized, and placebo controlled study. Upsala Journal of Medical Sciences; 2012, 117:18-21.

38. Cheng ey, MaZZeo aJ, bosnJaK ZJ, eT al: Direct relaxant effects of intravenous anesthetics on airway smooth muscle. Anesth Analg; 1996, 83:162-168.

39. hung KC: The possible mechanism of clonidine to suppress fentanyl-induced coughing. Acta Anaesthesiol Scand; 2009, 53:1227-8.


40. yu J, lu y, dong C, eT al: Premedication with intravenous dexmedetomidine-midazolam suppresses fentanyl induced cough. Ir J Med Sci; 2012, 181:517-20.

41. leung PC, woo Ks, Chen gg, eT al: Inhibitory effects of budesonide, desloratadine and dexamethasone on cytokine release from human mast cell line (HMC-1). Inflamm Res; 2004, 53(12):664-9.

42. Murlas Cg, lang Z, ChodiMella v: Dexamethasone reduces tachykinin but not ACh airway hyperreactivity after O3. Lung; 1993, 171:109-21.

43. lang Z, Murlas Cg: neutral endopeptidase of a human airway epithelial cell line recovers after hypochlorous acid exposure: dexamethasone accelerates this by stimulating neutral endopeptidase mrna synthesis. Am J Respir Cell Mol Biol; 1992, 7:300-6.

44. lin Ja, Chen FC, lee Ms, eT al: Intravenous dexamethasone pretreatment reduces fentanyl induced cough. J Formos Med Assoc; 2007, 106:649-55.

45. yu Ms, KiM Jy, KiM hy: Intravenous dexamethasone pretreatment reduces remifentanil induced cough. Korean J Anesthesiol; 2011, 60:403-7.

46. ai Q, hu y, wang y, eT al: Pentazocine pretreatment suppresses fentanyl-induced cough. Pharmacological reports; 2010, 62:747-50.

47. sun ZT, yang Cy, Cui Z, eT al: Effect of intravenous dezocine on fentanyl-induced cough during general anesthesia induction: a

double-blinded, prospective, randomized, controlled trial. J Anesth; 2011, 25:860-3.

48. yaMaguChi M, shibaTa o, nishioKa K, eT al: Propofol attenuates ovalbumin-induced smooth muscle contraction of the sensitized rat trachea: inhibition of serotonergic and cholinergic signaling. Anesth Analg; 2006, 103:594-600.

49. Tang Q, Qian y, Zhang Q, eT al: Effects of different priming doses of propofol on fentanyl-induced cough during anesthesia induction: a preliminary randomized controlled study. Ups J Med Sci; 2010, 115:121-4.

50. gu C, Zhou M, wu h, eT al: Effects of different priming doses of fentanyl on fentanyl-induced cough: a double blind, randomized, controlled study. Pharmacological Reports; 2012, 64:321-5.

51. hung KC, Chen Cw, lin vC, eT al: The effect of pre-emptive use of minimal dose fentanyl on fentanyl-induced coughing. Anaesthesia; 2010 Jan, 65(1):4-7.

52. aMbesh sP, singh n, guPTa d, eT al: A huffing manoeuvre, immediately before induction of anaesthesia, prevents fentanyl-induced coughing: a prospective, randomized, and controlled study. Br J Anaesth; 2010, 104:40-3.

53. iida K, handa M, FuKuda K, eT al: [Incidence and onset time of fentanyl-induced cough depends on the dose of Iv fentanyl]. In Japanese with english abstract. Masui; 2009 Aug, 58(8):962-5.

457 M.E.J. ANESTH 22 (5), 2014

scientific articles

Cerebral “Hyperoxygenation” witH inHalational induCtion of anestHesia in CHildren: a retrospeCtive Comparison between vasoparalytiC sevoflurane vs.

vasoneutral fentanyl

Deepak Gupta*, Rami Bzeih** anD maRia maRkakis zestos*

abstract

Background: the higher levels of oxygen in cerebrum may contribute to neuro-apoptosis, analogous to direct tissue injury induced by toxic levels of oxygen. earlier report highlighted the possibility of cerebral “hyperoxygenation” secondary to inhalational induction of anesthesia with sevoflurane in small number of children.

Objective: the aim of this retrospective review was whether similar cerebral “hyperoxygenation” trends can be seen in larger and retrospective patients’ database.

Methods: data of patients who had undergone cardiac surgeries at Children’s Hospital during the two-year period (2010-2011) was retrieved during this retrospective review: (a) stored computer data from invos®™ Cerebral/somatic oximeter for oximetry numbers and total duration of oximetry monitoring, (b) paper chart perfusion records of the cardiac surgeries for age and sex of the patient, urgency of the surgery, type of induction (inhalational or intravenous), and total duration of cardiopulmonary bypass, (c) general medical records for inpatient setting vs. outpatient setting of the patient, and (d) anesthesia medical records for name of the medications used during induction of anesthesia to segregate the patients who had fentanyl as a lone induction agent and sevoflurane as a lone induction agent, for final statistical calculations and analysis. For the two-year period (2010-2011), data of 358 patients who had cardiac surgeries at Children’s Hospital were reviewed. However, after deletions of various patients’ data due to various reasons, only 69 patients (0-4 years of age) who had sevoflurane induction were analyzed for final statistical comparisons to 14 patients (0-4 years of age) who had fentanyl induction.

results: Cerebral and renal “hyperoxygenation” occurred during the first 127 minutes with sevoflurane as compared to fentanyl though the percentage changes from pre-induction values in oximetry during this time did not reach level of significance. However, only cerebral “hyperoxygenation” persisted in the last 127 minutes when patients had been induced with sevoflurane as compared to fentanyl.

conclusion: Cerebral “hyperoxygenation” occurs with inhalational induction of anesthesia with vasoparalytic sevoflurane in children 0 to 4 years of age when compared to anesthesia

* md.** graduate student. Affiliation: Department of Anesthesiology, Wayne State University, Detroit, Michigan, United States. corresponding author: maria markakis Zestos, md. Chief of anesthesiology, Children’s Hospital of michigan, associate professor, wayne state university, 3901 beaubien st, suite 3b-17, detroit michigan 48201, United States. Office: 1-313-745-5535. Tel: 1-313-745-5448. E-mail: [email protected]

458 gupta d. et. al

induction with vasoneutral fentanyl.

introduction

the higher levels of oxygen in cerebrum may contribute to neuro-apoptosis, analogous to direct tissue injury induced by toxic levels of oxygen. in an earlier case series discussion1, we presented the possibility of cerebral “hyperoxygenation” secondary to inhalational induction of anesthesia with sevoflurane. oxygen’s potential to possibly cause neuro-apoptosis needs further investigations to define the exact toxic levels that could harm anesthetized brains of different age groups. However, the case series discussion prompted us to investigate whether similar cerebral “hyperoxygenation” trends can be seen in larger number of patients. such trends, if present, would warrant further randomized controlled prospective trials to comprehensively validate the observations of our case series discussion1.

the current retrospective review was focused on the 0-4 years age group because this particular age group reflects a vulnerable stage in human brain development with possibly heightened sensitivity to deleterious effects of anesthesia and related peri-anesthesia factors. moreover, this age group is also the focus of investigation by smarttots (strategies for mitigating anesthesia-related neurotoxicity in tots) for validating patient safety when anesthesia is being delivered to young patients in 0-4 years age group2. as propofol is very rarely used for intravenous induction of anesthesia in small children (0-4 years of age) presenting for cardiac surgeries, the objective of this retrospective review was to compare the tissue oximetry data for the patients who received inhalational induction of anesthesia with sevoflurane for their cardiac surgeries versus the patients who had intravenous induction of anesthesia with fentanyl.

Methods

after institutional review board approval, the patients who had undergone cardiac surgeries at Children’s Hospital during the two-year period (2010-2011) were included in this retrospective review. as cerebral tissue oxygen monitoring as well as somatic

(renal) tissue oxygen monitoring with invos®™ Cerebral/somatic oximeter (®somanetics Corporation, Troy, Michigan, United States; ™Covidien, Mansfield, massachusetts, united states) are routinely applied for cardiac surgeries at our Children’s Hospital. the following patient care data was retrieved during this review for final analysis and comparison: (a) stored computer data from invos®™ Cerebral/somatic oximeter for oximetry numbers and total duration of oximetry monitoring, (b) paper chart perfusion records of the cardiac surgeries for age and sex of the patient, urgency of the surgery, type of induction (inhalational or intravenous), and total duration of cardiopulmonary bypass, (c) general medical records for inpatient setting vs. outpatient setting of the patient, and (d) anesthesia medical records for the medications used during induction of anesthesia to segregate the patients who had fentanyl as a lone induction agent and sevoflurane as a lone induction agent.

although the initial plan for data collection was inclusive of five-year period (2007-2011), major paucity of computerized oximetry data in years prior to year 2010 and inhomogeneous availability of comprehensive peri-operative characteristics of patients led to our decision to perform the final statistical calculations and analysis for a two-year period (2010-2011). the positive side of this decision was that despite being a small data (n=83 patients over two-year period), the post-hoc power analysis of the compared data was adequate.

For final statistical comparisons, the patients were divided into two groups: the group who received sevoflurane as a lone induction agent and the group who received fentanyl as a lone induction agent. each approximate-30-second-interval oximetry numbers were tabulated for anova-analysis of repeated Measures for approximately first 127 minutes (first time zone) of the oximetry monitoring (anesthesia duration) and approximately last 127 minutes (second time zone) of the oximetry monitoring. To avoid anova-analysis of repeated measures deleting individual patient’s whole oximetry data wherein that patient had few time-points with missing oximetry numbers, these tabulations were re-formatted to delete all those interspersed time-point data columns wherein any single patient had a missing data-point of oximetry

M.E.J. ANESTH 22 (5), 2014

459Cerebral “Hyperoxygenation” witH inHalational induCtion of anestHesia in CHildren: a retrospeCtive Comparison between vasoparalytiC sevoflurane vs. vasoneutral fentanyl

number at that particular time-point. therefore, an acquisition rate was defined as the ratio of time-point data columns (repeated measures) finally analyzed vs. the total time-point data columns available for that particular time zone (254 time-points of approximate-30-second-interval). other statistical tests used were: anova single factor for comparing means of continuous data, Chi-square test and two tailed fisher exact test for comparing proportions and regression analysis for correlating data. a p-value of <0.05 was considered as significant.

results

for the two-year period (2010-2011), data of 358 patients who had cardiac surgeries at Children’s Hospital were reviewed. However, after deletions of various patients’ data due to reasons specified in the Consort diagram (figure 1), only 69 patients (0-4 years of age) who had sevoflurane induction were analyzed for final statistical comparisons to 14 patients (0-4 years of age) who had fentanyl induction. fentanyl induction was significantly higher in inpatients

(p<0.0001) and in patients undergoing non-elective (urgent/emergent) cardiac surgeries (p<0.0001) (table 1). though the baseline pre-induction values of both cerebral and renal oximetry were similar between sevoflurane induction and fentanyl induction, the baseline values of cerebral oximetry and renal oximetry correlated significantly only in sevoflurane induction patients (r=0.48; p<0.0001) (table 2). the end values of cerebral oximetry (p=0.0007) and renal oximetry (P=0.0001) at skin closure were significantly different between sevoflurane induction and fentanyl induction. However the correlation between end values of cerebral oximetry and renal oximetry was significant only in sevoflurane induction patients (r=0.37; p=0.002) (table 2).

baseline cerebral oximetry (r=0.39; p=0.0002) as well as baseline renal oximetry (r=0.47; p<0.0001) proportionally increased with patients’ age (table 3). However, only the inpatients (p=0.04) and patients who had undergone non-elective cardiac surgeries (p=0.004) had significantly lower baseline renal oximetry values (table 3). durations of cardiopulmonary bypass and oximetry monitoring did not correlate with percent changes from pre-induction baseline values to end values of both cerebral and renal oximetry irrespective of the type of anesthesia induction performed (table 4).

During final comparisons of tissue oximetry (cerebral and renal) across the two time-zones (first 127 minutes and last 127 minutes), there was some overlapping of data in seven out of 83 patients because

Fig. 1 CONSORT Diagram of the Analyzed Patients’ Data after

Various Deletions/Exclusions

Table 1 Patients Pre-Morbid Characteristics (Demographics)

Characteristic Sevoflurane induction

(n=69)

fentanyl induction

(n=14)

p value

age (in years) 1.13 ±1.17 0.51 ±1.04 0.07

sex (f/m) 35 f/34 m 8 f/6 m 0.77

inpatient/same day admit setting (inpt/sda)

9 inpt/60 sda

13 inpt/1 sda

<0.0001

elective/non-elective surgery (e/ne)

64 e/5 ne 3 e/11 ne <0.0001

f: females; m: malesinpt: inpatient setting; sda: same day admit settinge: elective surgery; ne: non-elective surgery

460 gupta d. et. al

Table 2 Tissue Oximetry and Surgical Characteristics

Characteristic Sevoflurane Induction (n=69) fentanyl induction (n=14) p value

Cerebral oximetry baseline value (in %) 63.84 ±11.98 61.36 ±12.98 0.49

renal oximetry baseline value (in %) 72.29 ±15.04 65 ±16.38 0.11

Correlation of baseline Cerebral and renal oximetry

Correlation Coefficient=0.48 (p<0.0001)

Correlation Coefficient=0.46 (P=0.1)

Cardio-pulmonary bypass duration (in mins) 112.87 ±50.32 126.29 ±63.69 0.39

oximetry monitoring duration (in mins) 341.41 ±71.77 380.29 ±105.67 0.09

Cerebral oximetry end value (in %) 75.86 ±12.8 61.86 ±16.59 0.0007

renal oximetry end value (in %) 92.46 ±6.14 79.93 ±22.37 0.0001

Correlation of end values of Cerebral and renal oximetry

Correlation Coefficient=0.37 (p=0.002)

Correlation Coefficient=0.5 (p=0.07)

Table 3 Effect of Pre-Morbid Characteristics on the Pre-Induction Baseline Values of Tissue Oximetry

Correlating factor Correlation of baselineCerebral oximetry

Correlation of baselinerenal oximetry

patients’ age (n=83) Correlation Coefficient=0.39 (P=0.0002) Correlation Coefficient=0.47 (P<0.0001)patients’ sex f/m (n=83) f: 64.37 ±10.55

m: 62.4 ±13.65(p=0.46)

f: 72.37 ±15.67m: 69.65 ±15.21(p=0.43)

patients’ setting inpatient (inpt)/same day admit (sda) (n=83)

inpt: 61.32 ±13.29sda: 64.18 ±11.68(p=0.35)

inpt: 65.18 ±16.17sda: 73.18 ±14.7(p=0.04)

surgeries’ urgency elective (e)/non-elective (ne) (n=83)

e: 63.81 ±12.02ne: 61.81 ±12.73(p=0.56)

e: 73.39 ±14.23ne: 61.31 ±16.81(p=0.004)

Table 4 Effect of Durations of Cardiopulmonary Bypass and Oximetry Monitoring

on the End Values of Tissue Oximetry at Skin Closure

Correlating factor with Correlation Coefficient (r)

Correlation of percent Change from baseline to end value

Cerebral oximetry

Correlation of percent Change from baseline to end value

renal oximetry

Cardiopulmonary bypass duration in Sevoflurane Induction Patients (n=69)

r= -0.07 (p=0.58) r= -0.003 (p=0.98)

total duration of oximetry monitoring in Sevoflurane Induction Patients (n=69)

r= 0.002 (p=0.99) r= 0.07 (p=0.56)

Cardiopulmonary bypass duration in fentanyl induction patients (n=14)

r= 0.25 (p=0.4) r= -0.22 (p=0.46)

total duration of oximetry monitoring in fentanyl induction patients (n=14)

r= 0.001 (p>0.99) r= -0.3 (p=0.3)

M.E.J. ANESTH 22 (5), 2014

461

on type of anesthesia induction (table 5). Conversely, the acquisition rates varied from 14% to 77% when patients were being compared for the differences in their cerebral oximetry vs. their renal oximetry (table 6). However, in spite of varied acquisition rates for oximetry data, the overall statistical powers were adequate (1-β ≥ 0.7) (Figures 2-5) except for

total duration of oximetry monitoring in these seven patients was less than 254 minutes with lowest duration of oximetry monitoring being 224 minutes. the acquisition rates of interspersed time-points (time-point being each instance of recorded 30-second tissue oximetry value) within the two time zones varied from 15% to 65% when patients were being compared based

Cerebral “Hyperoxygenation” witH inHalational induCtion of anestHesia in CHildren: a retrospeCtive Comparison between vasoparalytiC sevoflurane vs. vasoneutral fentanyl

Table 5 Acquisition Rate Database used before comparing Sevoflurane Induction vs. Fentanyl Induction

time Zone (for both absolute and percentage numbers)

missing data points (Cells) for Comparison between Sevoflurane and Fentanyl

induction

remaining time points (Columns) for Comparison

after removal (t)

acquisition rate [(t/254)*100]

first 127 minutes of Cerebral oximetry (n=69sevo+14fent=83)

212 (average per patient=2.55) 119 per patient 47%[figure 2(a) and figure 3(a)]

first 127 minutes of renal oximetry (n=69sevo+14fent=83)

111 (average per patient=1.34) 164 per patient 65%[figure 2(b) and figure 3(b)]

last 127 minutes of Cerebral oximetry (n=69sevo+14fent=83)

142 (average per patient=1.71) 151 per patient 59%[figure 4(a) and figure 5(a)]

last 127 minutes of renal oximetry (n=69sevo+14fent=83)

224 (average per patient=2.7) 39 per patient 15%[figure 4(b) and figure 5(b)]

Table 6 Acquisition Rate Database used before comparing/correlating Cerebral Oximetry vs. Renal Oximetry

time Zone (for both absolute and percentage numbers)

missing data points (Cells) for Comparison between Cerebral

and renal oximetry

remaining time points (Columns) for

Comparison after removal (t)

acquisition rate [(t/254)*100]

first 127 minutes of Sevoflurane Induction (n=69Cer+69ren=138)

213 (average per patient=1.54) 104 per patient 41%[figure 2(c) and figure 3(c)]

first 127 minutes of fentanyl induction (n=14Cer+14ren=28)

110 (average per patient=3.93) 171 per patient 67%[figure 2(d) and figure 3(d)]

last 127 minutes of Sevoflurane Induction (n=69Cer+69ren=138)

68 (average per patient=0.49) 195 per patient 77%[figure 4(c) and figure 5(c)]

last 127 minutes of fentanyl induction (n=14Cer+14ren=28)

298 (average per patient=10.64)

35 per patient 14%[figure 4(d) and figure 5(d)]

462 gupta d. et. al

Fig. 2 Absolute Number Changes in Tissue Oximetry over Time in the First 127 Minutes of Anesthesia

Fig. 3 Percent Changes from the Pre-Induction Baseline in Tissue Oximetry over Time in the First 127 Minutes of Anesthesia

M.E.J. ANESTH 22 (5), 2014


Fig. 4 Absolute Number Changes in Tissue Oximetry over Time in the Last 127 Minutes of Anesthesia

Fig. 5 Percent Changes from the Pre-Induction Baseline in Tissue Oximetry over Time in the Last 127 Minutes of Anesthesia

464 gupta d. et. al

comparisons of cerebral and renal oximetry in last 127 minutes time-zone for fentanyl induction patients [figures 4(d), 5(d)] where statistical powers were inadequate (1-β <0.3).

Per oximetry assessment, the final significant results as depicted in figures 2-5 were as follows: (i) cerebral and renal “hyperoxygenation” occurs during first 127 minutes with sevoflurane as compared to fentanyl [figure 2(a-b)] though percentage changes from pre-induction values in oximetry during this time did not reach level of significance [Figure 3(a-b)], and (ii) cerebral “hyperoxygenation” persisted (absolute and percentage changes) in the last 127 minutes when patients were induced with sevoflurane as compared to fentanyl [figures 4(a), 5(a)].

Discussion

as elicited in our previous case series discussion1, this current retrospective review takes the next step in confirming our hypothesis that cerebral “hyperoxygenation” occurs with inhalational induction of anesthesia with sevoflurane. This “hyperoxygenation” per cerebral oximetry may be reflecting the disproportionately increased delivery of oxygen to the cerebrum secondary to sevoflurane’s vasodilatory properties and decreased consumption of oxygen by cerebrum secondary to sevoflurane’s anesthetic properties-related decreased cerebral metabolic rates. Consequently, cerebral oxygen levels are above normal after sevoflurane induction and they remain elevated most likely due to additive (and similar) vasodilatory and anesthetic effects of slowly accumulating maintenance inhalational agents (usually isoflurane) despite dissipating vasodilatory effect of high-doses of sevoflurane used during inhalational induction of anesthesia.

in our case series discussion, this “hyperoxygenation” was termed as luxury oxygenation1 with sevoflurane as compared to cerebro-vasoconstrictive propofol. However, after completing the analysis for this retrospective review, we observed that this relative luxury oxygenation was also present (with good degree of statistical significance) when compared with fentanyl as induction agent that is considered vaso-neutral as compared to propofol

and sevoflurane. Moreover, significant cerebral “hyperoxygenation” with sevoflurane as compared to fentanyl persisted at the end of cardiac surgery as compared to insignificantly different renal “hyperoxygenation” between sevoflurane and fentanyl. this can only be explained by innate physiological differences in the way cerebral and renal (somatic) tissues behave when exposed to inhalational agents. the “hyperoxygenating” changes were unique to cerebrum compared to kidney (somatic tissue) because there were significant differences in the patterns of cerebral oximetry changes vs. renal oximetry changes over time [figures 2(c-d), 3(c-d), 4(c), 5(c)] wherein cerebral oximetry values attempted to recover back closer to pre-induction values at the end of cardiac surgery as compared to renal oximetry values that remained elevated (and higher than cerebral oximetry values) once elevated in the initial stages of the cardiac surgery. the innate physiological behavior where renal “hyperoxygenation” did not attempt to recover to baseline values at the end of the surgery as compared to cerebral “hyperoxygenation” may be possibly explained by underlying relative plasticity of renal (somatic) vasculature as compared to underlying relative dynamicity of cerebral vasculature.

although cerebral “hyperoxygenation” attempted to recover closer to baseline pre-induction values at the time of skin closure, these attempts reflecting return of cerebral vaso-reactivity were incompletely possible from the state of maximal vasodilatation induced by high doses of sevoflurane induction. Hence, it was observed that cerebral “hyperoxygenation” induced by sevoflurane was significantly different as compared to that was induced by fentanyl. although the standard of practice to use isoflurane as maintenance inhalational agent might have contributed to additional cerebral “hyperoxygenation” after induction of anesthesia with either sevoflurane or fentanyl, this additional cerebral “hyperoxygenation” could not bridge/overcome the initial differences in cerebral oxygen levels attained secondary to anesthesia induction agents (sevoflurane and fentanyl). as renal (somatic) “hyperoxygenation” behaved differently than cerebral “hyperoxygenation” by being higher at most of the analyzed time-points, it can be safely said that this “dynamic” cerebral “hyperoxygenation” cannot be attributed to forehead skin’s “plastic” vaso-reactivity to inhalational agents

M.E.J. ANESTH 22 (5), 2014


that would have been similar in time-trend patterns to “plastic” renal (somatic) “hyperoxygenation”.

although cardiopulmonary bypass and anesthesia durations did not significantly induce changes in the end values of tissue oximetry, it can be subjectively seen in figures 4(a) and 5(a) that the sudden appearance of step-up in the middle of absolute cerebral oximetry’s graph (for both sevoflurane and fentanyl) was approximate reflection of the time-frame when patients would have been weaning from cardiopulmonary bypass machine. it is interesting to observe that similar step-up was absent in the absolute renal oximetry’s graph [figures 4(b), 5(b)] suggesting that cerebral oxygenation recovery curve from cardiopulmonary bypass behave differently from renal (somatic) oxygenation recovery curve. it would have been interesting to segregate the time zones into pre-bypass, intra-bypass and post-bypass periods for evaluating any time-zone-specific tissue oximetry changes; however, the stored computerized database did not have saved snapshot times of initiation and culmination of cardiopulmonary bypass period thus precluding the division into abovementioned three time-zones for statistical comparisons.

this retrospective review has a few limitations. Although this review affirmed the presence of cerebral “hyperoxygenation” with sevoflurane, how this level of cerebral “hyperoxygenation” will affect the young patients’ brain remains unknown and un-quantified. although oxygen toxicity has been known to medical community for decades3-6 with new concerns about its relation to neuro-apoptosis7, the direct cellular and clinical effects of cerebral “hyperoxygenation” elicited per cerebral oximetry will require laboratory investigations and randomized controlled trials respectively to affirm and validate our results. Future trials will also need to comprehensively investigate

the confounding factors that were not included in our current study due to retrospective review’s logistics. these confounding factors would have been (but not limited to) presence of cardio-pulmonary shunts, sequential arterial blood gas parameters, coagulation characteristics, hemoglobin and hematocrit levels, bilirubin levels, vaso-active medications use, intracranial pathologies, and volume status of the patients.

conclusion

Cerebral “hyperoxygenation” occurs with inhalational induction of anesthesia with vasoparalytic sevoflurane in children 0 to 4 years of age when compared to anesthesia induction with vasoneutral fentanyl.

acknowledgement

the authors sincerely acknowledge the support and efforts of Henry l. walters iii, md, Chief, Cardiovascular surgery, Children’s Hospital of michigan and grant C. whittlesey, CCp, director, pediatric perfusion, Children’s Hospital of michigan in supporting this anesthesiology research by sharing computerized oximetry and recorded perfusion databases. the authors also acknowledge wayne state university anesthesiology faculty namely edward Kaminski, md, Jaspreet sangha, md and Harold michael marsh, mbbs for their input and guidance. finally, the authors acknowledge the efforts of eric nowicki, medical student during data collection and george mckelvey, phd during statistical calculations and analysis.

466 gupta d. et. al

references

1. Gupta D, sanGha J, kaminski e: inhalational induction with “vasoparalytic” sevoflurane: are we “hyperoxygenating” while anesthetizing developing brains? A case series discussion. Middle East J Anesthesiol; 2012, 21:863-7.

2. fda.gov [homepage on the internet]: silver spring, maryland: u.s. food and drug administration [updated on 2013 november 15; cited on 2013 december 22]. anesthesia: is it safe for young brains? [about 1 screen]. Available from: http://www.fda.gov/forConsumers/Consumerupdates/ucm364078.htm

3. Dickens F: the toxic effects of oxygen on brain metabolism and on tissue enzymes; tissue enzymes. Biochem J; 1946, 40:171-87.

4. ahotupa m, mäntylä e, peltola V, puntala a, toiVonen h: pro-

oxidant effects of normobaric hyperoxia in rat tissues. Acta Physiol Scand; 1992, 145: 151-7.

5. masamoto k, tanishita k: oxygen transport in brain tissue. J Biomech Eng; 2009, 131:074002.

6. allen BW, Demchenko it, piantaDosi ca: two faces of nitric oxide: implications for cellular mechanisms of oxygen toxicity. J Appl Physiol; 2009, 106: 662-7.

7. siFRinGeR m, BRait D, Weichelt u, zimmeRman G, enDesFelDeR s, BRehmeR F, Von haeFen c, FRieDman a, soReq h, BenDix i, GeRstneR B, FelDeRhoFF-mueseR u: erythropoietin attenuates hyperoxia-induced oxidative stress in the developing rat brain. Brain Behav Immun; 2010, 24:792-9.

467 M.E.J. ANESTH 22 (5), 2014

Comparison between intravenous patient Controlled analgesia and patient

Controlled epidural analgesia in CirrhotiC patients after hepatiC reseCtion

NirmeeN A. FAyed*, HAtem B. ABo el-WAFA**, NAHlA m. GAB-AllA*, KHAled A. yAsseN* ANd mAmdouH e. lotFy**

Abstract

Background: postoperative pain is one of the most important problems that confront surgical patients. the aim of this work is to compare pain control using intravenous patient controlled analgesia (pCa) and patient controlled epidural analgesia (pCea) in cirrhotic patients undergoing elective hepatic resection.

Methods: thirty four adult patients asai and ii scheduled for liver resection were randomly allocated into two groups-group (p) with i.v (pCa) with fentanyl and group (e) (pCea) via epidural catheter using bubivacaine 0.125% plus 2 microgram per ml fentanyl. Coagulation changes were followed and pain score was compared in both groups.

Results: 34 child a cirrhotic patients, undergoing liver resection were studied. the demographic data were comparable in both groups. There was a significant decrease in pain score in both groups during the follow up period when compared to their initial score. when comparing average pain score between both groups, the PCEA group had significantly lower values. The changes in prothrombin time (PT), INR, and hemoglobin (Hb), were significant all over the follow up period compared to their corresponding base line values. 2 cases needed ffp to normalize the INR for epidural removal. There was no significant difference regarding postoperative nausea and vomiting (ponv) in both groups, no clinical manifestation suggesting epidural hematoma, and no cases were recorded to have respiratory depression. There were no significant differences in patient satisfaction and iCu stay.

Conclusion: the two modalities of pain control seems to be nearly equivalent, but considering the risk of epidural catheter insertion and removal in cirrhotic patients who are further exposed to hepatectomy with subsequent additional coagulopathy, it may be wise to consider ivpCa technique as a policy for pain management in cirrhotic patient undergoing hepatectomy.

Keywords: Post-operative pain, liver resection, Patient controlled intravenus analgesia, Patient controlled epidural analgesia.

* national liver institute.** faculty of medicine. Affiliation: anaesthesiology and intensive care unit, menoufyia university, shebein al-Koom. Corresponding author: nirmeen fayed; anesthesiology and intensive care department, national liver institute, menoufyia

university, shebein al- Koom, egypt, tel: 00201113320976. e-mail: [email protected]

468 fayed n. a. et. al

Introduction

postoperative pain is one of the most important complications that confront surgical patients. the aim of postoperative pain treatment is to provide subjective comfort in addition to inhibiting trauma-induced nocioceptive impulses in order to blunt autonomic and somatic reflex responses to pain and subsequently to enhance restoration of function by allowing the patient to breathe, cough and move more easily1-3. liver resection is used with increasing frequency for treating primary neoplasms of the liver, which are frequently related to liver cirrhosis. it has been assumed that sufficient pain relief will improve the surgical outcome with reduced morbidity, need for hospitalization and convalescence1,4. postoperative analgesia in cirrhotic patients remains a challenge, mainly because of the narrow dose range between the analgesic and side effects of drugs used,1 in addition to alteration of the endogenous opioid system which have been reported in patients with liver disease2,5. epidural analgesia is one of the best methods for the provision of postoperative pain relief in patients recovering from major upper abdominal operations. being an invasive technique, epidural analgesia carries an inherent risk of several complications. also the remaining liver’s capacity to produce clotting factors is decreased for several days following resection which makes the epidural analgesia of concern3,6. among the most commonly used pain-relieving techniques is patient-controlled intravenous analgesia (pCa) with opioids which may be an attractive alternative in this category of patients in whom epidural may carry possible risks. this study aims to compare epidural versus intravenous patient controlled analgesia in cirrhotic patients undergoing hepatic reactions.

Methods

this study was approved by of the local ethical committee and a written informed consent was obtained from each patient. thirty-four patients asa i and ii, Child a cirrhotic patients, who were undergoing major liver resection, were classified into two groups:

group (p) received intravenous patient controlled analgesia (pCa) with fentanyl while group

(e) received patient-controlled epidural analgesia (pCea) with bubivacaine 0.125% plus 2 microgram per ml fentanyl. all surgeries were performed under standardized general anesthesia.

patients included in the study are of 25 years or older, not on anticoagulant therapy and undergoing major hepatic resection surgery for tumor removal. exclusion criteria included failure of the surgery to proceed as planned, development of post operative complications limiting assessment, objection to an epidural catheter or inability to use pCa pump, postoperative need for mechanical ventilation, patients having contraindication to regional technique as infection and anatomical spinal abnormality and preexisting severe pulmonary or psychiatric diseases. in group (e) epidural catheters were placed at (t11-l2) interspaces while the patient is awake before anesthesia, in sitting position using loss of resistance to air technique and a median approach using an 18g touhy needle and a 20g epidural catheter after negative suction of blood and cerebrospinal fluid. A test dose of lidocaine 2% (total test dose of 3ml) was injected. all pCea pumps were programmed for a basal infusion rate of 6 ml/hr and a patient-activated bolus of 3ml every 15 minutes. All PCEA were initiated within first 2 hours after induction at a basal rate only.

patients in group (p) with ivpCa were well educated about the pump with detailed description of the plan of pain management. an i.v line was inserted and fentanyl 15 μg bolus was injected with 10 min lock out interval, 90 μg/hr maximum and no back ground infusion.

general anesthesia was induced on for all patients with fentanyl (1-2 μg/kg), propofol (1-2 ml/kg), and rocronium (0.6 ml/kg) and after intubation anesthesia was maintained with isoflurane in a 50% oxygen-air. iv muscle relaxant was administered as appropriate.

intra operative monitoring included eCg, pulse oximetry, capnography, fraction of inspired o2, body temperature, urine output, central venous pressure (C.v.p), and blood pressure. tidal volume and ventillatory rate were adjusted to maintain end tidal Co2 between 35-40 mmhg. intra operative hypothermia was prevented by forced air surface warming (model 750-bair hugger temperature management unit, arizant healthcare inc, usa).

M.E.J. ANESTH 22 (5), 2014

469Comparison between intravenous patient Controlled analgesia and patient Controlled epidural analgesia in CirrhotiC patients after hepatiC reseCtion

at the end of surgery, all patients were awakened and extubated in the operating room and transferred to the surgical intensive care unit. data collected included age, sex, surgery performed, length of surgery, intraoperative blood products requirements, hospital and i.C.u. length of stay and day of epidural catheter removal. epidural catheters were removed when platelet count was more than 80 x 109 and inr <1.4. all patients were contionously observed for clinical signs of spinal cord compression. blood tests, including complete blood count, prothrombin time (pt), activated partial thromboplastin time, were determined preoperatively, immediately on admission to the recovery room and the third postoperative day (pod).

base line heart rate and non-invassive blood pressure were continuously monitored.

post operative pain was assessed by a10cm visual analogue scale (vas) (0 to 10) 0 no pain, and 10 worst pain at rest and during movements (inspiration and cough). side effects such as nausea, vomiting and were also noted.

the primary out-come was to compare both techniques regarding pain control. secondary outcomes included evaluation of complications such as sedation, nausea, vomiting, urinary retention, post operative pulmonary complications, epidural neurological complications, return of bowel function and the length of intensive care and hospital stay.

Statistical procedure

data was statistically analyzed using spss (statistical package for social science) program version 13 for windows and epi info program version for all the analysis a p value <0.05 was considered statistically significant:

- data are shown as mean, range or value and 95% confidence interval (95% CI) and frequency and percent.

- fischer exact test for 2 × 2 tables when expected cell count of more than 25% of cases was less than 5 and p-value <0.05 was considered significant.

- student t-test was done for normally distributed quantitative variables to measure mean and standard

deviation and p-value <0.05 was considered significant.

- mann-whitney test was done for quantitative variables which are not normally distributed and p-value <0.05 was considered significant.

- paired t test was done to detect mean and standard deviation of normally distributed pre and post values of the same variable of the same group of patients and p-value <0.05 was considered significant.

- wilcoxon test was done to detect mean and standard deviation of not normally distributed pre and post values of the same variable of the same group of patients and p-value <0.05 was considered significant.

- repeated measures anova test was performed to differentiate changes in different follow up results of normally distributed studied variables and p-value <0.05 was considered significant.

- friedman test was performed to differentiate changes in different follow up results of different studied variables and p-value <0.05 was considered significant.

all data are tested with kolmogorov-smirnov Z test and most of them were found normally distributed and so presented with mean ± sd; and using parametric testes on doing association or correlation.

17 patients in arm 1 with intravenous pCa and 17 patients in arm 2 with pCea were recruited based on the following assumptions: with the power of 80 %, α = 0.05 and the ratio of cases to controls = 1:1. The required sample size was determined using ps (power and sample size calculation) software.

Results

patients’ characteristics and operative data are shown in table 1. the mean arterial blood pressure and heart rat tended to be better controlled in ivpCa group however the comparison was statistically insignificant (P value >0.05) when comparing both groups. pCea and iv pCa were found to be similar and effective in pain control at rest during the first three days postoperatively, mean intensity of pain on a numerical analogue scale (0-10) at rest on day 1 was 5/10, day 2 was 3/10, and day 3 was 2/10, but on cough both groups suffered out breaks of pain on


first day that needed intravenous meperidine. On day 2 and 3; patients of pCea group suffered less pain during cough (table 2). postoperative sedation score showed significant difference between both groups during the first day followed by a significant mean

decrease in score by 2nd and 3rd days post operatively in the ivpCa group (table 3). four out of 17 cases in the epidural group complained of bilateral lower limb numbness during the first postoperative day in the pCea group, due to the established epidural block, but only one patient developed moderate motor block and in this sole case the epidural infusion was stopped with close follow up of the motor status. regarding the coagulation changes, there was significant increase in inr and prothrombin time, with peak changes at the 3rd POD with no significant changes in platelets count when compared to corresponding base line values in both groups. the mean time for the epidural catheter stay was 5.88 ± 1.27 days before removal; two cases demanded the infusion of fresh frozen plasma units before removal in order to achieve acceptable level of the prolonged prothrombin time and elevated inr. patients in the pCea group were less sedated and had fewer incidences of side effects as nausea/vomiting.

Table 1 Patient characteristics (mean +/- SD)

IVPCA(n = 17)

PCEA(n = 17)

age (years) 50.1 +/- 9.7 50.8 +/- 11.5

sex (m/f) 10/7 15/2

weight (Kg) 81.7 +/- 15.7 78.8 +/- 14.8

type of operation (n / %)

right hepatectomy (focal lesion)

6/35.3 10/58.8

right hepatectomy + left radiofrequency (focal lesion)

3/17.6 0/0

left hepatectomy (focal lesion)

6/35.3 4/23.5

right hepatectomy (Cyst)

2/11.8 1/5.9

left hepatectomy (hydatid)

0/0 1/5.9

right hepatectomy (haemangioma)

0/0 1/5.9

data are presented as mean +/- sd, student t-test was used comparing age, weight, intensive care unit; iCu stay between groups; p >0.05 considered not significant.

Table 2 Post-operative pain score on cough Mean +/- SD

Time IVPCA (n = 17) PCEA (n = 17)

2hrs pod1 3.18 0.81 3.82 (1.13)

8hrs pod1 6.35 (0.78) 6.59 (0.79)

12hrs pod1 6.76 (0.66) 7.00 (0.71)

24hrs pod1 6.61 (0.69) 6.29 (0.68)

pod2 6.59 (0.94) 5.65 (1.22)*

pod3 6.00 +/- 1.12 4.47 +/- 1.26**

data are presented as mean +/- sd, student t-test was used for postoperative pain score, *P <0.05 is considered significant and **P <0.01 is considered highly significant, POD; postoperative day.

Table 3 Sedation score of both groups on POD1

Studied variables

Groups Mean +/ - SD

Sedation score ivpCa 3.6 (0.51)

pCea 2.94 (1.14)*

data are presented as mean (sd), mann whitney test was used comparing sedation score, pod1; postoperative day 1,* P <0.05 was considered significant.

Table 4 Drug consumption differences all over the follow up period in intravenous fentanyl patient controlled analgesia group

(IVPCA)

Studied variable D1 D2 D3

Fentanyl (µg) 1255.6 (287.2)

1318.3 (413.3)*

1163.1 (398.5)**

Bolus number 121.3 (26.4)

136.3 (31.7)*

112.6 (23.2)*

Demand number

83.7 (19.1)

85.2 (28.1)

77.9 (25.9)

paired t-test was used in fentanyl, bolus and demand to study differences, * indicates statistically significant difference (P <0.05) and ** indicates highly significant difference (P <0.01).

M.E.J. ANESTH 22 (5), 2014

471

there was an increase in the amount of fentanyl used by patients in the ivpCa group by the second day post operatively followed by a decrease in the third day, matching with the pCa boluses and demands trends. the demand (number of button pushes by the patient) increase in the second day post operatively followed by a decrease in the third day, as shown in table 4. table 5 data presented the amount of bubivacaine and fentanyl used by the patients in the pCea group throughout the follow up period. No significant difference as regard the satisfaction assessment of both groups was reported (table 6).

Comparison between intravenous patient Controlled analgesia and patient Controlled epidural analgesia in CirrhotiC patients after hepatiC reseCtion

Discussion

The main finding of our study was that both PCEA and iv pCa can provide complete control of pain at rest; however, upon movement and coughing pCea was superior to iv pCea. finally, both techniques were equivalent as to patients’ satisfactions.

in this study, the pain control was effective and similar during the first postoperative day between pCea and iv pCa groups, but during movement and on cough both were not efficient enough to control the pain, which mandates use extra analgesic supplementation in both techniques. both groups required the use of analgesia by the second day more than the first day that may be due to the decline of the residual anesthetic effect and/or the increased frequency of movement and physiotherapy during the second day. by the third day the need for analgesia decreased in both groups and this could be attributed to the normal sequel of the decrease in the stress response.

the pCea group showed a gradual decrease in vas score on movement during the follow up period on the 2nd and 3rd post operative days, with less bolus and less demands, but still intravenous opioids were needed to cover for the pain outbreaks for several patients.

no sole technique was able to provide a full pain relief. a multimodal approach in the form of intravenous pethedine and paracetamol was implemented to control pain in 6 out of 17 cases in pCea group and in 8 out of 17 cases in ivpCa group. the need for supplementary intravenous opioid with pCea is supported by revie eJ et al7 who found that 20% of patients undergoing open liver resection with epidural analgesia for postoperative pain requested additional intravenous opioids for pain control.

the use of continuous background infusion in the pCea group in this study to reduce the pain on day 2 and 3 was reported also by Komatsu et al and vercauteree et al who found that the use of a background infusion of a mixture of bupivacaine and fentanyl reduced the incidence of postoperative pain significantly in particular the pain associated with cough and movement after upper abdominal surgery8.the option of using a back ground infusion of fentanyl in the ivpCa group was omitted for fear of

Table 5 Drug consumption differences all over the follow up period in

patient controlled epidural analgesia (PCEA)

Studied variable

D1 D2 D3

marcaine (ml) 352.6 (101.5)

411.6 (183.7)**

362.4 (92.1)

Fentanyl (μg) 575.5 (133.1)

628.6 (119.2)**

577.4 (172.8)

bolus 107.6 (21.2)

99.5 (21.9)

87.4 (27.7)**

demand # 60.9 (17.8)

55.5 (24.3)

52.7 (18.6)

data are presented as mean (sd), repeated measures anova test was used for marcaine, fentanyl and bolus, P <0.01 was considered highly significant. # Wilcoxon test was used for demand. paired t-test was used in bubivacaine, fentanyl and bolus to study differences with day 1, P <0.05 was considered significant.

Table 6 Satisfaction score analysis differences between patients of both

groups

satisfaction score ivpCa pCea

excellent 2 (11.7) 4 (23.5)

good 7 (41.2) 8 (47.1)

fair 8 (47.1) 5 (29.4)

poor 0 (0.0) 0 (0.0)

data are presented as number (%), Chi square test; X² was used, P-value >0.05 was considered not significant.


side effects in particular respiratory depression in this group of cirrhotic patients undergoing liver surgery and expecting a possible temporary postoperative liver dysfunction as reported previously10.

previous studies reported effective pain control when a multimodal approach for post-operative pain control was adopted11,12.

Katz et al13 added intrathecal morphine and fentanyl with bupivicaine for post-operative pain control and achieved better results with reduction in iv morphine consumption postoperatively. but, as reported by several previous studies, pain management of post liver resection is sometimes difficult to control and out breaks of pain can be reported in particular with early ambulation and physiotherapy which will need additional iv opioids, but the rate of consumption is significantly reduced if a planned multimodal analgesic technique is adopted14. the relatively less pain score in pCea group compared with ivpCa group may also be due to the combined use of local anesthetic with opioid. brodner et al15 reported that the production of the proinflammatory cytokines IL-1ß and il-6 was more increased in the intravenous pCa group compared with the pCea group, especially at 24 hours after surgery. this may be attributed to the local anesthetics effect which can reduce the postoperative inflammatory response in two ways: first blocking neural transmission at the site of tissue injury and thus may attenuate the neurogenic inflammation, second, having systemic anti-inflammatory properties of their own. this has been proved through reducing the postoperative inflammatory index in patients with continuous epidural analgesia, consisting of local anesthetics and opiates16.

the use of an epidural catheter in patients undergoing resection remains controversial because of the postoperative changes in the coagulation profiles of these patients suffering from hepatic cirrhosis which are further aggravated by the effect of liver resection.

the prolongation of the prothrombin time and increase in inr were reported in this study, inr increased gradually till the third day and began to normalize by the fifth or the sixth day, which delayed the epidural removal till the 5th and even the 7th day postoperatively in some cases. two cases needed fresh frozen plasma to help reduce inr to an acceptable

level allowing epidural catheter removal. none of the cases developed any clinical manifestation suspecting epidural hematoma or showed signs of neurological deficits.

these results were similar and in agreement with the study by schumann et al17 which also showed a transient postoperative coagulopathy after liver resection among their healthy liver patients.

matot i et al18 also showed the same findings with a conclusion that the extent of liver resection may affect the magnitude and duration of postoperative coagulation disturbances and, therefore, they concluded that the proper timing of epidural catheter removal need also to be revised with the coagulation laboratory results day by day before removal.

tran sb et al19 also documented that in healthy livers subjected to minor liver resection the pt returns to a normal value in one to two days, while in major resection it might need up to 5 days to normalize. all the previous factors may account for a delay of removal of the epidural catheter until day 7 and for the need for fresh frozen plasma transfusion in some cases as reported by the current study and the study of tran sb.

most of cases in this study started oral sips of water and juice by the 1st day post operatively. the incidence of nausea and vomiting in this study was (3/17) in the ivpCa group and (1/17) in the pCea group, few cases needed medical intervention for symptomatic relief, this may be attributed to the choice of using fentanyl in both groups which is known to have a lower incidence of post operative nausea and vomiting than morphine. this was in agreement with Koo pJ, et al20 and rob et al21. studies which found that IV PCA fentanyl have a significant lower rate of common opioid side effects (nausea/vomiting) when compared to other methods of analgesia.

in contrast, bozkurt p et al22 has reported a higher incidence of nausea and vomiting in children after epidural opioids of approximately 30%, and 87% with iv pCa.. this higher incidence may be due to the different patient populations. this age category variation in incidence was supported by leman et al23 who reported that children have an average vomiting incidence more than 40% almost twice as frequent as the rate in adults and the incidence tapers by reaching puberty.

M.E.J. ANESTH 22 (5), 2014


epidural analgesia with local anesthetics offers potential means to attenuate several mechanisms of postoperative ileus. sympathetic block from epidural local anesthetics may help attenuate postoperative reflex inhibition of GI motility. Suppression of the surgical stress response and systemic absorption of epidural local anesthetics may reduce the inflammatory response and attenuate the postoperative ileus. both postoperative pain and use of systemic opioids increase the risk of ileus. in Consistent with these mechanisms, experimental data indicates that epidural analgesia with local anesthetics shortens time of intestinal paralysis, increases the strength of colonic contractions, and does not impair anastomotic healing or increase risk of anastmotic leakage24,25.

the level of the epidural catheter was intended to be thoracic to keep its tip in the target dermatome for perfect pain control especially with using fentanyl, sparing of lumbosacral segments to minimize urinary retention and limit motor effects as reported by basse et al26.

in this study, urinary retention as an expected complication could not be assessed due to the presence of a urinary catheter.

in agreement with veering bt et al study27, patients in the epidural group showed better control of systolic blood pressure and heart rate than in the ivpCa group, which may be due to a better pain control.

respiratory depression in patients undergoing major upper abdominal surgery is of great concern due to impaired of diaphragmatic, intercostal, and abdominal muscle functions and in case of inadequate analgesia the tidal volume will be also further reduced, hence an adequate pain control is of a major priority. in this study we did not record any manifestations of respiratory depression as assessed by continuous monitoring of respiratory rate, oxygen saturation, and degree of consciousness in both groups and no naloxone was required.

in the study by wu Cl28 epidural modality conferred superior analgesia compared with that from systemic opioids including ivpCa, which may improve voluntary respiratory function. segmental block from thoracic epidural anesthesia may result in increased tidal volume and vital capacity related in

part to improved pain control and also to interruption of the reflex inhibition of phrenic nerve activity, thus improving diaphragmatic activity. however, effects from the typical dilute solutions of local anesthetics and opioids used for thoracic epidural analgesia (tea) are unclear. it has also been demonstrated that tea with bupivacaine 0.25% does not impair ventilatory mechanics, respiratory muscle strength, or airway flow even in patients with severe chronic obstructive pulmonary disease29.

various degrees of sedation in the post-operative period in cirrhotic patients have to be expected due to use of opioids. our patients were closely monitored with sedation score. There was a significant degree of sedation all over the study period in both groups with highest score during the 1st day which could be attributed to the residual effect of the general anaesthetic agents and intra operative opioids used, the following declining in scores was associated with a decrease in severity of pain during the following postoperative days and subsequent decrease in drug consumption. trends of sedation were higher in ivpCa group as expected with the use of iv opioids, with no recorded deep sedation as indicated by absence of any manifestation of respiratory depression. butkovic, et al30 found that the type of analgesia either ivpCa or pCea has no effect on the ramsay sedation score, implying that both analgesic regimes produced the same level of sedation, however, a meta-analysis of several different studies found less respiratory depression with administration of continuous epidural opioids compared with parentral opioids31.

in order to encourage early mobilization and achieve patient satisfaction and pain relief, a local anesthetic concentration of 0.125% was used in pCea group to reduce possible motor weakness, however 4 out of 17 cases complained of bilateral lower limb numbness on the first postoperative day. Only one patient developed moderate motor block and the epidural infusion was stopped with close follow up of the motor status. Christopher32 reported better pain relief at the expense of higher incidence of motor block with the use of continuous epidural analgesia compared with pCea. John et al33 correlated the density and duration of block with the concentration of the local anesthetic as both the 0.125% and 0.25%


groups had significantly denser maximum motor blockade than the 0.0625% group, indicating a degree of dose-dependent response. in this study the effect of various concentrations of bupivacaine was not evaluated, as the study was restricted to one protocol; however pain control and degree of motor and sensory block were acceptable.

in a study by pitimana et al34, the satisfaction analysis indicated excellent score in 11%patients of ivpCa and 23% of pCea group undergoing total knee replacement, this difference may be because of the ability of epidural analgesia to promote patient well being in the form of better pain control particularly on movement, faster recovery of bowel function and earlier patient mobility, but this did not alter the iCu stay when compared to the pCa group35.

in another study by butkovic et al30 ivpCa with fentanyl was as effective as epidural block with bupivacaine and fentanyl in controlling the postoperative pain of children after thoracoscopic surgery for pectus excavatum repair.

One study found no significant differences in patients’ satisfaction after living donor liver resection in those receiving either ivpCa opioids or pCea, also the authors warned from the post operative coagulopathy that may affect the removal of the catheter36.

in our study, there was no evident clinical significance between the two techniques regarding the efficacy in pain control during rest, but not on

movement. there were no differences as well in the severity of any complications including sedation, respiratory and git side effects apart from sedation during the first day post operatively. In view of the choice of a safer method to control pain in cirrhotic patients it may be wise to recommend ivpCa in order to avoid the remote incidence of epidural hematoma which may be more prevalent with post liver resection associated coagulopathy particularly when it is not possible to assess the neurological condition of the patients during the long hours of the surgery until recovery.

one of the limitations of the current study is the inability to alter the settings of the pCa pumps for both groups during the course of the study period and the inability to modulate the bupivacaine concentration. also, the use of background infusion in cirrhotic patients and their safety need to be studied in further planed research work. Conclusion: ivpCa with fentanyl was used with no reported side effects in Child a cirrhotic patients. also, pCea was delivered safely with no clinical evidence of epidural hematoma, but in view of the associated coagulation changes in conventional tests, it seems wiser to recommend the ivpCa opioids for cirrhotic patients. a multimodal approach is recommended as no sole technique was enough to control out breaks of pain for such a surgical procedure. each patient should be informed and consented before surgery about pros and cons of the two techniques and risks weighed against benefits.

M.E.J. ANESTH 22 (5), 2014


References

1. CreWs JC: Multimodal pain management strategies for office-based and ambulatory procedures. JAMA; 2002, 288:629-632.

2. tANAKA s, norio noGucHi f, ocHiAi t, et Al: outcomes and recurrence of initially resectable hepatocellular carcinoma. meeting milan Criteria: rationale for partial hepatectomy as first strategy. Journal of the American College of Surgeons; January 2009, vol. 204, 1-6.

3. scHecter wp, boNGArd fs, gAiNor bJ, weltz dl, horN JK: pain control in outpatient surgery. JAM CollSurg; 2002, 195:95-104.

4. Cross, sa: mayo Clin pathophysiology of pain. this article on pain mechanisms is still by far the best summary we have. Anesth Analg; 2003, 96:548-54.

5. mAddAli mm, mAtHeW J, fAHr J, et Al: a prospective study of postoperative nausea and vomiting in a tertiary care hospital in oman. Middle East J Anaesthesiol; 2003, 17:131-41.

6. breeN tw, et Al: epidural anesthesia for labor in anambulatory patient. Anesth Analg; 1993, 77:919-24.

7. revie eJ, mAssie lJ, mcNAlly sJ, et Al: effectiveness of analgesia after liver resection. Reg Anaesth Pain Med; 2010, 35:51-60.

8. KomAtsu h, mAtsumoto s, mistuHAtA h, et Al: Comparison of patient controlled epidural analgesiawith and without background infusion after gasterectomy. Br J, Anaesth; 2001, 87:907-10.

9. vercAutereeN mi, CoppejANs hC, broecKe pw, et Al: epidural sufentanil for postoperative patient-controlled analgesia (pCa) with or without background infusion: a double-blind comparison. Anesth Analg; 1995, 80:76-80.

10. flisBerG p, rudiN a, liNNer r, luNdBerG CJf: pain relief and safety after major surgery.a prospective study of epidural and intravenous analgesia in 2696 patients. Acta Anaesthesiol Scand; 2003, 47:457-65.

11. ozAlp g, guNer f, Kuru n, et Al: postoperative patient-controlled epidural analgesia with opioid-bupivacaine mixtures. Can J Anaesth; 2010, 45:938-942.

12. miNG h, CHeN K, KWANG m, et Al: the addition of morphine prolongs fentanyl-bupivacaine spinal analgesia for the relief of labor pain. departments of anesthesiology and gynecology and obstetrics, national taiwan university hospital, taiwan. Anesth Analg; 2001, 92:665-8.

13. KAtz J, CoHeN l, scHmid r, CHAN vw, woWK a: postoperative morphine use and hyperalgesia are reduced by preoperative but not intraoperative epidural analgesia: implications for preemptive analgesia and the prevention of Central sensitization. Anesthesiology; June 2003, 98:1449-1460.

14. bAjWA sJ, bAjWA sK, KAur J, et Al: admixture of clonidine and fentanyl to ropivacaine in epidural anesthesia for lower abdominal surgery, department of anaesthesiology and intensive Care, gian sagar medical College and hospital, india. Anesth Essays Res; 2010, 4:9-14.

15. brodNer g, vAN aKeN h, hertle l, et Al: multimodal perioperative management-combining thoracic epidural analgesia, forced mobilization, and oral nutrition-reduces hormonal and metabolic stress and improves convalescence after major urologic surgery. Anesth Analg; 2001, 92:1594-60.

16. pAGe gg, blAKely wp, beN-eliyAHu s: evidence that postoperative pain is a mediator of the tumor-promoting effects of surgery in rats. Pain; 2001, 90:191-9.

17. scHumANN r, ZABAlA l, aNGelis m, et Al: altered hematologic

profiles following donor right hepatectomy and implications for postoperative analgesic management. Liver Transpl; 2004, 10:363-87.

18. mAtot i, scHeiNiN o, eid a, Jurim o: epidural anesthesia and analgesia in liver resection. Anesth Analg; 2002, 95:1179-81.

19. trAN sb, wellmyer e, gAdAssAly sr, steAdmAN rh: postoperative coagulation status following liver donor-living transplantation. Anaesthesiology; 2001, 95:a186.

20. Koo pJ: postoperative pain management with a patient-controlled transdermal delivery system for fentanyl. Am J. Health Syst Pharm; 2005, 62:1171-1176.

21. roB w, hutcHisoN d, CHoN e, et Al: Comparison of a fentanyl, morphine, and hydromorphone patient-Controlled intravenous delivery for acute postoperative analgesia. Br J Anaesth; 2006, 41:659-663.

22. bozKurt P: The analgesic efficacy and neuroendocrine response inpaediatric patients treated with two analgesic techniques: using morphine-epidural and patient-controlled analgesia. Paediatric Anaesthesia; 2002, 12:248-54.

23. lermAN J: surgical and patient factors involved in postoperative nausea and vomiting. Br J Anaesth; 1992, 69:s24-32.

24. groeBeN h, scHAFer b, pAvlAKovic g, et Al: lung function under high thoracic segmental epidural anesthesia with ropivacaine or bupivacaine in patients with severe obstructive pulmonary disease undergoing breast surgery. Anesthesiology; 2002, 96:536-41.

25. fotiAdis rJ, bAdvie s, westoN md, alleN-mersH tg: epidural analgesia in gastrointestinal surgery. Br J Surg; 2004, 91:828-41.

26. bAssel, liNdA m, werNer, mAds m, KeHlet: is urinary drainage necessary during Continuous epidural analgesia after Colonic resection? Regional Anesthesia & Pain Medicine; 2000, 25-5:498-501.

27. veeriNG bt, CousiNs mJ: Cardiovascular and pulmonary effects of epidural anaesthesia. Anaesth Intens Care; 2000, 28:620-35.

28. wu Cl, CoHeN sr, ricHmAN Jm, et Al: Efficacy of postoperative patient-controlled and continuous infusion epidural analgesia versus intravenous patient-controlled analgesia with opioids: a meta-analysis. Anesthesiology; 2005, 103:1079-88.

29. evA m, gruBer, eddA m, tscHerNKo, meiNHArd KritziNGer, eleNA deviAtKo, wilFried wisser, dAvid ZurAKoWsKi, wolFrAm hAider: the effects of thoracic epidural analgesia with bupivacaine on ventilatory mechanics in patients with severe Chronic obstructive pulmonary disease. Anesth Analg; 2001, 92:1015-9.

30. butKovic1 d, KrAliK1s, mAtolic1 m: postoperative analgesia with intravenous fentanyl pCa versus epidural block after thoracoscopic pectusexcavatum repair in children. Journal of Anaesthesia; 2007, 98 (5):677-81.

31. CArvAlHo b, wANG p, CoHeN se: a survey of labor patient controlled epidural anesthesia practice in California hospitals. Int J Obstet Anesth; 2006, 15:217-22.

32. CHristopHer l, CoHeN M: Efficacy of Postoperative Patient-controlled and Continuous infusion epidural analgesia versus intravenous patient-controlled analgesia with opioids: a meta-analysis. Anesthesiology; november 2005, 103:1079-1088.

33. JoHN a, murdocH C, ursulA K, et Al: The Efficacy and Safety of three Concentrations of levobupivacaine administered as a Continuous epidural infusion in patients undergoing orthopedic surgery. Anesth Analg; 2002, 94:438-444.


34. pitimANA-aree s, visAlyAputrA s, Komoltri C, et Al: an economic evaluation of bupivacaine plus fentanyl versus ropivacine alone for patient-controlled epidural analgesia after total knee replacement procedure: a double blinded randomized syudy. Regional anesthesia and pain management; 2005, 30:44-451.

35. orHAN-suNGur m, KrANKe p, sessler d, apFel C: does supplemental

oxygen reduce postoperative nausea and vomiting? a meta-analysis of randomized controlled trials. Anesth Analg; 2008, 106:1733-8.

36. JeAN-deNis r, luc mAssicotte a: Comparison of intrathecal morphine/fentanyl and patient-Controlled analgesia with patient-Controlled analgesia alone for analgesia after liver resection. Anes Analg; 2006, 103:990-994.

477 M.E.J. ANESTH 22 (5), 2014

Simulation training in EndotrachEal intubation in a PEdiatric rESidEncy

Rana ShaRaRa-Chami*, SahaR TaheR**, Roland Kaddoum***, hani Tamim**** and lama ChaRafeddine*

Abstract

Background: airway management and endotracheal intubation are essential skills for pediatric residents. Simulation-based technology is used for training residents but it remains unclear whether high fidelity simulation results in better retention of skills compared to low fidelity. The study assesses high fidelity simulation of endotracheal intubation and traditional low fidelity training in improving pediatric residents’ knowledge retention and technical skills; and if the difference translates into higher “real time” intubation success rates.

Methods: Second and third year pediatric residents were randomized into high fidelity (intervention) or low fidelity simulation (control) groups. Airway management and intubation skills were taught using a didactic lecture and demonstration on low fidelity mannequins. Knowledge was assessed before randomization (T0) and 6 months after training (T6). Other outcome measures were: 1) airway management and intubation skills at T6 and T12 (12 months later) and 2) successful intubation of actual patients by T12.

Results: 10 out of 11 residents completed the intervention. Theoretical knowledge improved for both groups. Participants made less mistakes (M) overtime: M (T0) =3.2 and M (T6) =2.6 for the intervention group, and M (T0) =4 and M (T6) =2.40 for the control. There was no significant effect of fidelity on intubation skills or the number of successful intubations recorded in logbooks (all p >0.05). In some instances intubation skills showed regression over time.

Conclusion: High fidelity simulation showed no impact on residents’ airway management and intubation skills. Retention of theoretical knowledge persisted over time while practical skills remained at baseline or declined.

Keywords: simulation, resident education, intubation skills, knowledge assessment.

* MD, Department of Pediatrics and Adolescent Medicine.** BA, Department of Psychology.*** MD, Department of Anesthesia.**** PhD, Department of Internal Medicine, Biostatistics Unit, Clinical Research Institute; Affiliation: American University of

beirut. Corresponding author: Lama Charafeddine, MD, FAAP; Department of Pediatrics and Adolescent Medicine; American

University of Beirut Medical Center; P.O. Box: 11-0236. Riad El-Solh 1107 2020; Beirut-Lebanon. Tel: +9611350000. E-mail: [email protected]

478 Sharara chami r. et. al

Introduction

Pediatric airway management is one of the most difficult skills to acquire during residency. It includes bag-mask ventilation, laryngoscope handling and endotracheal intubation skills. most cardiac arrests in infants are respiratory in origin. of those children who experience cardiac arrest in a clinical setting, 75% to 80% survive while those who do not receive proper intervention have a 5% chance of survival along with a heavy toll of neurological damage1. Airway management is therefore a life-saving and necessary skill and is an integral part of pediatric training2. Many factors may contribute to a deficient intubation. Inexperience or improper management of the airway can cause the patient’s condition to deteriorate, not the mention the negative effect of the stressful clinical setting. the success of an intubation might therefore also require practice in a comfortable and non-threatening environment where patients are not at risk so that trainees are more confident in real-life situations.

Residents report feeling inadequately prepared when it comes to managing such stressful situations in the clinical setting. at the beginning of their residency, residents take the Pediatric Advanced Life Support (PALS) and Neonatal Resuscitation Program (NRP)3,4,5,6. these educational programs help with standard training. However, studies have shown that after one year, retention of knowledge and practical skills are poor7, and airway intubation skills tend to deteriorate within a few weeks if not practiced3. in fact, Nadel et al7 showed that, one year after taking PALS only 18% of residents could effectively perform and succeed at an endotracheal intubation. other studies suggest also that PALS training is insufficient for providing residents with the adequate skills, competence and self-confidence to perform successful resuscitations3,7,8,1.

Educational programs such as PalS and nrP offer codes of conduct according to situations but have shown to come short in building solid skills for the clinical setting. Furthermore once trained, the residents do not receive many opportunities to practice their skills due to the relative infrequency of such pediatric cardiac arrest in the clinical setting.

the need for endotracheal intubation is unlikely to arise when treating children and the limited residency training hours make it difficult to acquire expertise in intubation3,6.

In order to address this need, new educational tools based on simulation or high-fidelity training have been used to enhance airway management and intubation skills of residents. High-fidelity medical simulation replicates a clinical scenario and helps standardize the procedure for the individual practicing his or her own procedural and decision making skills within a productive anxiety level conducive for learning1,9. the created environment serves as an acceptable substitute for the actual clinical setting. In this environment, residents are given the opportunity to experiment through trial and error, retry, and practice without unfavorable outcomes. Simulation training permits and builds upon a process of learning derived from concrete experience5, laying foundations for residents to practice in a supervised, standardized and patient-safe setting10. it allows for retention of knowledge through practice, and enhances the resident’s sense of mastery, competence and efficacy11.

Some studies show that residents who were taught Advanced Cardiac Life Support using high-fidelity simulation training performed better than their counterparts who received solely conventional training12,13,14. While there is some evidence that clinical skills are retained for a year after a single simulation training session8, it is not clear whether improved skill performance during simulation translates into better performance during actual patient care.

The purpose of this study was to investigate whether training of pediatric residents using high fidelity simulation would result in retention of knowledge and improved performance during actual patient care, as compared to the traditional model of teaching at the American University of Beirut Medical Centre (AUBMC).

Methods

Study design

Pilot, randomized controlled.

M.E.J. ANESTH 22 (5), 2014

479Simulation training in EndotrachEal intubation in a PEdiatric rESidEncy

Setting

Pediatric residency program at a tertiary care center, the American University of Beirut Medical center.

This study was approved by the Institutional Review Board of the American University of Beirut and all residents signed a detailed informed consent before participating in the study.

Participants

Pediatric residents in their second and third years were recruited to take part in the study. Eleven consented of which only ten completed the study. Residents had completed the Pediatric Advanced Life support (PALS) course and the American Academy of Pediatrics Neonatal Resuscitation Program (NRP) course in their first and second year of residency respectively. Those who consented to participate were randomized to either receive traditional teaching (low fidelity assessment method) (N=5) or high fidelity simulation training and assessment (N=6) in airway management. None had participated in a high-fidelity simulation scenario involving endotracheal intubation prior to the study. Residents had diverse backgrounds, some having completed their medical studies in the same institution while others from different institutions in the same country and other arab countries.

Inclusion/Exclusion

all residents in their second and third year were invited to participate in the study. Those who did not consent were excluded.

Process

a didactic lecture entitled “Pediatric airway management” was presented to all. in order to assess theoretical knowledge at baseline, all residents were given a pretest before beginning the lecture. The pretest was devised as eleven multiple-choice and true/false questions that were adapted from the official American academy of pediatrics nrP and PalS courses. after collecting the pretest, the residents were given the

lecture in addition to a demonstration of an intubation procedure performed on a low fidelity pediatric mannequin. This lecture was based on information found in “The Textbook of Pediatric Intensive Care”15, the american academy of Pediatrics and the american heart association resuscitation recommendation (Pediatric Advanced Life Support). It covered topics on airway anatomy, basic airway management, intubation technique and the equipment needed.

After completion of both pretest and lecture, informed consent forms were distributed and collected. only pretests of those participating in the study were kept.

Intervention

The two groups were invited into the simulation lab for a first hands-on training session at T0 (beginning of study), a second training session at T3 (3 months later) and one last assessment at T6 (6 months later). The two hands-on training sessions, at T0 and T3 gave the participants ample time to deliberately practice. both groups were exposed to one and the same environment and used the available equipment, including the same mannequin (SimBaby the advanced infant patient simulator from laerdal and the Simbaby software Version 1.4.1 EN produced in 2007 both acquired by HSON in 2009). The mannequin was plugged into the modem and monitor for the experimental group, hence becoming a high-fidelity mannequin.

T0 session: The first session proceeded in different steps. Each participant was individually invited to the lab for a session of 30 minutes. The participant was first asked to properly cite the equipment needed for an intubation of a 6 to 8 month old infant and to then prepare the material in order to commence the procedure. the participant was allowed to practice intubations with direct feedback by a physician expert in pediatric airway management and high-fidelity medical simulation (RSC and LC). Two scenarios were then given in which a final intubation was needed. The traditional group had the vital signs and physical exam findings read out by the present supervisor, while the experimental group used the high fidelity mannequin. The scenarios were videotaped without face identification.


logbooks were then distributed to all participating residents. residents were asked to log in their book each intubation procedure whether successful or not. This measure served as a means to follow up on each resident to compare the intubation success rate in actual clinical settings. The logbooks would be collected 6 months later.

T3 session: a training session was scheduled 3 months later (T3). Residents were invited to the simulation laboratory to deliberately practice a minimum of 10 intubations. the control group practiced on the low fidelity mannequin while the experimental group practiced on the high-fidelity mannequin. No scenarios were given.

T6 session: The final phase of the study consisted of a final hands-on session similar to the first. Scenarios were read according to each group’s assignment. The scenarios were videotaped without face identification. After completing both scenarios, supervisors debriefed participants and gave them feedback on their performance. the residents were asked to reflect on their own performance by watching it on videotape. They were given the opportunity to express their feelings and thoughts, contemplating corrective actions. A posttest was finally given to all participating residents, and the logbooks were collected (Figure 1).

Data Collection

A pediatric anesthesiologist (R.K), blinded to the time of intervention (T0 vs T6) and to the level of training, reviewed the endotracheal intubation procedure, captured on videotape during the 2 encounters 6 months apart. Evaluation of the participants’ skills in proper handling of laryngoscope, positioning of patient, use of equipment and number of attempts were all relevant criteria.

Statistical analysis

the Statistical Package for Social Sciences (SPSS) version 20 was used for the data management and analyses. Descriptive statistics was carried out by reporting the number and percent for categorical

variables, whereas the mean, median, range and standard deviation were reported for continuous variables. Association between the intervention group and the different variables was assessed using non-parametric tests, mainly, Fishers’s Exact test for categorical variables and the Mann Whitney test for continuous ones. A p-value of ≤0.05 was considered to indicate statistical significance.

Results

The sample consisted of seven participants in their second year of residency and four participants in their third year. Ten out of the eleven participating residents completed the project (Table 1). Theoretical knowledge was assessed at T0 and T6. There was no effect of fidelity on theoretical knowledge. Theoretical knowledge improved with time for both groups, regardless of fidelity. The average number of mistakes (M) varied for both groups: the intervention group showed M (T0) =3.2 and M (T6) =2.6 and the control group showed M (T0) =4.0 and M (T6) =2.4 (Table 2).

There was no significant effect of fidelity on

Fig. 1 Randomization of participants into either high or low fidelity

groups; all participating residents received a lecture and were subjected to a pretest and each group was given the same

sequence in the intervention phase.

M.E.J. ANESTH 22 (5), 2014


Table 1 Basic characteristics of participants in both high and low fidelity groups

Low FidelityN (%)

High FidelityN (%)

P-value

gender male 0 (0.0%) 3 (60.0%)

Female 5 (100.0%) 2 (40.0%) 0.17

age Mean (SD) 26.6 (0.5) 26.8 (0.4) 0.69

med School year 2009 2 (40.0%) 0 (0.0%)

2010 1 (20.0%) 4 (80.0%)

2011 2 (40.0%) 1 (20.0%) 0.13

med_school_location_ Foreign 2 (40.0%) 2 (40.0%)

lebanon 3 (60.0%) 3 (60.0%) 1.00

Formal training yes 1 (20.0%) 1 (20.0%)

no 4 (80.0%) 4 (80.0%) 1.00

Progression_equipment Worse 2 (40.0%) 1 (20.0%)

Same or better 3 (60.0%) 4 (80.0%) 1.00

Progression_positioning Worse 1 (20.0%) 3 (60.0%)

Same or better 4 (80.0%) 2 (40.0%) 0.52

Progression_ambubag Worse 1 (20.0%) 1 (20.0%)

Same or better 4 (80.0%) 4 (80.0%) 1.00

Progression_laryngo Worse 2 (40.0%) 2 (40.0%)

Same or better 3 (60.0%) 3 (60.0%) 1.00

Progression_Technique Worse 1 (20.0%) 1 (20.0%)

Same or better 4 (80.0%) 4 (80.0%) 1.00

Progression_Ett_placement Worse 0 (0.0%) 1 (20.0%)

Same or better 5 (100.0) 4 (80.0%) 1.00

Progression_overall Worse 1 (20.0%) 2 (40.0%)

Same or better 4 (80.0%) 3 (60.0%) 1.00


Table 2Overall Assessment and Logbook Entries in both high and low fidelity groups Pretest and posttest performance, overall assessment,

number of attempts at intubation at T0 and T6, total intubations and total number of successful intubations recorded in logbooks

Low Fidelity High Fidelity P-value

Pretest mistakes mean 4.0 3.2

Median (range) 4.0 (3.0) 3.0 (3.0) 0.42

Sd 1.2 1.3

Posttest mistakes mean 2.4 2.6

Median (range) 2.0 (3.0) 3.0 (4.0) 0.69

Sd 1.1 1.5

Overall Assessment T0 mean 1.6 1.6

Median (range) 1.0 (3.0) 1.0 (2.0) 0.84

Sd 1.3 0.9

Overall Assessment T6 mean 1.4 1.0

Median (range) 1.0 (1.0) 1.0 (0.0) 0.31

Sd 0.5 0.0

attempts t0 mean 1.2 1.0

Median (range) 1.0 (1.0) 1.0 (0.0) 0.69

Sd 0.4 0.0

Attempts T6 mean 1.0 1.6

Median (range) 1.0 (0.0) 2.0 (1.0) 0.15

Sd 0.0 0.4

total intubations recorded in logbook mean 2.6 1.8

Median (range) 1.0 (7.0) 1.0 (5.0) 0.84

Sd 2.9 1.9

Successful intubations in logbook mean 2.0 0.8

Median (range) 1.0 (5.0) 0.0 (3.0) 0.31

Sd 2.0 1.3

M.E.J. ANESTH 22 (5), 2014


Table 3 Evaluation of participants’ performance at T0 in both high and low fidelity groups

Low Fidelity High Fidelity P-valueEquipment Use T0 mean 1.8 1.6

Median (range) 1.0 (3.0) 1.0 (2.0) 1.00Sd 1.3 0.9

Positioning t0 mean 1.4 1.6median range 1.0 (2.0) 2.0 (1.0) 0.55Sd 0.9 0.5

ambubag use t0 mean 1.6 1.4Median (range) 1.0 (3.0) 1.0 (2.0) 1.00Sd 1.3 0.9

laryngoscope handling t0 mean 1.8 1.6Median (range) 1.0 (3.0) 1.0 (2.0) 1.00Sd 1.3 0.9

Intubation Technique T0 mean 1.6 1.4Median (range) 1.0 (3.0) 1.0 (2.0) 1.00Sd 1.3 0.9

ETT Placement Confirmation T0 mean 1.2 1.2Median (range) 1.0 (1.0) 1.0 (1.0) 1.00Sd 0.4 0.4

Table 4 Evaluation of participants’ performance at T6 in both high and low fidelity groups

Low Fidelity High Fidelity P-value

Equipment Use T6 mean 1.6 1.8Median (range) 2.0 (1.0) 2.0 (1.0) 0.69Sd 0.5 0.4

Positioning T6 mean 1.4 1.0Median (range) 1.0 (1.0) 1.0 (0.0) 0.31Sd 0.5 0.0

Ambubag use T6 mean 1.4 1.2

Median (range) 1.0 (1.0) 1.0 (1.0) 0.69

Sd 0.5 0.4

Laryngoscope Handling T6 mean 1.8 1.0Median (range) 2.0 (2.0) 1.0 (0.0) 0.15Sd 0.8 0.0

Intubation Technique T6 mean 1.4 1.0 Median (range) 1.0 (1.0) 1.0 (0.0) 0.31

Sd 0.5 0.0

ETT Placement Confirmation T6 mean 1.2 1.0

Median (range) 1.0 (1.0) 1.0 (0.0) 0.69

Sd 0.4 0.0


practical skills. Equipment use, positioning, ambubag use, laryngoscope handling, intubation technique and ETT placement were not different (p>0.05) when comparing both groups at t(0) (Table 3) or t(6) (Table 3/4).

Successful intubations recorded in the logbook did not vary as a function of fidelity across groups (p=0.31).

DiscussionTheoretical knowledge improved as a function of

time and with recurrent examination for both groups, regardless of exposure to either high or low fidelity. Practical skills did not improve for any group and even regressed in some individual cases. High fidelity simulation had no effect on theoretical or practical skills of residents. This finding shows that practical skills may need more training than theoretical knowledge.

the second aim of the study was to compare the intubation success rate in actual clinical settings of pediatric residents in the intervention group vs. the traditional teaching group during the first 6 months of the intervention. This was assessed with the help of logbooks. the results of successful intubations and the number of intubations in the logbook were not in any way correlated to participant groups. high simulation training did not therefore affect intubation success rate in the actual clinical setting.

the third aim was to contrast the effect of simulation and traditional teaching on retention of knowledge and rate of successful intubation of actual patients 6 months after completion of the intervention. Knowledge retention was indeed found to be solid at T6. Participants made fewer mistakes on the post-test questionnaire than they did on the pre-test. This was found once again regardless of fidelity, and consistent with the first hypothesis. The rate of successful intubations on actual patients after completion of the intervention did not vary as a function of fidelity.

Fidelity had therefore no significant effect on practical skills or theoretical knowledge. This finding can be due to many limitations.

Previous literature found that establishment of mock codes program during residency helped improve residents’ perception in overall skills16. residents who previously fired a defibrillator on a mannequin were more likely to successfully use the defibrillator in a

simulated scenario17 and simulated-based mock codes significantly correlate with improved pediatric patients cardiopulmonary arrest survival rates3. consistent with the literature, practical skills need much practice and training. Even after training, feedback and multiple scenarios across a stretch of 6 months, residents still had difficulty with both the traditional and the high-fidelity training. The literature does emphasize the importance of repetitive training and the inefficiency of PALS alone to solidify knowledge and acquisition of a difficult skill like endotracheal intubation. Even though this study has endorsed more rigorous training than what residents are usually offered, it still fell short in terms of efficient training to improve practical skills. Frequent and repetitive training in intubation is therefore important for skill maintenance over time.Limitations

a major limitation is the small sample size of the residency program. This however allowed for one-on-one training and immediate and direct feedback from the trainer. the attitude of the participants was also an issue. Some participants did not want to be tested despite consenting to the study and the videotaping. a reluctance to properly engage with the study might have affected their performance and their whole disposition towards the study. this might be due to a problem in the methodology regarding the way their performance was recorded for later assessment. the problem was not recorded in studies using similar methods18,19 potentially highlighting cultural issues.

ConclusionIn conclusion, in a small residency program,

high-fidelity and low-fidelity airway training did not affect residents’ intubation technique or actual procedural success when followed over one year. Future studies should involve a higher number of participants, multi-center design, potentially across several specialties where endotracheal intubation is a required competency.

Acknowledgements

the authors would like to thank ms. randa Farha, the simulation lab coordinator, for setting up the mannequins and booking the lab for the study.

M.E.J. ANESTH 22 (5), 2014


References

1. hall Re, PlanT JR, BandS CJ, Wall aR, Kang J and hall Ca: Human patient simulation is effective for teaching paramedic students endotracheal intubation. Acad Emerg Med; 2005, 12:850-855.

2. SChindleR mB, Bohn d, Cox Pn, BRian Wm, JaRviS a, edmondS J and BaRKeR g: outcome of out-of-hospital cardiac or respiratory arrest in children. N Engl J of Med; 1996, 335(20):1473-1479.

3. andReaTTa P, SaxTon e, ThomPSon m and anniCh g: Simulation-based mock codes significantly correlate with improved pediatric patient cardiopulmonary arrest surival rates. Pediatr Crit Care Med; 2011, 12:33-38.

4. SudiKoff Sn, oveRly fl and ShaPiRo mJ: High-fidelity medical simulation as a technique to improve pediatric residents’ emergency airway management and teamwork. Pediatr Emerg Care; 2009, 25:10.

5. oKuda y, BRySon eo, demaRia SJ, JaCoBSon l, QuinoneS J, Shen B and levine ai: the utility of simulation in medical education: what is the evidence? Mt Sinai J Med; 2009, 76(4):330-43.

6. oveRly fl, SudiKoff Sn and ShaPiRo mJ: High-fidelity medical simulation as an assessment tool for pediatric residents’ airway management skills. Pediatr Emerg Care; 2007, 23:11-15.

7. nadel fm, lavelle Jm, fein Ja, giaRdino aP, deCKeR Jm and duRBin dR: teaching resuscitation to pediatric residents: the effects of an intervention. Arch Pediatr Adolesc Med; 2000, 154(10):1049-1054.

8. BoeT S, BoRgeS BC, naiK vn, Siu lW, Riem n, ChandRa d, Bould md and Joo hS: Complex procedural skills are retained for a minimum of 1 yr after a single high-fidelity simulation training session. Br J Anaesth; 2011, 107(4) (Epub ahead of print).

9. WeinBeRg eR, aueRBaCh ma and Shah nB: the use of simulation for pediatric training and assessment. Curr Opin Pediatr; 2009, 21:282-287.

10. lofaSo dP, deBlieux Pm, diCaRlo RP, hilTon C, yang T and Chauvin SW: Design and effectiveness of a required pre-clinical simulation-based curriculum for fundamental clinical skills and procedures. Med Educ Online; 2011, 16:7132. Doi: 10.3402/meo.

v16i0.7132.11. niShiSaKi a, KeRen R and nadKaRni v: Does simulation improve

patient safety?: self-efficacy, competence, operational performance, and patient safety. Anesthesiology Clin; 2007, 25:225-236.

12. mayo Ph, haCKney Je, mueCK T, RiBaudo v and SChneideR Rf: Achieving house staff competence in emergency airway management: results of a teaching program using a computerized patient simulator. Crit Care Med; 2004, 32:2422-2427.

13. Wayne dB, BuTTeR J, Siddall vJ, , linQuiST la, feinglaSS J, Wade ld and mCgaghie WC: Simulation-based training of internal medicine residents in advanced cardiac life support protocols: a randomized trial. Teach Learn Med; 2005, 17(3):210-216.

14. Wayne dB, BuTTeR J, Siddall vJ, fudala mJ, Wade ld, feinglaSS J and mCgaghie WC: Mastery learning of advanced cardiac life support skills by internal medicine residents using simulation technology and deliberate practice. J Gen Intern Med; 2006, 21:251-256.

15. ZuCKeRBeRg a and niCholS d: airway management. in: rogers mc and Helfaer MA (eds). Handbook of Pediatric Intensive Care; 1999; pp. 43-76.

16. Tofil nm, lee WhiTe m, manZella B, mCgill d and ZinKan l: Initiation of a pediatric mock code program at a children’s hospital. Med Teach; 2009, 31(6):e241-247.

17. hunT e, PaTel S, veRa K, ShaffneR dh and PRonovoST PJ: Survey of Pediatric Resident Experiences with Resuscitation Training and attendance at actual cardiopulmonary arrests. Ped Crit Care Med; 2009, 10(1):96-105.

18. finan e, BiSmilla Z, CamPBell C, leBlanC v, JeffeRieS a and WhyTe he: Improved procedural performance following a simulation training session may not be transferable to the clinical environment. J Perinatol Advance Online Publication; 2011, 29 September, doi: 10.1038/jp.2011.141.

19. BRyan R, KReuTeR m and BRoWnSon R: integrating adult learning principles into training for public health practice. Health Promot Pract Advance Online Publication; 2009, 2 April, doi://10.1177/1524839907308117.

487 M.E.J. ANESTH 22 (5), 2014

A Simple protocol to improve SAfety And reduce coSt in HemodiAlySiS pAtientS undergoing

elective Surgery

Johnathan R. Renew* and SheR-Lu Pai*

Abstract

Background: When patients with end-stage renal disease (eSrd) miss their routine intermittent hemodialysis (iHd), electrolyte abnormalities and volume overload often occur. An institutional protocol to ensure that patients receiving iHd have elective surgeries scheduled within 24 hours after their dialysis may reduce procedural delays or cancellations caused by hyperkalemia and hypervolemia after a missed iHd session. the effect of this protocol was evaluated.

Methods: A retrospective chart review was performed for eSrd patients receiving iHd who underwent surgery from 6 months before to 6 months after the institutional protocol was implemented. preoperative potassium values, timing of iHd relative to surgery, and the nature of surgery (elective or emergent) were documented. the percentage of patients having iHd more than 24 hours before their elective surgery was compared before and after protocol implementation. Average potassium values were compared when iHd occurred within 24 hours vs. more than 24 hours, using t test analysis. cost associated with delay and cancellation for iHd was also explored.

Results: of the 15,799 cases performed, 190 involved eSrd patients receiving iHd. Before the protocol, 32.1% of elective cases (n=17) involved patients scheduled for surgery more than 24 hours after iHd vs. 12.0% (n=6) after the protocol. preoperative potassium values were less when patients underwent iHd within 24 hours than at more than 24 hours (mean [Sd], 4.32 [0.6] meq/l vs 4.63 [0.8] meq/l; P=.03).

Conclusions: the simple scheduling policy is effective at reducing both cost and unnecessary perioperative risks for patients.

Keywords: cost effectiveness, elective surgeries, end-stage renal disease, Hemodialysis, Hyperkalemia, Hypervolemia, patient safety.

Abbreviations: eSrd, end-stage renal disease; iHd, intermittent hemodialysis.

* md. Affiliation:DepartmentofAnesthesiology,MayoClinic,Jacksonville,Florida. Corresponding author:Sher-LuPai,MD,DepartmentofAnesthesiology,MayoClinic,4500SanPabloRd,Jacksonville,FL

32224.E-mail:[email protected]

488 REnEw J. R. et. al

Introduction

Since the beginning of 2012, prevalent population included more than 395,000 eSrd patients in the united States requiring intermittent hemodialysis (iHd)1. this patient population presents distinct preoperative considerations. most of these patients have multiple comorbidities, including anemia, cardiovascular disease, and diabetes mellitus. independent of the stress of surgery, this patient population has an adjusted all-cause mortality rate that is 6.5- to 7.9-fold higher than the general population2. merely 52% of hemo dialysis patients are still alive three years after the start of eSrd therapy in 20062.

investigators have found that the overall mortality rate for eSrd patients undergoing general surgery is approximately 4%3. eSrd patients receiving iHd have a 10-fold increase of in-hospital death following spinal surgery4. the need for iHd has been found to be an independent risk factor for postoperative stroke in patients undergoing noncarotid major vascular surgery5. When these patients undergo cardiac surgery, they have higher morbidity rates6, an increased operative mortality rate of 4.8%7, a 30-day mortality rate as high as 18.3%8, and a long-term mortality rate of 29%9. Because of these risks, eSrd patients require effective cooperation and communication between nephrology, anesthesia, and surgical staff.

the role of anesthesiologists expands into perioperative care with the advent of the “surgical home” concept. thus, it is important to gain adequate understanding of medical optimization of patients with eSrd who receive iHd. one particular concern is the management of electrolyte levels, volume status, and the logistical issues relating to perioperative provision of hemodialysis. given their renal dysfunction, patients receiving iHd are at increased risk for preoperative hyperkalemia (serum potassium, >5.5 meq/l), with an incidence as high as 19% to 38%10. volume status is an important issue because patients may require intraoperative transfusion of blood products, necessitating that they be as close to their dry weight as possible to reduce the risk of volume overload.

Because of these issues, the timing of iHd needs to be considered. Although no practice guidelines or recommendations exist for scheduling elective

surgery with respect to iHd, the suggestion has been that iHd should be performed within 24 hours of the operation3,11-13.

At our institution, we have observed instances involving eSrd patients not having iHd within 24 hours of their elective surgeries. Subsequently, the surgical procedures were cancelled or delayed for emergent hemodialysis to correct electrolyte abnormalities and volume overload. to avoid unnecessary cancellation and delays, we implemented an institutional protocol stating that patients receiving iHd would have their elective surgery scheduled within the 24 hours after dialysis. this protocol was shared with medical personnel involved in preoperative care and scheduling (eg, surgeons, physician extenders, preoperative clinic staff).

the purpose of the present study was to establish theefficacyofsuchaschedulingprotocol,toevaluatethe preoperative potassium trends of eSrd patients undergoing surgery, and to explore the cost of cancellation and delays due to not scheduling surgery within 24 hours of a patient undergoing iHd.

Methods

After approved by the mayo clinic institutional review Board, a retrospective chart review was performed for eSrd patients receiving iHd who had surgery from 6 months before to 6 months after the following protocol was implemented and conveyed to personnelinvolvedinpreoperativepatientcare:

1. patients with eSrd who received iHd were identified through the preoperative interviewingprocess and medical record.

2. patients receiving iHd were scheduled to have their elective surgeries less than 24 hours following iHd.

3. preoperative laboratory tests were performed to check serum potassium level on the day of surgery, to ensure proper management of potassium if the reading was greater than 5.0 meq/l.

this scheduling protocol was implemented on november 15, 2011, with data collection ranging from may 15, 2011, to may 15, 2012. patients included were those undergoing surgery both in the main

M.E.J. ANESTH 22 (5), 2014

489A Simple protocol to improve SAfety And reduce coSt in HemodiAlySiS pAtientS undergoing elective Surgery

operating rooms and the outpatient surgery center at our institution. patients undergoing procedures in our interventional radiology, cardiology, and gastroenterology suites were excluded as these patients were not routinely evaluated by the preoperative clinic at our institution. two patients were excluded because it was unclear from the chart review when they last underwent iHd. We documented preoperative potassium values, emergent or elective surgery, and whether the patient received hemodialysis within 24 hours of surgery. furthermore, we investigated the cost of delaying or cancelling elective surgery when a patient did not have iHd within 24 hours of surgery.

to examine the effectiveness of this protocol, we calculated the percentage of elective cases involving eSrd patients undergoing iHd more than 24 hours before surgery both before and after the policy was implemented. in addition, we calculated the percentage of elective cases that had preoperative potassium values checked before and after policy implementation. potassium values were averaged among two subsets of patients-those who had iHd within 24 hours of surgery and those who did not-regardless of whether the case was elective or emergent.

Statistical Analysis

A t test was performed on these potassium averages to determine whether having iHd within 24 hours of surgery produced a statistical difference.

Results

during the study period, a total of 15,799 surgical cases were performed in our operating rooms. of these cases, 190 involved patients with eSrd who were receiving iHd at the time of surgery. these patients comprised the following cases: kidney andliver transplant (n=72), vascular (n=49), orthopedic (n=18), cardiac (n=11), urology and gynecology (n=19), general (n=18), ear, nose, and throat (n=2), and neurosurgery (n=1) procedures. Before the implementation of this protocol, 32.1% of the elective cases (n=17) involved patients being scheduled for surgery more than 24 hours after undergoing iHd, with this figure decreasing to 12.0% (n=6) after the

protocol (table 1).

Table 1 Effect of Policy on Elective Surgery Scheduling

Case Prepolicy Postpolicy

elective cases of patients receiving iHd, no.

53 50

elective cases of patients with iHd >24 h of surgery, no. (%)

17 (32.1) 6 (12.0)

Abbreviation:IHD,intermittenthemodialysis.

one eSrd patient had an elective parathyroidectomy delayed before the protocol was implemented because the patient had a potassium value of 7.3 meq/l. this patient was receiving iHd on a monday-Wednesday-friday schedule and presented for surgery as the first case on aMonday morning,having gone nearly 72 hours without iHd.

Another eSrd patient had an elective arteriovenous fistula formation cancelled because ofhyperkalemia after the policy was implemented, with a potassium value of 5.7 meq/l despite having iHd the day before surgery. in reviewing this patient’s chart, we learned that the patient consumed a meal high in potassium the night before surgery after undergoing iHd earlier that day.

potassium values drawn the day of either elective or emergent surgery were analyzed. for patients who had iHd within 24 hours, the mean (Sd) potassium value was 4.32 (0.6) meq/l. of patients undergoing surgery more than 24 hours after iHd, the mean (Sd) potassium value was 4.63 (0.8) meq/l. After t test analysis, these two average potassium values were found to be statistically different (P=.03). in addition to requiring that eSrd patients have their elective surgery scheduled within 24 hours of iHd, the protocol also conveyed the need to check potassium values on the day of surgery. the effect of policy on preoperative laboratory tests was evaluated (table 2).

Additional expenses associated with delaying elective cases for emergent preoperative hemodialysis included the costs of dialysis, extra perioperative personnelstaffingtimefromthedelay,resterilizationofthe instruments from the surgery suite, stat laboratory tests after dialysis, and lost income from having an unused operating room.


Discussion

this retrospective study examined the implementation of a protocol requiring patients with eSrd to have iHd within 24 hours of elective surgery and to have their preoperative potassium values obtained before surgery. this policy was conveyed through e-mail correspondence and educational conferences to personnel involved in preoperative care of surgical patients. indeed, this protocol was effective at decreasing the percentage of eSrd patients having elective surgery more than 24 hours after iHd. Although no universal practice guidelines specify the timing of elective surgery for patients receiving iHd, several studies have recommended that iHd be done within 24 hours of surgery3,11-13. these strategies are targeted toward avoiding unnecessary perioperative risks, such as hyperkalemia and hypervolemia.

Hyperkalemia can induce deadly cardiac arrhythmias and alter the anesthetic plan. for instance, succinylcholine therapy may have to be avoided for a patient with a difficult airway if thepatient has preoperative hyperkalemia. thus, it has been recommended that the serum potassium concentration be less than 5.5 meq/l for elective surgery14. fortunately, the use of succinylcholine in normokalemic patients with eSrd has been shown to be safe because it increases serum potassium values to the same degree as in patients without eSrd15.

the protocol failed at encouraging perioperative staff to check potassium values on the day of surgery. of patients with eSrd undergoing either elective or emergent surgery, 85.3% had preoperative potassium

values checked before the protocol’s implementation vs 73.7% after it. interestingly, in two instances-1 preprotocol and 1 postprotocol-patients with eSrd underwent emergent surgery without first checkingserum potassium values. from reviewing the charts, we presumed that these patients had iHd within 24 hours of the emergent case and the anesthesiologist felt comfortable proceeding without this information. We caution against such practices and suggest the routine checking of preoperative potassium level, regardless of when iHd was last performed. eight patients in this study had iHd within 24 hours yet still had potassium values of 5.5 meq/l or greater. requiring that patients have iHd within 24 hours will not eliminate the incidence of preoperative hyperkalemia; average potassium values were statistically lower when patients had iHd within 24 hours than when patients did not.

investigators have recommended that hemodialysis patients be as close to dry weight as possible preoperatively16. Hypervolemia is a particular concern in this population because patients often have anemia from eSrd. Because of lower hemoglobin content, they may require intraoperative blood products more often than patients without eSrd who have hemoglobin levels within the normal limits. transfusion of blood products has its own risk factors, including an increased potassium burden. in addition, when patients not at dry weight preoperatively receive a transfusion, they may be at risk for acute congestive heart failure. furthermore, when these patients have an unanticipated surgical bleeding that necessitates massive volume replacement, the use of intraoperative dialysis may be warranted-an expensive endeavor that

Table 2 Effect of Policy on Checking Preoperative Potassium Values

Case Characteristics Prepolicy Postpolicy

cases with patients receiving iHd, no. 95 95

patients with potassium values checked preop, no. (%) 81 (85.3) 70 (73.7)

emergent cases with patients receiving iHd, no. 42 45

emergent cases with patient potassium values checked preop, no. (%) 41 (97.6) 44 (97.8)

elective cases with patients receiving iHd, no. 53 50

elective cases with patient potassium values checked preop, no. (%) 40 (75.5) 26 (52.0)Abbreviations:IHD,intermittenthemodialysis;preop,preoperation.

M.E.J. ANESTH 22 (5), 2014

491A Simple protocol to improve SAfety And reduce coSt in HemodiAlySiS pAtientS undergoing elective Surgery

may have been avoided if volume status was optimized before surgery. the potential for these risks can be reduced by ensuring that patients have iHd within 24 hours of an elective surgical procedure.

in addition to improving patient safety, our scheduling protocol can have a marked cost-saving benefit.Although the savings is difficult to quantify,there is undeniable increased expense when surgical procedures are delayed or canceled.

A question remains about whether iHd on the day before surgery is safer for patients than iHd on the same day of and immediately preceding surgery. Heparin use during iHd suggests that iHd should be done 12 hours before surgery. However, to reduce the effects on coagulation, most centers now can perform heparin-free iHd10.

Having iHd on the same day of surgery may place the patient at risk for dialysis disequilibrium syndrome. the rate of urea removal during iHd is a crucial factor in the development of this syndrome, and patientsmayundergodialysisatincreasedbloodflowrates the day of surgery, in an effort not to delay their upcoming procedure.17. this practice may be avoided by having iHd on the day before elective surgery.

yukioka et al18 investigated the effects of iHd administered at 24 hours vs 3 hours before surgery. Serum potassium values were similar for the 2 groups preoperatively; however, the patients with iHd at 3 hours before surgery were more likely to have intraoperative hyperkalemia. the investigators attributed this outcome to the removal of less fluidduring the iHd of these patients.

A potential criticism of the present study is the

small sample size when looking at scheduling trends involving 6 months before and 6 months after the protocol implementation. expanding the study period may show that more providers are not adhering to the recommendations, necessitating the need for repeat educational efforts to ensure the hemodialysis patients have their elective surgeries scheduled according to the protocol. noting the volume status of these patients while potassium values were recorded would have been interesting. unfortunately, dry weight was rarely noted and was not easily accessible during the present chart review. in addition, a connection was not made between having surgery more than 24 hours after iHd and clinical outcomes such as death and major morbidity.

Heldt et al19 described eSrd patients who had similar clinical outcomes (eg, blood loss, complication rate, postoperative stay, and positive margins) as patients not on dialysis when iHd was performed the day before radical prostatectomy. likewise, gulati et al20 reported that patients with eSrd receiving iHd had similar blood loss and median time to discharge as patients who had normal renal function while undergoing laparoscopic radical nephrectomy when the patients were kept on their normal iHd routine, including iHd on the day before surgery. future efforts warrant further exploration to see whether such a scheduling protocol has impact on patient outcomes.

in conclusion, the implementation of a scheduling policy for eSrd that states that iHd should be done within 24 hours before elective surgery is simple to conduct, may reduce cost, and does reduce potential unnecessary risks for patients.


References

1. U.S.RenalDataSystem,USRDS2013AnnualDataReport:Atlasofchronic Kidney disease and end-Stage renal disease in the united States, national institutes of Health, national institute of diabetes and digestive and Kidney diseases, Bethesda, md, 2013. 2013. volume2,chapter1.http://www.usrds.org/2013/pdf/v2_ch1_13.pdf.

2. U.S.RenalDataSystem,USRDS2013AnnualDataReport:Atlasofchronic Kidney disease and end-Stage renal disease in the united States, national institutes of Health, national institute of diabetes and digestive and Kidney diseases, Bethesda, md, 2013.. volume 2,chapter5.http://www.usrds.org/2013/pdf/v2_ch5_13.pdf.

3. KeLLeRman PS:Perioperativecareoftherenalpatient.Arch Intern Med;1994Aug8;154(15):1674-88.

4. chikuda H, yaSunaga H, HoRiguchi H, takeShita K, Kawaguchi H, matSuda S, nakamuRa K:Mortalityandmorbidity indialysis-dependentpatientsundergoingspinalsurgery:analysisofanationaladministrativedatabaseinJapan.J Bone Joint Surg Am; 2012 mar 7;94(5):433-8.

5. ShaRifPouR m, mooRe le, ShankeS Am, didieR TJ,KheteRPaL S, maShouR GA:Incidence,predictors,andoutcomesofperioperativestroke in noncarotid major vascular surgery. Anesth Analg; 2013 Feb;116(2):424-34.

6. deutSch e, BeRnStein rc, Addonizio p, KuSSmauL Wg 3rd:Coronaryarterybypasssurgeryinpatientsonchronichemodialysis:a case-control study. Ann Intern Med;1989Mar1;110(5):369-72. Erratum in: Ann Intern Med;1989May1;110(9):752.

7. yamauchi t, miyata h, Sakaguchi t, miyagawa S, yoShikawa y, takeda k, motomuRa n, tSukihaRa h, Sawa y: coronary artery bypass grafting in hemodialysis-dependent patients: analysisof Japan Adult Cardiovascular Surgery Database. Circ J; 2012; 76(5):1115-20.

8. kogan a, medaLion B, koRnowSki R, Raanani e, ShaRoni e, StamLeR a, SahaR g, SniR e, PoRat e: cardiac surgery in patients on chronic hemodialysis: short and long-term survival. Thorac Cardiovasc Surg;2008Apr;56(3):123-7.

9. dhanani J, muLLany dV, fRaSeR Jf: effect of preoperative renal

function on long-term survival after cardiac surgery. J Thorac Cardiovasc Surg;2013Jul;146(1):90-5.

10. KRiShnan m. preoperative care of patients with kidney disease. Am FamPhysician.2002Oct15;66(8):1471-6,1379.

11. Hata m, remmeRS AR JR, lindLey JD, SaRLeS He, fiSh JC:Surgical management of the dialysis patient. Ann Surg; 1973 Aug; 178(2):134-7.

12. HaimoV m, gLaBman S, SchuPak e, neff m, BuRRowS L:Generalsurgery in patients on maintenance hemodialysis. Ann Surg; 1974 Jun;179(6):863-7.

13. tRainoR d, BoRthwick e, feRguSon a:Perioperativemanagementof the hemodialysis patient. Semin Dial;2011May-Jun;24(3):314-26.

14. HineS rl, maRSchaLL K:. Stoelting’s anesthesia and co-existingdisease. 5th ed. Philadelphia (PA):ChurchillLivingstone/Elsevier;c2008. 676 p.

15. thaPa S, BRuLL SJ: Succinylcholine-induced hyperkalemia inpatientswithrenalfailure:anoldquestionrevisited.Anesth Analg; 2000Jul;91(1):237-41.

16. cRaig rg, HunteR JM:Recentdevelopments in theperioperativemanagement of adult patients with chronic kidney disease. Br J Anaesth;2008Sep;101(3):296-310.

17. ZePeda-oRozco d, QuigLey R:Dialysis disequilibrium syndrome.Pediatr Nephrol;2012Dec;27(12):2205-11.

18. yukioka h, kuRita S, fuJimoRi m: [Perioperative managementof patients on maintenance hemodialysis: serum potassium andhemodynamic changes during anesthesia]. Masui; 1992 Jan;41(1):33-6.Japanese.

19. HeLdt JP,JeLLiSon fc, yuen Wd, tenggaRdJaJa cf, lui pd, ruckLe Hc, BaRkeR gr, BaLdwin DD:Patientswithend-stagerenaldiseaseare candidates for robot-assisted laparoscopic radical prostatectomy. J Endourol;2011Jul;25(7):1175-80.

20. guLati m, meng mv, fReiSe ce, StoLLeR ML: Laparoscopicradical nephrectomy for suspected renal cell carcinoma in dialysis-dependent patients. Urology;2003Sep;62(3):430-6.

493 M.E.J. ANESTH 22 (5), 2014

EmEtogEnicity-Risk PRocEduREs in samE day suRgERy cEntER of an acadEmic univERsity HosPital

in unitEd statEs: a REtRosPEctivE cost-audit of PostoPERativE nausEa vomiting managEmEnt

Deepak Gupta* anD Halim Haber*

Abstract

Background: despite the variable results of published studies, it is imperative for ambulatory surgery centers to self-audit local cost-implications for post-operative nausea and vomiting (Ponv) management.

Objective: our retrospective cost-audit assessed if there were comparative peri-anesthesia care cost-trends among patients who had undergone low-Emetogenicity-Risk Procedures (lERP), moderate-Emetogenicity-Risk Procedures (mERP) and severe-Emetogenicity-Risk Procedures (sERP).

Methods: this study was a review of same day surgery center practices in an academic university hospital setting during a three-year period (2010-2012). the patient lists were accessed from cis and citRiX app Bar for time audit and oR (operating room) schedule reports. subsequently, oR pharmacy department ran a search for peri-operative anti-emetics and opioids that were billed for the patients at same day surgery center for the review period. the primary outcomes were the comparative costs/charges of these medications and comparative durations/charges for these patients’ stay in the post-anesthesia care unit (Pacu). secondary outcomes analyzed in the study included peri-anesthesia durations.

Results: a total of 8,657 patient records were analyzed. almost all analyzed variables revealed statistically significant inter-variable positive correlations. The patients’ age was significantly (P <0.001) different among lERP/mERP/sERP patients (lERP: 48.8 ± 14.7 years; mERP: 61.8 ± 14.6 years; sERP: 51.3 ± 14.5 years). in regards to primary and secondary outcomes, the statistical significant differences among LERP/MERP/SERP patients (after correcting for both patients’ age as well as patients’ sex) were only achieved for preoperative times (P = 0.002; Power = 0.9), operating room recovery times (P = 0.003; Power = 0.9), Pacu stay times (P <0.001; Power = 1.0), and Pacu charges (P <0.001; Power = 1.0).

Conclusion: PACU stay times and PACU charges were significantly higher in patients who had undergone sERP as compared to patients who had undergone lERP or mERP at our same day surgery center.

* md. Affiliation: Department of Anesthesiology, Wayne State University, Detroit, Michigan, United States. Corresponding author: Halim Haber, MD. Clinical Associate Professor, Anesthesiology, Wayne State University/Detroit

medical center, Box no 162, 3990 John R, detroit, mi 48201, united states, tel: 1-313-745-7233, fax: 1-313-993-3889. E-mail: [email protected]

494 guPta d. et. al

Introduction

Prevention of postoperative nausea and vomiting (Ponv) is a highly prioritized expectation among the patients who present for same day surgeries at ambulatory surgery centers1-3. Breast surgeries and strabismus surgeries are highly emetogenic surgical procedures4 and are being increasingly performed as same day surgeries. therefore, Ponv management (including pre-emptive anti-emesis) is a warranted tool in the arsenal of anesthesia care personnel who practice anesthesia at ambulatory surgery centers. there have been studies5-7 investigating cost-related efficacies for various anti-emetics regimens. despite the variable results of published studies, it is imperative for ambulatory surgery centers to self-audit their institutional performance to both increase Ponv prevention rates and improve their patients’ Ponv treatments. this self-auditing should also place particular emphasis on periodic assessment of local cost-implications for Ponv management.

in this study, our retrospective cost-audit assessed if there were comparative peri-anesthesia care cost-trends among patients who had undergone low-Emetogenicity-Risk Procedures (lERP), moderate-Emetogenicity-Risk Procedures (mERP) and severe-Emetogenicity-Risk Procedures (sERP). this study was a review of same day surgery center practices in an academic university hospital setting.

Methods

after institutional review board approval for retrospective audit with waived consent, medical records for patients aged 18 years and above who presented to same day surgery center for their surgeries during a three-year period (2010-2012), were reviewed. the patient lists were accessed from cis and citRiX app Bar for time audit and oR (operating room) schedule reports. subsequently, oR pharmacy department ran a search for the common anti-emetics that were billed for the patients at same day surgery center for the review period. the reported anti-emetics included ondansetron, metoclopramide, dexamethasone, diphenhydramine, scopolamine, promethazine, prochlorperazine and droperidol.

simultaneous reports were also run for peri-operative opioids as a potential confounding factor for Ponv. the primary outcomes were the comparative costs/charges of these medications and comparative durations/charges for these patients’ stay in the post-anesthesia care unit (Pacu). Patients’ surgical procedures were post-hoc-categorized as lERP, mERP and sERP (appendix a). secondary outcomes analyzed in the study included peri-anesthesia durations, such as pre-operative times (in the pre-operative holding area), pre-incision times (operating room entry to surgical incision), surgery times (skin incision to skin closure) and operating room recovery times (skin closure to operating room exit).

for statistical analysis, correlations between continuous variables were analyzed using Pearson correlation coefficients. Comparisons of continuous variables were analyzed using appropriate anova tests. categorical proportions were analyzed using the Chi Square test (Fisher Exact Tests). The final analysis for significance among LERP/MERP/SERP patients was performed based on corrections for confounding factors namely patients› age as a covariate, and patients› sex as independent variable for the compared outcomes/variables. P values of <0.05 were considered as statistically significant.

Results

as shown in consoRt diagram (fig. 1), a total of 8,657 patient records were analyzed. from these patients (n = 8657), almost all of the ten analyzed variables (Table 1) revealed statistically significant inter-variable positive correlations. the only non-significant correlations were charges for parenteral opioids, oral opioids and combined drugs not correlating with pre-operative times; and charges for oral opioids and parenteral anti-emetics not correlating with charges for parenteral opioids. the correlation coefficient for PACU stay times and PACU charges was almost 1 (= +0.99) as Pacu charges were directly calculated from Pacu stay times as per 219 usd for first 30 minutes and 179 USD for each additional 30 minutes. Similarly the correlation coefficient for parenteral opioids charges and combined drugs charges (sums of charges for parenteral opioids, oral opioids

M.E.J. ANESTH 22 (5), 2014

495EmEtogEnicity-Risk PRocEduREs in samE day suRgERy cEntER of an acadEmic univERsity HosPital in unitEd statEs: a REtRosPEctivE cost-audit of PostoPERativE nausEa vomiting managEmEnt

Appendix A Lists of Same Day Surgery Center's surgical procedures that have been post-hoc-categorized according

to their emetogenic potential

Low-Emetogenicity-Risk Procedures

(LERP)

Moderate-Emetogenicity-Risk

Procedures (MERP)

Severe-Emetogenicity-Risk Procedures

(SERP)

amputation finger(s) abdominoplasty Biopsy Breast

amputation Hand Biopsy conjuctiva Biopsy Breast Excisional

arthrodesis carpal/metacarpal Biopsy lacrimal gland Biopsy Breast w/needle localization

arthroplasty metacarpal Biopsy lEEP capsulectomy Breast

arthroplasty thumb Biopsy testes cholecystectomy laparoscopic

Biopsy Chest Wall Bleb needling Excision Breast mass

Biopsy lymph node Blepharoplasty (oPH) Excision Breast mass Bilateral

Biopsy lymph node axillary Blepharoplasty (Pla) Excision Breast Wide w/Sentinal Node Bx

Biopsy temporal artery cannulation tear duct Eye muscle surgery

Block celiac Plexus chelation Band keratopathy insert Breast Expander

Block celiac Plexus neurolytic w/

alcohol

cryosurgery Eye insertion skin/tissue Expander

Block celiac Plexus Radiofrequency cutler Beard Eye stage 2 ligation tubal laparoscopic

Block Epidural d&c lumpectomy Breast

Block Epidural caudal d&c Hysteroscopy mammoplasty augmentation

Block facet d&c suction mammoplasty Reduction

Block ganglion dacryocystorhinostomy (oPH) mastectomy

Block nerve dacryocystorhinostomy Endo (oPH) mastectomy Bilateral

Block nerve facet dacryocystorhinostomy External

(oPH)

Mastectomy Modified Radical

Block nerve selective decompression orbit mastectomy Partial

Block superior Hypogastric neurolytic dilation Probe irrigate tear duct mastectomy Radical

Block sympathetic lumbar drainage choroidal Effusion mastopexy

Block/injection Joint lumbar facet dsEk Recession-Resection Eye muscle

Bronchoscopy w/EBus Enucleation Reconstruct Breast

Bunionectomy Evisceration Eye Reconstruct Breast w/Expander

capsulotomy Exam under anesthesia Eye Reconstruct nipple areolar

closed Reduction finger Excision abdominal mass Repair Eye muscle laceration

closed Reduction finger Excision abdominal mass Repair Eye muscle laceration

closed Reduction finger Perc Pinning Excision chalazion Revision Breast scar

closed Reduction Hand Excision facial/Head mass

closed Reduction metacarpal Perc

Pinning

Excision orbital dermoid

Closed Reduction Wrist Perc Pinning Excision Pterygium

cystectomy Pilonidal Excision w/Biopsy neck mass/lesion

debridement decubitus ulcer Extcap cataract Extract w/iol implant

dissection axillary node Extcap cataract Extract w/iol implant

and trabeculectomy

496


(LERP)


Procedures (MERP)


(SERP)

dissection lymph node flap latissimus

Exam under anesthesia Rectal/anal flap Rotation

Excision axillary mass flap tram

Excision Back mass ganciclovir implant

Excision Bone cyst graft dermal orbit

Excision Buttock mass graft skin full thickness (Pla)

Excision ganglion cyst graft skin split thickness (Pla)

Excision ganglion cyst (oRt) Herniorrhaphy umbilical

Excision groin mass Herniorrhaphy ventral

Excision Hidradenitis Hydrocelectomy

Excision Hip mass Hysteroscopy

Excision keloid injection silicone oil

Excision lesion insert orbital implant

Excision limb mass insertion ahmed valve

Excision mass upper limb insertion crawford tube

Excision Rectal/anal mass insertion implant lens secondary

Excision scar insertion molteno implant

Excision shoulder mass insertion Radioactive Plaques

Exostectomy insertion Retisert implant

fistulectomy anal insertion valve w/scleral graft

fistulectomy anal insertion valve w/scleral graft

flap cross finger iridectomy

Fulguration Wart(s) laser Photocoagulation

Fusion Hand/Wrist lensectomy/vitrectomy

graft Bone ligation spermatic vein

Harvest Bone marrow lipectomy

Hemorrhoidectomy liposuction

Herniorrhaphy liposuction abdomen

Herniorrhaphy inguinal marsupilization Bartholin cyst

incision & drainage orbitotomy

incision and drainage orchiectomy

injection caudal Epidural Phacoemulsification Cataract Implant

insert cath Epidural tunneled titanium Photocoagulation Pan Retinal

insert catheter Epidural Reconstruct canthus

insert catheter Hemodialysis Reconstruct Ear

insert catheter/Port Reconstruct Eyelid

insert Pump Pain Reconstruction orbital w/graft

irrigate & debride (oRt) Remove corneal sutures

oRif Hand Remove frgn Body intraocular

oRif metacarpal/carpal Remove frgn Body orbit

guPta d. et. al

M.E.J. ANESTH 22 (5), 2014

497


(LERP)


Procedures (MERP)


(SERP)

oRif thumb Remove Radioactive Plaques

ORIF Wrist Remove silicone oil

Release carpal tunnel (oRt) Repair anterior

Release trigger thumb/finger Repair canalicular laceration

Removal foreign Body Repair corneal laceration

Remove catheter/Port Repair Dehiscence Eye Wound

Remove K-Wire Repair Ectropion

Repair artery Radial Repair Entropion

Repair laceration tendon/artery/nerve

(Pla)

Repair laceration lid (Pla)

Repair mallet finger Repair orbital fracture

Repair mallet finger Repair orbital fracture

Revision amputation finger(s) Repair Ptosis

tenolysis Repair Retinal detachment

transposition ulnar nerve Repair Ruptured globe

Reposition lens

Revision ahmed valve

Revision Bleb

scleral Buckle

septorhinoplasty

shunt Express Eye

tap anterior chamber

tarsorrhaphy

thyroidectomy (gEn)

trabeculectomy

transplant cornea

vasectomy (surgical)

vasovasostomy

vitrectomy

vitrectomy anterior

vitrectomy Pars Plana 20 ga w/scleral

Buckle

vitrectomy Pars Plana 20 gauge


Buckle

vitrectomy Pars Plana 23 gauge

vitrectomy Pars Plana 25 ga


Buckle

Vitreous Washout

EmEtogEnicity-Risk PRocEduREs in samE day suRgERy cEntER of an acadEmic univERsity HosPital in unitEd statEs: a REtRosPEctivE cost-audit of PostoPERativE nausEa vomiting managEmEnt

498 guPta d. et. al

and parenteral anti-emetics) was almost 1 (= +0.98) as oral opioids charges and parenteral anti-emetics charges nullified each other’s effects on correlations by having opposite regression directions (-0.01 and +0.01 respectively). Even though medications databases indicated that 60% medications were administered by anesthesia providers (as indicated by manual charge) and 40% medications were administered by Pacu nursing staff (as indicated by charge on administration), the administered medications could not be categorized whether they were given as prophylaxis or as rescue dosing for analgesia and/or anti-emesis. one interesting observation was that the patients’ medication charges were multiples of x-times factor to hospital’s medication costs [median x: 10 (Range x: 9-124); mode x: 10; mean x (± sd): 18 (± 22)].

Fig. 1 CONSORT Diagram

after categorizing the patient records among lERP, mERP and sERP based on the emetogenicity of the surgical procedures, the patients’ age was significantly (P <0.001) different among these three groups (lERP: 48.8 ± 14.7 years; mERP: 61.8 ± 14.6

years; sERP: 51.3 ± 14.5 years). therefore, when anova analysis was performed for the variables with patients’ sex and emetogenic risk category of surgical procedures as two independent factors, patients’ age was required to be analyzed as a covariate for this anova analysis. Hence, even though the means table for this analysis of variables (table 2) appear to have clinically significant differences, the statistical significant differences among LERP, MERP and sERP categories (after correcting for both patients’ age as well as patients’ sex) were only achieved for preoperative times (P = 0.002; Power = 0.9), operating room recovery times (P = 0.003; Power = 0.9), Pacu stay times (P <0.001; Power = 1.0), and Pacu charges (P <0.001; Power = 1.0). among lERP/mERP/sERP patients, one reason for the absence of statistical significance for other variables (preincision times, surgery times, parenteral opioid charges, oral opioid charges, parenteral anti-emetic charges and combined drugs charges) was low statistical power (1-beta) for those variables (Power <0.6; after patients’ age and patients’ sex correction).

Discussion

in the society for ambulatory anesthesia Ponv guidelines (2007)8, ten procedures were documented as risk factors for Ponv in adults. for our center’s retrospective cost-audit, we sub-categorized the first four procedures (laparoscopy, laparotomy, breast and strabismus) as sERP and the remaining six procedures (plastic, maxillofacial, gynecological, abdominal, neurologic, ophthalmologic and urologic) as mERP. although society for ambulatory anesthesia Ponv guidelines (2014)9 updated only cholecystectomy, gynecological and laparoscopic surgeries (compared to general surgeries) as emetogenic-risk procedures, we based our retrospective cost-audit on 2007 Ponv guidelines that were current standard practices for the studied three-year period (2010-2012).

as far as patients’ medication charges being multiples of x-times factor to hospital’s medication costs, these were based on local pharmacy charge masters10 that take into account complex and varied interactions of medications’ prices (in wholesale markets), categories and routes of administrations,

M.E.J. ANESTH 22 (5), 2014


Table 1 (a) Pearson correlation coefficients among the recorded variables

n = 8657 Pre-Operative Time

Pre-Incision Time

Surgery Time Operating Room

Recovery Time

Post Anesthesia Care Unit Stay

Time

Pre-Operative Time not applicable 0.07** 0.09** 0.1** 0.13**

Pre-Incision Time 0.07** not applicable

0.54** 0.4** 0.39**

Surgery Time 0.09** 0.54** not applicable

0.37** 0.4**

Operating Room Recovery Time 0.1** 0.4** 0.37** not applicable 0.44**

Post Anesthesia Care Unit Stay Time

0.13** 0.39** 0.4** 0.44** not applicable

Post Anesthesia Care UnitCharges

0.13** 0.38** 0.39** 0.44** 0.99**

Parenteral Opioid Charges 0.01 0.16** 0.16** 0.1** 0.19**

Oral Opioid Charges 0.02 0.04** 0.03* 0.09** 0.12**

Parenteral Anti-Emetic Charges 0.04** 0.25** 0.33** 0.3** 0.21**

Combined Drugs Charges 0.02 0.21** 0.22** 0.15** 0.23**

**: Correlation is significant <0.01 (2-tailed)*: Correlation is significant <0.05 (2-tailed)

Table 1 (b) Pearson correlation coefficients among the recorded variables

n = 8657 Post Anesthesia Care Unit Charges

Parenteral Opioid Charges

Oral Opioid Charges

Parenteral Anti-Emetic

Charges

Combined Drugs Charges

Pre-Operative Time 0.13** 0.01 0.02 0.04** 0.02

Pre-Incision Time 0.38** 0.16** 0.04** 0.25** 0.21**

Surgery Time 0.39** 0.16** 0.03* 0.33** 0.22**

Operating Room Recovery Time

0.44** 0.1** 0.09** 0.3** 0.15**

Post Anesthesia Care Unit Stay Time

0.99** 0.19** 0.12** 0.21** 0.23**

Post Anesthesia Care Unit Charges

not applicable 0.18** 0.12** 0.2** 0.22**

Parenteral Opioid Charges 0.18** not applicable -0.01 0.01 0.98**

Oral Opioid Charges 0.12** -0.01 not applicable 0.03* 0.04**

Parenteral Anti-Emetic Charges

0.2** 0.01 0.03* not applicable 0.2**

Combined Drugs Charges 0.22** 0.98** 0.04** 0.2** not applicable**: Correlation is significant <0.01 (2-tailed)

*: Correlation is significant <0.05 (2-tailed)

500 guPta d. et. al

and pharmacists’ involvements in dispensing the charged medications. additionally, there is a standard sophisticated mark-up tables that also account for any overhead costs involved.

from published reports, we reviewed two studies analyzing PONV costs. The first one was a retrospective database study (n = 3641) by Habib et al.11 and the second one was a prospective study (n = 100) by Parra-sanchez et al.12 Habib et al.11 reported prophylactic anti-emetics administration in 79% patients and rescue anti-emetics administration in 26% patients. comparatively, in our study, 40% lERP patients, 41% mERP patients and 50% sERP patients

(42% overall patients; n = 8657) had received at least one parenteral anti-emetic agent during peri-anesthesia period (P <0.001); however, proportions of patients who had received at least one parenteral opioid during peri-anesthesia period were not significantly different (88% lERP patients, 89% mERP patients and 90% sERP patients; P = 0.17).

Parra-sanchez et al.12 reported significant PACU recovery costs differences (640 usd vs. 730 usd; P = 0.006) between patients without Ponv vs. patients reporting Ponv respectively. comparatively, in our study, mean Pacu charges were 720-743 usd for lERP patients, 525-546 usd for mERP patients

Table 2 Various recorded variables for comparative analysis among three types of ambulatory surgeries based on their emetogenic potential

Recorded variable Low-Emetogenicity-Risk Procedures (LERP)

Moderate-Emetogenicity-Risk Procedures (MERP)

Severe-Emetogenicity-Risk Procedures (SERP)

Females(n = 895)

Males(n = 548)

Females(n = 3310)

Males(n = 2502)

Females(n = 1288)

Males(n = 114)

Pre-operative time (mins)

109.0 ± 52.7 105.8 ± 45.6 113.2 ± 48.2 113.9 ± 53.3 164.3 ± 96.1 114.4 ± 54.7

Pre-incision time (mins)

20.9 ± 9.8 21.0 ± 8.6 19.2 ± 7.2 20.8 ± 8.2 28.3 ± 9.4 21.5 ± 7.0

surgery time (mins) 40.2 ± 35.3 42.8 ± 32.3 42.4 ± 43.7 58.7 ± 59.4 101.3 ± 69.7 47.3 ± 33.0

operating Room Recovery time (mins)

5.3 ± 4.3 5.6 ± 4.5 3.9 ± 4.3 5.0 ± 5.6 9.4 ± 5.5 11.9 ± 5.8

Post-anesthesia care unit stay time (mins)

99.6 ± 55.5 103.6 ± 61.8 66.0 ± 38.7 69.8 ± 39.6 135.5 ± 53.5 106.5 ± 44.5

Post-anesthesia care unit charges (usd)

720.4 ± 336.6 742.9 ± 370.3 524.9 ± 232.4 545.5 ± 238.3 934.9 ± 323.7 770.1 ± 275.8

Parenteral opioids charges (usd)

23.3 ± 102.2 27.1 ± 98.3 9.2 ± 13.8 10.2 ± 18.4 26.3 ± 29.9 16.8 ± 19.6

oral opioids charges (usd)

0.8 ± 2.1 0.9 ± 2.3 0.6 ± 1.8 0.6 ± 1.8 1.0 ± 2.4 1.8 ± 4.0

Parenteral anti-Emetics charges (usd)

4.8 ± 8.0 4.1 ± 6.8 4.8 ± 8.2 6.6 ± 9.1 6.5 ± 9.4 9.5 ± 7.5

combined drugs charges (usd)

28.9 ± 102.1 32.2 ± 98.3 14.6 ± 16.8 17.4 ± 21.5 33.8 ± 31.5 28.1 ± 19.7

M.E.J. ANESTH 22 (5), 2014


and 770-935 usd for sERP patients (P <0.001). an interesting observation (table 2) was that patients who had undergone lERP stayed longer in Pacu as compared to patients who had undergone mERP even though the parenteral anti-emetics charges did not follow a similar trend between lERP patients and mERP patients. However, parenteral opioid charges followed a similar trend (lERP patients’ charges >>mERP patients’ charges). thereafter, a sub-analysis using both parenteral opioid charges and patients’ age as covariates reduced statistical significance for PACU stay times (P = 0.02; Power = 0.7) and Pacu charges (P = 0.007; Power = 0.8). this loss in statistical significance suggested that pain management acted as an independent confounding factor for prolonged Pacu stay in patients who had undergone lERP as compared to patients who had undergone mERP. to assess surgery times effect on Pacu stay times and Pacu charges across lERP/mERP/sERP, a further sub-analysis was performed with surgery time as an additional covariate besides parenteral opioid charges and patients’ age as other covariates. using these three covariates removed all statistical significance level for both Pacu stay times (P >0.99; Power = 0.05) and Pacu charges (P = 0.96; Power = 0.06) suggesting that surgery times (besides patients’ age and parenteral opioid charges) were an independent factor that confounded the differences in Pacu stay times and Pacu charges across lERP/mERP/sERP.

our study has a few limitations. it was a retrospective study that only explored the anesthesia-based billed surgical procedures’ database and pharmacy-based billed peri-anesthesia medications’ database. therefore, in our study, other data like preoperative risk factors for Ponv, peri-operative pain scores vs. peri-operative emesis scores, intraoperative

medication administration timings vs. postoperative medication administration timings, and prophylactic medications vs. rescue medications were not available to be evaluated/compared. our analysis was primarily based on categorizing the billed charges data according to the emetogenicity-risk procedures and absence of the above-mentioned potentially confounding variables may have skewed our results (means, level of significance and correlation coefficients).

Conclusion

in summary, Pacu stay times and Pacu charges were significantly higher in patients who had undergone sERP as compared to patients who had undergone lERP or mERP at our same day surgery center.

Acknowledgement

the authors are deeply indebted to the appreciative efforts of ms Janice dale, data analyst, department of anesthesiology, and ms. connie tourangeau, Pharmacist, and mr. Xavier Bell, field Engineer, department of Pharmacy, Harper Hospital, detroit medical center, detroit, michigan, united states in regards to their retrospective enlisting of the same day surgery patients according to their surgical procedures as well as according to the medications that they had received per their databases. the authors are also grateful to dr Ronald thomas, children’s Research Center of Michigan, Wayne State University, Detroit, michigan and george mckelvey, Phd, department of anesthesiology, Harper Hospital, detroit medical center, detroit, michigan, united states for their help during statistical calculations and analysis.

502 guPta d. et. al

References

1. Jenkins k, graDy D, WonG J, correa R, armanious s, cHunG f: Post-operative recovery: day surgery patients’ preferences. Br J Anaesth; 2001, 86:272-4.

2. macario A, WeinGer m, carney s, kim A: Which clinical anesthesia outcomes are important to avoid? the perspective of patients. Anesth Analg; 1999, 89:652-8.

3. stockDale a, Bellman m: an audit of post-operative pain and nausea in day case surgery. Eur J Anaesthesiol; 1998, 15:271-4.

4. gan tJ: Risk factors for postoperative nausea and vomiting. Anesth Analg; 2006, 102:1884-98.

5. Pueyo fJ, lópez-olaonDo l, sancHez-leDesma mJ, orteGa a, carrascosa f: cost-effectiveness of three combinations of antiemetics in the prevention of postoperative nausea and vomiting. Br J Anaesth; 2003, 91:589-92.

6. subramaniam B, maDan R, saDHasivam s, sennaraj B, tamilselvan P, RajesHwari s, JaGan d, sHenDe d: dexamethasone is a cost-effective alternative to ondansetron in preventing Ponv after paediatric strabismus repair. Br J Anaesth; 2001, 86: 84-9.

7. Hill RP, lubarsky da, PHillips-Bute B, fortney Jt, creeD mR, glass Ps, gan tJ: cost-effectiveness of prophylactic antiemetic therapy with ondansetron, droperidol, or placebo. Anesthesiology; 2000, 92: 958-67.

8. gan tJ, meyer ta, apfel cc, cHunG f, davis PJ, Habib as, Hooper

vd, kovac al, kranke P, myles P, PHilip Bk, samsa g, sessler di, temo J, tramèr mR, vanDer kolk C, WatcHa m: sociEty foR amBulatoRy anEstHEsia: society for ambulatory anesthesia guidelines for the management of postoperative nausea and vomiting. Anesth Analg; 2007, 105:1615-28.

9. gan tJ, diemunscH P, Habib as, kovac a, kranke P, meyer ta, WatcHa m, cHunG f, anGus s, apfel cc, BerGese sd, canDiotti ka, cHan mt, davis PJ, Hooper vd, laGoo-deenaDayalan s, myles P, nezat g, PHilip Bk, tramèr mR: sociEty foR amBulatoRy anEstHEsia: consensus guidelines for the management of postoperative nausea and vomiting. Anesth Analg; 2014, 118:85-113.

10. medpac.gov http://www.medpac.gov/documents/dec05_charge_setting.pdf accessed on april 02, 2014.

11. Habib as, cHen yt, taGucHi a, Hu XH, gan tJ: Postoperative nausea and vomiting following inpatient surgeries in a teaching hospital: a retrospective database analysis. Curr Med Res Opin; 2006, 22:1093-9.

12. Parra-sancHez i, abDallaH R, you J, fu aZ, graDy m, cumminGs k 3rD, apfel c, sessler di: a time-motion economic analysis of postoperative nausea and vomiting in ambulatory surgery. Can J Anaesth; 2012, 59:366-75.

503 M.E.J. ANESTH 22 (5), 2014

The use of AirTrAq lAryngoscope versus MAcinTosh lAryngoscope And fiberopTic bronchoscope by

experienced AnesThesiologisTs

Kemal T. Saracoglu*, muraT acarel**, Tumay umuroglu*** and Fevzi y. goguS****

Abstract

Objective: The aim was to compare the hemodynamic parameters, intubation times, upper airway trauma and postoperative sore throat scores of the patients with normal airway anatomy, intubated with the Airtraq, Macintosh laryngoscope and fiberoptic bronchoscope, by experienced anesthesiologists.

Methods: ninety patients, scheduled to undergo elective surgery under general anesthesia were randomly divided into three groups (n=30): group A: Airtraq laryngoscope, group M: Macintosh laryngoscope and Group FB: fiberoptic bronchoscope. The time to intubation and success rates were recorded. The hemodynamic parameters before and one minute after the anesthesia induction were recorded and the measurements were repeated 3, 4 and 5 minutes after the endotracheal intubation. The postoperative sore throat scores and signs of any trauma were also recorded.

Results: Mean arterial blood pressure and heart rate were not significantly different between the three groups. The mean intubation time interval did not differ between groups. highest postoperative sore throat scores were recorded at the 6th hour post extubation. The scores were 37.6 ± 20.9 in group A, 13.3 ± 16.8 in group M and 13.6 ± 14.0 in group fb. The scores in group A were significantly higher compared to other groups. The number of patients requiring additional analgesia to relieve sore throat was also significantly higher in Group A.

Conclusion: The Airtraq laryngoscope seems to be a more traumatic airway device in the routine endotracheal intubation compared to Macintosh laryngoscope and fiberoptic bronchoscope, when used by experienced anesthesiologists. It also does not offer advantage over the first-attempt success rates, the intubation times and hemodynamic parameters.

Keywords: airway management; laryngoscope; Airtraq; Macintosh laryngoscope; fiberoptic bronchoscope; intubation.

* Assistant prof. Md.** Md.*** Assoc. prof. Md.**** prof. Md. Affiliation: Department of Anesthesiology, Marmara University School of Medicine, Istanbul, Turkey. Corresponding author: Kemal Tolga sArAcoglu. department of Anesthesiology, Marmara university school of

Medicine, Fevzi Cakmak Mah. Ust Kaynarca, Pendik, Istanbul, Turkey. Tel: +902166570606, Fax: +902164144731. E-mail: [email protected]

504 sArAcoglu K.T. et. al

Introduction

Recent technological advances including the light-emitting diodes, rechargeable batteries, optical systems with adjustable position capability and modified laryngoscope blades allowed the development of new devices such as Airtraq laryngoscope (Airtraq, prodol Meditec limited, china), to facilitate and improve the success rate of endotracheal intubation1,2. Although originally designed to facilitate difficult intubation, thesee devices can also be used in the management of the normal airway1,2.

The special design of the Airtraq allows the direct exposure of the glottic opening without the necessity of optimal alignment of the oral, pharyngeal and laryngeal axes. The results of the meta-analysis comparing the Airtraq with the conventional Macintosh laryngoscope concluded that the use of Airtraq results in a rapid and accurate intubation3. The Macintosh laryngoscope possess a curved blade facilitating the glottic view, reducing potential tongue and epiglottic trauma. The use of the fiberoptic bronchoscope (FOB, Pentax Corporation, Japan) is of great value in performing endotracheal intubation, but with the main disadvantage for being of high cost, and the need for long practical experience.

studies on the effectivity and complications of the Airtraq and FOB are mainly conducted on manikins5-8. in these studies, the intubations are mainly performed by novices or paramedics5,6. To our knowledge, a comparison of the endotracheal intubation with Airtraq, Macintosh laryngoscope and fob performed by the experienced anesthesiologists is lacking. furthermore, determination of the postoperative sore throat incidence and airway trauma is not possible in manikins or in simulation scenarios.

The purpose of this study was to compare the hemodynamic parameters, intubation times, complications during and after intubation and postoperative sore throat scores of the patients having normal airway anatomy, intubated with Airtraq, Macintosh laryngoscope or FOB, by experienced anesthesiologists. The primary outcome variables were the first-attempt success rate, time to successful intubation. The secondary outcome variables were the effects of the intubation on hemodynamic parameters,

the postoperative sore throat scores and trauma to the upper airways.

Methods

following the approval of the Marmara university ethics committee, 90 patients, aged between 18-65 years, with American Society of Anesthesiologists (ASA) physical status classification of 1 or 2, undergoing elective surgery under general anesthesia and requiring endotracheal intubation were included in the study. The exclusion criteria for participation in this study were: patients with AsA 3 or 4, Mallampati score of 3 or 4, history of difficult intubation, thyromental distance less than 6.5 cm, sternomental distance less than 12.5 cm, body mass index higher than 35 kg/m2 and limited neck mobility.

All patients gave their written informed consent. A prospective and randomised study design was employed and the randomisation was done with the help of a random number generator downloaded from ‘http//www.random.org’9. The endotracheal intubations were performed by three experienced anesthesiologists. Anesthesiologists who had practiced at least 500 intubations with the Macintosh laryngoscope, 50 intubations with the fob were considered as being ‘experienced’10. The preoperative Mallampati scores were recorded and maximum mouth opening, thyromental and sternomental distances of the patients were measured. All patients were premedicated with 0.015 mg/kg IM atropine sulphate and 0.07 mg/kg IM midazolam. The patients’ positions in the operation room were supine with no pillow under the head. Monitoring included electrocardiogram, noninvasive blood pressure and peripheral pulse oximetry (SpO2), end tidal carbon dioxide (ETCO2) and end tidal sevoflurane concentrations. Preoxygenation was not performed. Anesthesia was induced with 5-7 mg/kg IV thiopental sodium and 0.6 mg/kg IV rocuronium bromide. The administration of the opioid analgesics was not allowed in the induction period.

The patients were randomly divided into three groups (n=30) and orotracheal intubated with Airtraq (group A), Macintosh laryngoscope (group M) and fob (group fb). in group A, the standard inventor’s technique was used. Airtraq was positioned into the

M.E.J. ANESTH 22 (5), 2014

505The use of AirTrAq lAryngoscope versus MAcinTosh lAryngoscope And fiberopTic bronchoscope by experienced AnesThesiologisTs

vallecula and upward lifting of the epiglottis made glottic opening visible. The tube was then inserted to the trachea. in group M, direct laryngoscopy was performed with a Macintosh blade size 3. in group fb, endotracheal intubation was performed with a fob with attached tracheal tube. if a satisfactory vision was not achieved in any group, the applications of optimization maneuvers such as jaw thrust, tracheal pressure, lifting, tilting or orientation of devices or the assistance of a second person were allowed and recorded. Train-of-four (TOF) (Watch SX; Organon ltd drynam road swords, co. dublin, ireland) was used to measure the level of neuromuscular blockade. Anesthesia was maintained with 1 MAC sevoflurane and %70 N2O in oxygen.

The intubation time (the time from the device insertion into the oral cavity and the view of the tube crossing the vocal cords) was measured by a chronometer. The intubation was failed, if it could not be performed less than 120 seconds. in this instance the patient was excluded from the study. complications such as esophageal intubation, upper airway mucosa laceration, dental trauma or iatrogenic endotracheal cuff rupture were noted. The success or failure of the process was also recorded. Mean arterial blood pressure, heart rate, spo2 and eTco2 concentrations were measured before the anesthesia induction (0. min) and one min after the induction. The time interval between anesthesia induction and endotracheal intubation was considered to be 2 min. hemodynamic parameters were also recorded 3, 4 and 5 min after the intubation.

Meperidine hydrochloride 1 mg/kg IV was administered to all patients in the early postoperative

period. At the end of 30 minutes, the sore throat scores of the patients were evaluated after direct questioning, using a 0-100 mm visual analogue scale (VAS). postoperative sore throat vAs scores were recorded at the 6th, 12th and 24th hour. The anesthesiologist evaluating the postoperative sore throat scores was blinded to the intubation devices used. patients having vAs scores higher than 30 mm were administered 20 mg iv meperidine hydrochloride as a rescue analgesic. In all patients, 1 mg/kg meperidine hydrochloride IV was given every 6 h for the first 24 h, as a postoperative analgesia.

Statistical Package for Social Sciences for Windows (SPSS) version 20.0 (SPSS Inc., Chicago, il, usA) was used for the statistical analysis. one of the primary outcomes was the time to successful tracheal intubation. based on previously published studies11,12, we estimated that 24 patients would be required for each group to detect a mean difference of 6 seconds in the overall duration of intubations, between groups, with a power of 80% and a significance level (a) of 0.05. so, we enrolled 30 patients per group. data are summarized using mean ± sd for continuous variables. statistical comparisons between the groups were performed using analysis of variance (AnovA) with Kramer as a post hoc test. repeated parameters were analysed by repeated measures AnovA, with Newman-Keuls as a post hoc test. Data for the success of tracheal intubation attempts, the differences between patients with or without complications were investigated by Fisher’s exact test. P < 0.05 was considered statistically significant.

Table 1 Patient characteristics of groups

Group A Group M Group FB P

Age (Years) 42.3 ± 13.5 40.7 ± 17.0 43.2 ± 14.5 0. 631

Weight (kg) 72.7 ± 12.9 70.7 ± 13.0 73.3 ± 13.1 0.891

Height (cm) 168.6 ± 9.5 166.9 ± 9.4 169.8 ± 9.6 0. 631

Male/Female ratio 16/15 14/16 15/15 0.875

Sternomental distance (cm) 13.6 ± 1.9 13.5 ± 1.0 13.8 ± 1.4 0. 491

Thyromental distance (cm) 7.41±1.54 7.36±1.63 7.93±1.78 0.265

506

endotracheal intubation (Table 1 and 2). The mean arterial blood pressure and the heart rate values of the three study groups were not significantly different throughout the study period (Figure 1 and 2). End-tidal carbon dioxide concentrations were 34.16, 33.18 and 32.68 mmhg in groups A, M, fb respectively and spo2

values were 98.36%, 98.54% and 98.62% in groups A, M, FB respectively in the first 5 min, with no statistical

sArAcoglu K.T. et. al

Results

ninety patients were included in the study. demographic data of the three groups were similar (Table 1). There were no statistical differences between groups regarding maximum mouth opening, sternomental and thyromental distance and time to

Fig. 1 Mean arterial blood pressure (mmHg)

T1: 0. min, T2: 1. min, T3: 2. min, T4: 3. min, T5: 4. min, T6: 5. Min

Fig. 2 Heart rate (beat/min)

T1: 0. min, T2: 1. min, T3: 2. min, T4: 3. min, T5: 4. min, T6: 5. Min

Table 3 Patients requesting additional analgesia to relieve sore throat


30. min *46.6 % 13.3 % 6.6 % 0.000

6. h *63.3 % 23.3 % 16.6 % 0.000

12. h *50.0 % 16.6 % 13.3 % 0.002

24. h *50.0 % 6.6 % 3.3 % 0.000

* Difference with Group A p < 0.05.

Table 2 Maximal mouth opening (cm), intubation time (sec) and first attempt success rate


Maximal mouth opening (cm) 5.1 ± 1.71 4.7 ± 1.41 4.45 ± 0.69 0. 223

Intubation time (sec) 11.23 ± 2.90 9.46 ± 2.70* 9.96 ± 1.82 0.009

First attempt success rate 4 (13.3%) 2 (6.7%) 2 (6.7%) 0.578

End-tidal CO2 34.16±2.19 33.18±2.47 32.68±2.92 0.192

* Difference with Group A p < 0.05.

M.E.J. ANESTH 22 (5), 2014


difference between groups. The highest postoperative sore throat vAs scores were recorded at the 6th h in all groups, the significantly highest scores were found in group A (figure 3). At all times, sore throat vAs scores of the group A were significantly higher compared to other groups (p< 0.01) (Figure 3). The percentage of patients requiring rescue analgesics to sore throat was significantly higher in group A (p< 0.05) (Table 3). All patients in the study were successfully intubated. on removal of the laryngoscope following intubation, blood spot on the blade was observed in 4 patients in group A, but a detailed intraoral examination revealed nolaceration or lesion. complications such as esophageal intubation, dental trauma or iatrogenic endotracheal tube cuff rupture were not observed in any patients in all groups. The help of another anesthesiologist was required in 4 patients in group A and for 2 patients in group f. The rotation maneuver was used in 6 patients in group A. none of the patients in all groups required jaw thrust maneuver.

Discussion

The results of the present study indicate that the use of Airtraq by experienced anesthesiologists may be more traumatic in the endotracheal intubation of patients with normal airways, without shortening the time for successful intubation when compared to Macintosh laryngoscope and fob.

Airtraq use on manikins and simulators is widely investigated in novices, but little is known about the efficacy and complications of the Airtraq device when used by experienced anesthesiologists13,14. Furthermore, the exact incidence of sore throat

or mucosal injury caused by the Airtraq is hard to determine, because studies on this field are mainly manikin studies. Airtraq facilitates endotracheal intubation in a more rapid manner than the Macintosh laryngoscope and it is user friendly, especially when used by novices3. its main advantage is that it allows the visualization of the glottis without the need of alignment of the oral, pharyngeal and tracheal axes. The Macintosh laryngoscope retracts the tongue and epiglottis, exposing the oral, pharyngeal and tracheal axes in a straight line. Correct laryngoscope handling and correct interaction of the Macintosh blade with the perilaryngeal structures necessitate anesthesiologist’s experience, whereas Airtraq may easily be used by unskillful anesthesiologist residents or novices15. The superiority of the Airtraq over Macintosh laryngoscope in patients at increased risk for difficult intubation and simulated difficult airway scenarios has been demonstrated, when used by experienced anesthesiologists16,17. it also seems that the Airtraq may be a good choice for the use by novices and inexperienced laryngoscopists who are not used to perform routine endotracheal intubation. nevertheless, to our knowledge there is no clinical study comparing the hemodynamic parameters, intubation times, sore throat scores and upper airway trauma incidence in patients with normal airways intubated with fiberoptic bronchoscope, Airtraq and Macintosh laryngoscope, by experienced anesthesiologists.

hemodynamic parameters and time to intubation were similar between groups, indicating that Airtraq does not offer any advantage in these regards. These results are not surprising since anesthesiologists involved to the study are all experienced in the use of these devices.

The presence of blood spot on the tip of the device and significantly high postoperative sore throat scores in our patients intubated with Airtraq, suggest that the Airtraq may be a potentially traumatic device, when used in patients with normal airway anatomy. upper airway injury is possible during laryngoscopy18. dental trauma, tongue lacerations or hematomas are the most commonly encountered upper airway injuries related to the use of various endotracheal intubation devices. injury to the tongue is usually related to the force applied by the laryngoscope on the tongue19.

Fig. 3 VAS scores of patients for postoperative sore throat

508 sArAcoglu K.T. et. al

Gaszynski20 suggested that the use of Airtraq resulted in less pressure on the tongue compared to the Macintosh laryngoscope. We observed blood spot on the tip of the device in 4 patients, following the removal of the Airtraq. Although a detailed intraoral examination revealed no laceration, we suggested that the Airtraq use may result in minor trauma to the upper airway. The presence of blood on the tip of the device suggests that trauma made by the Airtraq is not related to the force applied on the tongue, but on the force applied to the vallecula. similar to Macintosh laryngoscope, adjusting the position of Airtraq in the pharynx is required. in accordance with the habituel practice with Macintosh laryngoscope or to optimise the view of the glottis, the blade of the Airtraq can be intuitively lifted up. in the literature, some intuitive small amplitude movements performed by the anesthesiologists are already described21. These maneuvers may easily harm the vallecula in normal airways. Maharaj et al.10 suggested that in patients at increased risk for difficult tracheal intubation, minor force has to be applied during laryngoscopy with the Airtraq device because there is no need to align the oral, pharyngeal and tracheal axes. Depending on previous studies demonstrating the success of Airtraq on tracheal intubation in patients with difficult airway, it may be hypothesized that the exaggerated curvature of the Airtraq blade may easily improve the glottic exposure in abnormal airways with anteriorly located larynx22,23. dhonneur et al.21 found that anaesthesiologists learning to use the Airtraq in patients with potentially difficult airways, are placing the Airtraq in the pharynx with a significant distal pressure on the tip of the blade to overcome the narrowing at the junction between the oral and pharyngeal spaces. We suggest that in normally positioned larynx also, the tip of the blade may apply some pressure to the vallecula. A detailed examination of the upper airway did not reveal any mucosal injury but the examination of the vallecula was not performed in order not to affect the postoperative sore throat scores.

A positive correlation is determined between force used during intubation attempts and incidence of complications such as sore throat intensity19.

postoperative sore throat scores were high in the Airtraq group. optimization maneuvers were common in the use of Airtraq and in order to perform the intubation, the rotation maneuver was obligatory in 6 patients intubated with Airtaq. These findings may also explain that more forces had to be applied to the patients during the use of Airtraq.

The major limitation of our study was that we did not record any videos during airway manipulation of the patients and internal views of the larynx.

Conclusion

The Airtraq use in patients with normal airway anatomy may result in minor upper airway trauma and significant sore throat. Experienced anesthesiologists are able to intubate the patients with normal airway anatomy with devices requiring skill and familiarity, such as Macintosh laryngoscope or fob. According to the results of this study, we underline that the Airtraq should not take place in the routine endotracheal intubation practice of the patients with normal airways, in the hands of experienced anesthesiologist; the use of the airtraq should be limited to the manipulation of patients with difficult airways and limited neck extension.

Acknowledgments

The authors would like to acknowledge Yigit Medical Systems, Ankara, Turkey for loan of Airtraq devices for this study. The authors declare no financial support or sponsorship.

Abbreviations

FOB: fiberoptic bronchoscope, ASA: American society of Anesthesiology, iM: intramuscular, iv: intravenous, spo2: peripheral pulse oximetry, ETCO2: end tidal carbon dioxide, TOF: Train-of-four, VAS: visual analogue scale, SPSS: Statistical Package for Social Sciences for Windows, ANOVA: analysis of variance.

M.E.J. ANESTH 22 (5), 2014


References

1. Saracoglu KT, eTi z, goguS Fy: Airtraq optical laryngoscope: advantages and disadvantages. Middle East J Anesthesiol; 2013, 22:135-141.

2. Thong Sy, lim y: video and optic laryngoscopy assisted tracheal intubation--the new era. Anaesth Intensive Care; 2009, 37:219-233.

3. lu y, Jiang h, zhu yS: Airtraq laryngoscope versus conventional Macintosh laryngoscope: a systematic review and meta-analysis. Anaesthesia; 2011, 66:1160-1167.

4. chandra dB, Savoldelli gl, Joo hS, WeiSS id, naiK vn: Fiberoptic oral intubation: the effect of model fidelity on training for transfer to patient care. Anesthesiology; 2008, 109:1007-1013.

5. leWiS ar, hodzovic i, Whelan J, WilKeS ar, BoWler i, WhiTField r: A paramedic study comparing the use of the Airtraq, Airway scope and Macintosh laryngoscopes in simulated prehospital airway scenarios. Anaesthesia; 2010, 65:1187-1193.

6. maharaJ ch, coSTello JF, higginS Bd, harTe Bh, laFFey Jg: learning and performance of tracheal intubation by novice personnel: a comparison of the Airtraq and Macintosh laryngoscope. Anaesthesia; 2006, 61:671-677.

7. maharaJ ch, higginS Bd, harTe Bh, laFFey Jg: evaluation of intubation using the Airtraq or Macintosh laryngoscope by anaesthetists in easy and simulated difficult laryngoscopy – a manikin study. Anaesthesia; 2006, 61:469-477.

8. niShiKaWa K, huKuoKa e, KaWagiShi T, ShimodaTe y, yamaKage me: Efficacy of the Airtraq(®) laryngoscope with a fiberoptic bronchoscope compared with that of Airtraq(®) alone for tracheal intubation: a manikin study. J Anesth; 2011, 25:93-97.

9. mcelWain J, maliK ma, harTe Bh, Flynn nm, laFFey Jg: Comparison of the C-MAC videolaryngoscope with the Macintosh, Glidescope, and Airtraq laryngoscopes in easy and difficult laryngoscopy scenarios in manikins. Anaesthesia; 2010, 65:483-489.

10. maharaJ ch, coSTello JF, harTe Bh, laFFey Jg: evaluation of the Airtraq and Macintosh laryngoscopes in patients at increased risk for difficult tracheal intubation. Anaesthesia; 2008, 63:182-188.

11. chalKeidiS o, KoTSovoliS g, KalaKonaS a, Filippidou m, TrianTaFyllou c, vaiKoS d, KouTSioumpaS e: A comparison between the Airtraq and Macintosh laryngoscopes for routine airway management by experienced anesthesiologists: a randomized clinical trial. Acta Anaesthesiol Taiwan; 2010, 48:15-20.

12. maharaJ ch, o’croinin d, curley g, harTe Bh, laFFey Jg: A

comparison of tracheal intubation using the Airtraq or the Macintosh laryngoscope in routine airway management: A randomised, controlled clinical trial. Anaesthesia; 2006, 61:1093-1099.

13. di marco p, ScaTToni l, Spinoglio a, luzi m, canneTi a, pieTropaoli p, reale c: learning curves of the Airtraq and the Macintosh laryngoscopes for tracheal intubation by novice laryngoscopists: a clinical study. Anesth Analg; 2011, 112:122-125.

14. maharaJ ch, BucKley e, harTe Bh, laFFey Jg: endotracheal intubation in patients with cervical spine immobilization: a comparison of macintosh and airtraq laryngoscopes. Anesthesiology; 2007, 107:53-59.

15. Ferrando c, aguilar g, Belda FJ: comparison of the laryngeal view during Tracheal intubation using Airtraq and Macintosh Laryngoscopes by Unskillful Anesthesiology Residents: A Clinical study. Anesthesiol Res Pract; 2011, 2011:301057.

16. legrand ma, STeinmann d, prieBe hJ, molS g: comparison of bullard and Airtraq laryngoscopes with conventional laryngoscopy in a manikin study of simulated difficult intubation. Eur J Anaesthesiol; 2012, 29:343-350.

17. ST monT g, BieSler i, pFörTner r, mohr c, groeBen h: easy and difficult nasal intubation-a randomised comparison of Macintosh vs Airtraq® laryngoscopes. Anaesthesia; 2012, 67:132-138.

18. divaTia J, BhoWmicK K: complications of endotracheal intubation and other airway management procedures. Indian J Anaesth; 2005, 49:308-308.

19. haShemi S, SolTani h, Saeid r: forces applied by the laryngoscope blade onto basis of the tongue and their relation with postoperative sore throat. Med J Islamic World Acad Sci; 2004, 16:189-193.

20. gaSzynSKi Tm: forces applied by the laryngoscope blade onto the tongue during intubation attempts: a comparison between Macintosh, AirTraq and Pentax AWS in a mannequin study. Eur J Anaesthesiol; 2011, 28:463-464.

21. dhonneur g, aBdi W, amaThieu r, ndoKo S, Tual l: optimising tracheal intubation success rate using the Airtraq laryngoscope. Anaesthesia; 2009, 64:315-319.

22. KriShna hm, BhagaT S, vinodhadevi v: Difficult intubation in an infant with Hallermann-Streiff syndrome-easy with Airtraq laryngoscope. Paediatr Anaesth; 2012, 22:497-498.

23. Xue FS, he n, liu Jh, liao X, Xu Xz: Airway topical anesthesia using the Airtraq laryngoscope in patients with difficult airways. Can J Anaesth; 2009, 56:777-778.

511 M.E.J. ANESTH 22 (5), 2014

CASE REPORTS

UltrasoUnd-gUided regional anesthesia in a pediatric patient with acUte intermittent porphyria: literatUre review and case report

Yetunde Olutunmbi*, HarsHad G. GurnaneY**, JOrGe a. Galvez* and allan F. simpaO*

Abstract

Ultrasound-guided regional anesthesia techniques placed under general anesthesia have not been reported in pediatric patients with acute intermittent porphyria (aip). a 9-year-old male with aip presented for right inguinal herniorraphy. Family history included one relative’s death after anesthesia. preoperative preparation included reviewing medications safe for aip patients, minimizing known aip triggers (fasting, stress) and ensuring access to rescue medications. intraoperative management included a propofol induction with the patient’s mother present in the operating room. we performed an ultrasound-guided ilioinguinal-iliohypogastric nerve block under general anesthesia. the surgery proceeded without complications and the patient did not demonstrate signs of an aip crisis.

Sources of financial support: this study was funded solely with departmental funding.

Introduction

Acute intermittent porphyria (AIP) is an autosomal dominant deficiency in porphobilinogen deaminase that can manifest as a sudden, possibly fatal neurovisceral crisis, symptoms of which include severe abdominal pain, seizures, respiratory and limb weakness, hypertension, and tachycardia1,2. in rare occasions, aip may present with symptomatic hyponatremia secondary to syndrome of inappropriate antidiuretic hormone secretion3 acute pancreatitis4, or spontaneous hemothorax5. triggers include many aspects of the perioperative setting, such as fasting, stress, dehydration and medications6.

* md.** mBBs, mph. Affiliation: Department of Anesthesiology and Critical Care Medicine, Perelman School of Medicine at the University of

pennsylvania and the children’s hospital of philadelphia, philadelphia, pa. Corresponding author: allan F. simpao, md; department of anesthesiology and critical care medicine at perelman school

of medicine at the University of pennsylvania and the children’s hospital of philadelphia, 34th street and civic center Blvd., suite 9329, philadelphia, pa, 19104, tel: 1-215-590-1000, Fax: 1-215-590-1415. e-mail: [email protected]

512 olUtUnmBi y. et. al

Case Description

A 9-year-old, 25.7 kg male with a confirmed genetic marker for acute intermittent porphyria (aip) presented for right inguinal hernia repair. clinical signs on admission included an innocent heart murmur and anxiety. the family history was rife with anesthetic complications: one relative died on induction with a barbiturate, an aunt had an aip episode while under anesthesia necessitating alkaline heme treatments, and the patient’s mother had “nearly died” during an anesthetic for cardiac surgery.

pre-operative management included a thorough aip literature search, a metabolism and genetics consultation, and extensive communication with the surgeon and the patient’s mother prior to the surgery. evidence-based lists of safe medications in aip were reviewed7 and a clinical pharmacist was contacted to verify the information. gabapentin and hemin were ordered and available in the pharmacy in case of a crisis8,9.

the patient was encouraged to drink clear white grape juice until 2 hours prior to surgery. on the recommendation of metabolism/genetics, the patient received an intravenous (iv) catheter in the holding area, and an infusion of dextrose 10%/saline 0.45% (d10/0.5ns) was started. a comprehensive metabolic profile was checked to rule out inappropriate secretion of antidiuretic hormone; the lab values were in the normal range. in lieu of administering oral midazolam (due to conflicting safety data in AIP patients), we arranged a parental induction and gave iv fentanyl for mild sedation prior to transport into the operating room.

we performed a parental-presence iv induction with propofol, placed a laryngeal mask airway (lma) and administered sevoflurane. We performed a right-sided ultrasound-guided ilioinguinal-iliohypogastric nerve block using a sonosite s (sonosite, Bothell, wa) with an l25X (6-13 mhz) probe with clear visualization of both nerves. Four ml of 0.25% bupivacaine with 1:200,000 epinephrine were injected with satisfactory spread of local anesthetic visualized with the ultrasound in the plane between the internal oblique and the transversus abdominis muscles around the two nerves (Fig. 1). the d10/0.5ns infusion was

continued; a glucose check was within the normal range. patient temperature was maintained between 36-38c via an underbody circulating water mattress and an upper body forced-air blanket.

Fig. 1 Ultrasound-guided ilioinguinal-iliohypogastric

nerve block

during the procedure, a left inguinal hernia and undescended left testes were discovered by the surgeon. the patient’s mother was contacted and she consented to a bilateral surgical procedure. the patient was given a 1.5 mg of iv morphine bolus prior to the initiation of the left-sided portion of the procedure. ondansetron 4mg iv was administered during skin closure. to minimize the stress of emergence, we removed the lma under deep plane of anesthesia (i.e., 1.3 mac) after ensuring that the patient was breathing spontaneously with tidal volumes of approximately 5-6 ml/kg. a plastic oral airway was placed to maintain airway patency.

the patient was transported uneventfully with supplemental oxygen delivered via a mapleson circuit and face mask to the post-anesthesia care unit (pacU), where he emerged safely from anesthesia. the patient received a total of two 1mg boluses of iv morphine over the following 15 minutes for reported 5/10 pain located in the left inguinal region. there were no aip sequelae noted (e.g. abdominal pain, neurological findings) and vital signs were stable throughout the two-hour pacU stay prior to discharge home.

A nurse practitioner spoke with the mother during a post-operative phone call 72 hours after discharge

M.E.J. ANESTH 22 (5), 2014

513UltrasoUnd-gUided regional anesthesia in a pediatric patient with acUte intermittent porphyria: literatUre review and case report

and determined that no AIP symptoms nor anesthesia-related problems had occurred. Furthermore, the patient had no new complaints nor any reported AIP-related symptoms at his one-month follow-up visit with the surgeon.

the institutional review Board at the children’s hospital of philadelphia gave permission to publish this report and written informed consent was obtained from the parent of the patient.

Discussion and Literature Review

acute intermittent porphyria is caused by an inherent error of porphyrin metabolism characterized by a deficiency of porphobilinogen deaminase and increased activity of delta-aminolevulinic acid synthase. an increased concentration of heme precursors results from the dysfunction of these two key heme biosynthesis enzymes10,11.

porphyric crisis can be precipitated by many anesthetic and nonanesthetic drugs6,12,13. the medications that are recommended as safe for use in anesthesia for aip patients is largely based on cumulative anecdotal experiences (i.e. case reports and case series)13,14. a constantly updated list is maintained by the american porphyria Foundation, which rates medications’ safety in aip patients based on evidence in the literature7, in light of this patient’s strong family history of anesthesia-related aip complications, the decision was made in conjunction with the patient’s mother to use solely those medications that had received the top safety rating of “oK!” (i.e. “very likely to be safe for prolonged use by individuals with an acute porphyria, based on consistent evidence”). the list of planned perioperative medications was verified as safe by a clinical pharmacist.

acute seizures can present a treatment challenge in aip patients, as some medications given to ameliorate acute seizures (e.g. barbiturates) are either known or questionable aip crisis precipitants13. lorazepam and magnesium have been shown to be safe treatments for acute seizures in aip patients15,16. gabapentin-a gaBa analog prescribed commonly both as an antiepileptic drug and to treat neuropathic pain-has been shown to be a safe, effective treatment of status epliepticus due to aip8,17. Gabapentin pharmacokinetic profiles in

children ages 1 month to 12 years has shown similar peak plasma concentrations across the entire age group after a single dose of 10 mg/kg, and gabapentin doses of 24 to 70 mg/kg/day were shown to be well tolerated and have sustained efficacy in a large population of children aged 3 to 12 years18,19,20. if seizures continue despite gabapentin administration, then propofol (1-1.5 mg/kg iv bolus over 5 min followed by 1-2mg/kg/hr iv infusion) can be delivered as a concurrent treatment21. electrolyte abnormalities that are associated with aip and can cause seizures (e.g. hyponatremia) should be corrected2,3.

hemin (i.e. exogenous heme) was made available preoperatively as a precaution. hemin has been shown to be an effective treatment for acute aip attacks after conservative measures have been employed (e.g. iv fluids containing carbohydrates); hemin ameliorates symptoms via down-regulation of aminolevulinic acid synthase22,23,24,25. side effects experienced in cases of overdose or overly rapid administration include reversible renal shutdown and liver failure26,27.

in addition to extensive medication safety review and preparations, thorough precautions were taken to limit non-pharmacological stressors that might precipitate an aip attack1,2. Both a liberal fasting protocol and preoperative iv placement with administration of dextrose-containing fluids were initiated to minimize dehydration and calorie restriction1,3. a parental-presence induction, placement of a regional block, and lma removal under a deep plane of anesthesia were all undertaken to minimize the stresses of anxiety and pain. lastly, steps were taken to identify aip crisis sequelae (e.g. preoperative comprehensive metabolic panel to assess for hyponatremia)3.

while regional techniques in aip patients have been reported in the literature28,29,30, ultrasound-guided regional anesthesia techniques placed under general anesthesia have not been described in pediatric patients with acute intermittent porphyria. in summary, we present a successful general and ultrasound-guided regional anesthetic course in a high-risk pediatric aip patient following the careful selection of safe perioperative and rescue medications, liberal fasting policy and preoperative administration of dextrose-containing IV fluids, and vigilant minimization of other potential aip crisis precipitants.

514 olUtUnmBi y. et. al

References

1. piscHik e, Kauppinen r: neurological manifestations of acute intermittent porphyria. Cell Mol Biol; 2009, 55:72-83.

2. BYlesJö i, FOrsGren l, litHner F, BOman K: epidemiology and clinical characteristics of seizures in patients with acute intermittent porphyria. Epilepsia; 1996, 37:230-5.

3. gázquez sisteré i, luJán mavila K, cHOrdá ribelles J, tOuzón lópez c: acute intermittent porphyria: a diagnostic dilemma. Gastroenterol Hepatol; 2010, 33:436-9.

4. sHen Fc, hsieH ch, huanG cr, lui cc, tai wc, cHuanG yc: acute intermittent porphyria presenting as acute pancreatitis and posterior reversible encephalopathy syndrome. Acta Neurol Taiwan; 2008, 17:177-83.

5. BuitraGO J, santa sv: acute intermittent porphyria presenting as spontaneous hemothorax. Biomedica; 2009, 29:339-47.

6. sHeppard l, dOrman t: anesthesia in a child with homozygous porphobilinogen deaminase deficiency: a severe form of acute intermittent porphyria. Ped Anesth; 2005, 15:426-8.

7. american porphyria Foundation. available at http://www.porphyriafoundation.com/testing-and-treatment/drug-safety-in-acute-porphyria. accessed april 1, 2014.

8. Zadra m, grandi r, erli lc, mirabile d, Brambilla a: treatment of seizures in acute intermittent porphyria: safety and efficacy of gabapentin. Seizure; 1998, 7:415-6.

9. mutHane UB, venGamma B, BHaratHi Kc, mamatHa p: porphyric neuropathy: prevention of progression using haeme-arginate. J Intern Med; 1993, 234:611-3.

10. KHanderia U, BHattacHarYa a: acute intermittent porphyria: pathophysiology and treatment. Pharmacotherapy; 1984, 4:144-50.

11. BlOOmer Jr, BOnkOvskY hl: the porphyrias. Dis Mon; 1989, 35:1-54.

12. disler pB, mOOre mr: drug therapy in the acute porphyrias. Clin Dermatol; 1985, 3:112-24.

13. James mFm, hiFt rJ: porphyrias. Br J Anesth; 2000, 85:143-53.14. hsieH ch, hunG pc, cHien ct, sHiH yr, penG sK, luk hn, tsai

TC: The use of rocuronium and sevoflurane in acute intermittent porphyria-a case report. Act Anaesthesiol Taiwan; 2006, 44:169-71.

15. hOlrOYd s, seward rl: psychotropic drugs in acute intermittent porphyria. Clin Pharmacol Ther; 1999, 66:323-5.

16. sadeH m, Blatt i, martOnOvits g, Karni a, gOldHammer y: treatment of porphyric convulsions with magnesium sulfate. Epilepsia; 1991, 32:712-5.

17. tatum wo 4tH, ZacHariaH sB: gabapentin treatment of seizures in acute intermittent porphyria. Neurology; 1995, 45:1216-7.

18. haiG gm, BOckbrader hn, wescHe dl, BOellner sw, ouellet d, BrOwn rr, randinitis eJ, pOsvar el: single-dose gabapentin pharmacokinetics and safety in health infants and children. J Clin Pharmacol; 2001, 41:507-14.

19. appletOn r, FicHtner K, lamOreaux l, alexander J, matOn s, murraY g, garOFalO e: gabapentin as add-on therapy in children with refractory partial seizures: a 24-week, multicentre, open-label study. Dev Med Child Neurol; 2001, 43:269-73.

20. mclean mJ, gidal Be: gabapentin dosing in the treatment of epilepsy. Clin Ther; 2003, 25:1382-406.

21. pandeY cK, sinGH n, BOse n, saHaY s: gabapentin and propofol for treatment of status epilepticus in acute intermittent porphyria. J Postgrad Med; 2003, 49:285.

22. petersOn a, BOssenmaier i, cardinal r, watsOn cJ: hematin treatment of acute porphyria. early remission of an almost fatal relapse. JAMA; 1976, 235:520-2.

23. Bissell dm: treatment of acute hepatic porphyria with hematin. J Hepatol; 1988, 6:1-7.

24. mustaJOki p, nOrdmann y: early administration of heme arginate for acute porphyric attacks. Arch Intern Med; 1993, 153:2004-8.

25. BOnkOvskY hl, healeY JF, lOurie an, gerrOn gg: intravenous heme-albumin in acute intermittent porphyria: evidence for repletion of hepatic hemoproteins and regulatory heme pools. Am J Gastroenterol; 1991, 86:1050-6.

26. dHar gJ, BOssenmaier i, cardinal r, petrYka ZJ, watsOn cJ: transitory renal failure following rapid administration of a relatively large amount of hematin in a patient with acute intermittent porphyria in clinical remission. Acta Med Scand; 1978, 203:437-43.

27. Frei p, minder ei, cOrti n, muellHaupt B, geier a, adams h, dutertre Jp, rudiGer a, dutkOwski p, maGGiOrini m, ganter cc: liver transplantation because of acute liver failure due to heme arginate overdose in a patient with acute intermittent porphyria. Case Rep Gastroenterol; 2012, 6:190-6.

28. mcneill mJ, Bennet a: Use of regional anaesthesia in a patient with acute porphyria. Br J Anaesth; 1990, 64:371-3.

29. BöHrer h, scHmidt h: regional anesthesia as anesthetic technique of choice in acute hepatic porphyria. J Clin Anesth; 1992, 4:259.

30. riGal Jc, BlanlOeil y: anaesthesia and porphyria. Minerva Anestesiol; 2002, 68:326-31.

515 M.E.J. ANESTH 22 (5), 2014

Anesthetic considerAtions And MAnAgeMent of A PAtient with UnsUsPected cArcinoid

crisis dUring hePAtic tUMor resection

Clark k. Choi*

Abstract

Anesthetic management for massive blood loss in liver surgery concomitant with hemodynamic instability secondary to carcinoid crisis can be challenging in the perioperative setting. Hypotension, diarrhea, facial flushing, bronchospasm, and tricuspid and pulmonic valvular diseases are the common manifestations of carcinoid syndrome. this report illustrates the importance of early recognition and treatment for signs and symptoms of carcinoid syndrome not only in the preoperative setting but also in the intraoperative phase to prevent undue cardiovascular collapse.

Keywords: octreotide, carcinoid crisis, neuroendocrine hepatic tumor, hypotension.

Introduction

Carcinoid tumor is a rare form of neuroendocrine cancer that is derived from enterochromaffin cells. Approximately 74% of carcinoid tumors originate from the gastrointestinal tract, most commonly from the small bowel (29%) and appendix (19%), and 25% from the lungs1. the annual incidence is reported to be 0.28 per 100,000 population2. the tumor secretes serotonin, histamine, bradykinins, and vasoactive intestinal peptides that produce vessel permeability, hypotension, flushing, diarrhea, and wheezing when released into the systemic circulation from liver metastases or extrahepatic carcinoid tumor during surgical manipulation3.

Case Report

A 64-year-old male (83 kg, 185 cm) with past medical history of hyperlipidemia and left hepatic tumor, presented with bronchitis, diarrhea, and flushing for 9 months. A liver biopsy confirmed intermediate grade neuroendocrine tumor of unknown primary neoplasm. The patient underwent hepatic artery embolization and received monthly somatostatin depot for symptomatic relieve before he was evaluated for surgical intervention.

* Md, Ms. Corresponding author: clark K. choi. department of Anesthesiology and Perioperative Medicine, the University of texas

Md Anderson cancer center, 1515 holcombe Boulevard, houston, tX 77030. tel: (718) 909-6806, fax: (713) 563-3808. e-mail: [email protected]

516 choi c. K.

on the day of surgery, the patient appeared well-nourished with stable vital signs (BP=114/69 mmhg, P=79 beats/min, rr=18 breaths/min, spo2=98%, and t=37 ºc). electrocardiogram and chest radiography revealed sinus rhythm and no metastatic lesions, respectively. Computerized tomography of the chest, abdomen, and pelvis was unremarkable. Laboratory values were the following: na=140 meq/L, K=4.1 meq/L, cl=102 meq/L, co2=25 meq/L, BUn=21 mg/dL, cr=1.1 mg/dL, glu=71 mg/dL, hct=43.5%, PLt=143 × 109/L, Ptt=28.7 sec, and Pt=13.8 sec.

two large bore peripheral intravenous catheters (14- and 16-gauge) and a radial arterial line were inserted. he was pretreated with levoalbuterol for mild bronchitis and midazolam for anxiety. Patient tolerated induction and intubation without hemodynamic swings. octreotide 100 mcg was injected subcutaneously after intubation. Ciprofloxacin and metronidazole were administered for his penicillin drug allergy.

Arterial pressure fell abruptly to 43/26 mmhg 30 minutes after skin incision (figure 1). Manipulation of the tumor was stopped as fluid and intravenous

Fig. 1 Intraoperative hemodynamic measurements

M.E.J. ANESTH 22 (5), 2014

517Anesthetic considerAtions And MAnAgeMent of A PAtient with UnsUsPected cArcinoid crisis dUring hePAtic tUMor resection

octreotide (>450 mcg) were immediately administered to temporize the sudden drop in blood pressure and intermittent clamping of the hepatic artery to prevent the release of hepatic carcinoid mediators. no facial flushing or wheezing was noticed. Blood pressure was maintained with phenylephrine, ephedrine, and vasopressin boluses for refractory hypotension4.

After 4 hours of surgery, the oxygen saturation dropped gradually to 81% on the pulse oximeter. Because of concerns for pneumothorax from inadvertent diaphragmatic injury or venous air embolism5, the inspiratory oxygen concentration was increased from 50% to 100%. Ascultation of breath sounds were clear and pulmonary compliance on bag ventilation was adequate. Peak airway pressure and end-tidal carbon dioxide were unchanged. An arterial blood gas showed Paco2=39 mmhg and Pao2=459 mmhg. hypoperfusion secondary to blood loss could be a possibility that accounted for the low oxygen saturation, but it steadily improved as 2 units of packed red blood cells were transfused and more vasopressors given. estimated blood loss and urine output were 1-L and 1.8-L, respectively. A total of 2.5-L of 5% albumin and 5-L of crystalloid were infused. Patient was successfully extubated in stable condition with a post-transfusion hematocrit of 31%.

Discussion

currently the drug of choice for treatment of carcinoid syndrome is octreotide, a somatostatin analog that inhibits the release of vasoactive mediators6,7. the optimal dose for octreotide administered subcutaneously is 100 mcg before induction, or 25 mcg to 100 mcg intravenous boluses during surgery to achieve a desired effect8. other adjunct but obsolete therapies include antagonists that block specific

histamine (h1 and h2)3 and serotonin (5-ht2)

9,10 receptors, or bradykinin11 production. the effectiveness of these medications for preventing carcinoid crisis is inconclusive as studies have disputed their efficacy.

indirect adrenergic agonist (e.g., ephedrine) that causes catecholamine release is typically contraindicated because they worsen the mediator cascade. however, their role is unclear in preventing hypotension since ephedrine has been used in the intraoperative setting after octreotide therapy has failed12. on the other hand, direct adrenergic agonist (e.g., phenylephrine) and vasopressin, which acts on the V1 receptor, increase blood pressure by vasoconstriction of blood vessels are not involved in catecholamine release. therefore, both are useful drugs to prevent carcinoid hypotension.

while much emphasis is placed on the pharmacological strategies that target the pathophysiology of carcinoid syndrome, it underscores the perioperative considerations and its anesthetic implications. the key points in the management for this case include: (1) a complete preoperative assessment and optimization of electrolyte imbalance (e.g., hypokalemic hyperchloremic metabolic acidosis) from diarrhea before surgery13; (2) avoidance of medications that trigger allergic reactions or histamine release; (3) minimization of stress response that can release catecholamines during induction, intubation, and surgery14; (4) placement of an arterial line for monitoring rapid changes in blood pressure and blood draws for electrolytes, and large bore intravenous catheters, or even a central line, for infusion of blood and fluids; (5) availability of vasopressors and blood products in anticipation for hemodynamic instability and potential blood loss; and (6) good communication between the surgical and anesthesia team in case of emergency.

518 choi c. K.

References

1. Modlin iM, Sandor a: An analysis of 8305 cases of carcinoid tumors. Cancer; 1997, 79:813-29.

2. Farling Pa, durairaju ak: remifentanil and anaesthesia for carcinoid syndrome. Br J Anaesth; 2004, 92:893-5.

3. Vaughan dj, Brunner Md: Anesthesia for patients with carcinoid syndrome. Int Anesthesiol Clin; 1997, 35:129-42.

4. Cortinez F. li: refractory hypotension during carcinoid resection surgery. Anaesthesia; 2000, 55:505-6.

5. koo Bn, kil hk, Choi jS, kiM jY, Chun dh, hong YW: hepatic resection by the cavitron Ultrasonic surgical Aspirator increases the incidence and severity of venous air embolism. Anesth Analg; 2005, 101:966-70.

6. roY rC, Carter rF, Wright Pd: somatostatin, anaesthesia, and the carcinoid syndrome. Peri-operative administration of a somatostatin analogue to suppress carcinoid tumour activity. Anaesthesia; 1987, 42:627-32.

7. ParriS WC, oateS ja, kaMBaM j, ShMerling r, SaWYerS jF: Pre-treatment with somatostatin in the anaesthetic management of a patient with carcinoid syndrome. Can J Anaesth; 1988, 35:413-6.

8. dierdorF SF: carcinoid tumor and carcinoid syndrome. Curr Opin Anaesthesiol; 2003, 16:343-7.

9. MaSon ra, Steane Pa: Anaesthesia for a patient with carcinoid syndrome. Anaesthesia; 1976, 31:243-6.

10. SolareS g, BlanCo e, Pulgar S, diago C, raMoS F: carcinoid syndrome and intravenous cyproheptadine. Anaesthesia; 1987, 42:989-92.

11. Vaughan dj, hoWard jM, Brunner Md: refractory hypotension during carcinoid resection surgery. Anaesthesia; 2000, 55:927.

12. kinneY Ma, Warner Me, nagorneY dM, ruBin j, SChroeder dr, MaxSon PM, Warner Ma: Perianaesthetic risks and outcomes of abdominal surgery for metastatic carcinoid tumours. Br J Anaesth; 2001, 87:447-52.

13. kleine jW, khouW Yh, heereS Mg: hypovolemia and hypotension with carcinoid syndrome. Anesthesiology; 1978, 49:55. ManCuSo k, kaYe ad, Boudreaux jP, Fox Cj, lang P, 14. kalariCkal Pl, goMez S, PriMeaux Pj: carcinoid syndrome and perioperative anesthetic considerations. J Clin Anesth; 2011,23:329-41.

519 M.E.J. ANESTH 22 (5), 2014

UNUSUALLY DIFFICULT INTRAESOPHAGEAL BOUGIE INSERTION IN AN INTUBATED PEDIATRIC PATIENT

Xiaoyu Zhang* and Xuan Zhao**

Introduction

The insertion of an intraesophageal bougie has been a common step in hiatal repair procedures. This process is similar to insertion of a gastric tube (GT) in anesthetized, paralyzed, and intubated patients that can be difficult. We report an unusually difficult intraesophageal bougie insertion in an intubated pediatric patient owing to esophageal stricture.

Case Presentation

A 7-month-old male weighing 6.8 kg was scheduled for elective laparoscopic hiatal repair due to repetitive regurgitation. The patient had no past history of recent upper respiratory tract infection or deglutition difficulty. On physical examination, the patient had no anatomical throat variants other than malnutrition. Laboratory values were normal and an upper gastrointestinal contrast revealed the diagnosis of hiatal hernia (Fig. 1). Anesthesia was induced with atropine 0.5 mg, midazolam 0.5 mg, propofol 15 mg and remifentanil 5µg. After intravenous administration of cisatracurium, the patient was uneventfully intubated with an uncuffed armored tracheal tube (ID: 4.0 mm). Her direct laryngoscopic view was grade 1 according to the Cormack and Lehane classification with no pharynx and throat deformity. Anesthesia was maintained with sevoflurane and remifentanil. The patient received pressure-controlled ventilation with a peak inspiratory pressure of 20 cmH2O. The operation was otherwise uneventful. During the surgery, an intraesophageal bougie was requested to be inserted by a senior anesthesiologist in order to confirm proper wrap size and placement, as well as testing the security of the sutures holding the wrap in place. The placement of the intraesophageal bougie was attempted several times with no success. Various methods, including stiffening the bougie with ice water, using a guide wire, blind insertion of an endotracheal tube as an introducer, and direct laryngoscopy and assistance with Magill’s forceps, failed to advance the bougie tip more than 14 cm to 15 cm from incisor into esophageal. Considering the inherent risk of esophagogastric perforation associated with this maneuver, the surgeons decided to proceed with the repair and fundoplication without the aid of a bougie. Towards the end of the surgery, an attempt was made to insert a gastric tube to facilitate gastric emptying, but the tube

* MM ** MD Affiliation: Department of Anesthesiology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, 1665

Kongjiang Road, Shanghai, 200092, China. Corresponding author: Xuan Zhao, MD, Department of Anesthesiology, Xinhua Hospital, Shanghai Jiaotong University

School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China. Phone and Fax: +86 021 25078999. E-mail address: [email protected]

520 ZHAng X. et. al

could only be inserted around 15 cm and no stomach contents could be quilted from the tube. After tracheal extubation, the patient was shifted to the PICU, and in order to further decompress the stomach, insertion of a nasogastric tube into the esophagus was attempted under direct visualization using a pediatric flexible fiberoptic gastroscopy and guide wire. gastroscopy revealed confirmed an esophageal stricture located 15 cm from the incisors and a super slim endoscope with an outer diameter of 5 mm could not be pushed down owing to the stricture (Fig. 2). On follow-up in PICU, the child underwent a dilatation of the stricture by using a through-the-scope balloon (Fig. 3) and she was transferred to the ward on the 7th postoperative day in a healthy state.

Fig. 2 A super slim endoscope (outer diameter 5 mm) inserted until 15 cm from the incisors and could not be pushed down owing

to the stricture

Fig. 1 Preoperative upper gastrointestinal contrast revealed the

diagnosis of hiatal hernia

M.E.J. ANESTH 22 (5), 2014

521UNUSUALLY DIFFICULT INTRAESOPHAGEAL BOUGIE INSERTION IN AN INTUBATED PEDIATRIC PATIENT

Discussion

The use of an intraesophageal bougie has traditionally been an integral step in the repair of large hiatal hernia and fundoplication. Many times the passage of the bougie is not performed by the surgeon but rather by the anesthesiologist. This process is similar to insertion of a gastric tube (GT) in anesthetized, paralyzed, and intubated patients. The

piriform sinuses and the arytenoid cartilages are the most common sites of impaction during the insertion. Manipulations for improvement of insertion have included insertion of the bougiealong the posterior or lateral pharyngeal wall, flexion of the neck and application of lateral patient’s neck pressure1 or turning the head to one side1,2. Other techniques involve the use of direct laryngoscopy and assistance with Magill’s forceps, the use of a slit endotracheal tube, the use of a ureteral guidewire as a stylet, and the use of a gloved finger to steer the ngT after laryngeal impaction3-7. However, all of these techniques failed to advance the bougie through the esophagus in this patient because of the esophageal stricture. Pediatric esophageal stricture may occur following congenital esophageal atresia repair or as complications from reflux esophagitis, caustic ingestion, or restrictive Nissen fundoplication8. In this case, the patient had no past history of esophageal surgery, chemical injury or burns. Possible mechanisms include complication from reflux esophagitis, or esophageal tissue edema caused by intraoperative surgical injury.

Anesthetists should be aware of difficulties in inserting gastric tube or intraesophageal bougie in intubated patient, particularlyin pediatric patients with upper gastrointestinal disease, and because of impaired cognition, anatomical factors, complications of gastrointestinal disease, and difficult intubation Blind maneuvers for insertion of intraesophageal bongie can be traumatic and unreliable. Inadvertent intracranial introduction of a NG tube9, as well as cases of unintentional insertion of the NG tube into the trachea alongside a cuffed endotracheal tube, have been described10,11. A direct visualization technology can be used when insertion of a NG tube or intraesophageal bougie is necessary despite otherwise difficult conditions.

Fig. 3 The child underwent a dilatation of the stricture

by using a balloon

522 ZHAng X. et. al

References

1. Bong CL, Macachor JD, Hwang NC: Insertion of the nasogastric tube made easy. Anesthesiology; 2004, 101:266.

2. OZer S, Benumof JL: Oro-and nasogastric tube passage in intubated patients: fiberoptic description of where they go at the laryngeal level and how to make them enter the esophagus. Anesthesiology; 1999, 91:137-43.

3. Mahajan R, Gupta R: Another method to assist nasogastric tube insertion. Can J Anaesth; 2005, 52:652-3.

4. Flegar M, Ball A: Easier nasogastric tube insertion. Anaesthesia; 2004, 59:197.

5. Sprague DH, Carter SR: An alternative method for nasogastric tube insertion. Anesthesiology; 1980, 53:436.

6. Campbell B: A novel method of nasogastric tube insertion. Anaesthesia; 1997, 52:1234.

7. Appukutty J, Shroff PP: Nasogastric tube insertion using different techniques in anesthetized patients: a prospective, randomized study. Anesth Analg; 2009, 109:832-5.

8. Ball WS, Strife JL, RosenkrantZ J, et al: Esophageal strictures in children. Treatment by balloon dilatation. Radiology; 1984, 150:263-264.

9. Seebacher J, noZik D, Mathieu A: Inadvertent intracranial introduction of a nasogastric tube: a complication of severe maxillofacial trauma. Anesthesiology; 1975, 42:l00-2.

10. Sweatman AJ, Tomasello PA, Loughhead MG, et al: Misplacement of nasogastric tubes and oesophageal monitoring devices. Br J Anaesth; 1978, 50:389-92.

11. Saha AK: The insertion of nasogastric tubes in the anaesthetized patient. Anaesthesia; 1974, 29:367.

523 M.E.J. ANESTH 22 (5), 2014

LETTER TO THE EDITOR

SUCCESSFUL INTUBATION USING MCGRATH® MAC IN A PATIENT WITH TREACHER COLLINS SYNDROME

TakaToshi TsujimoTo*, saToshi Tanaka**, Yuki YoshiYama*, Yuki sugiYama*** and mikiTo kawamaTa****

Treacher Collins syndrome (TCS) is a congenital malformation of craniofacial development, which is associated with difficult tracheal intubation1. Several video laryngoscopes that have recently been developed have been shown to improve the laryngeal view in pediatric patients with difficult airways, including patients with TCS2-4. McGRATH® MAC (MAC; Aircraft Medical, Edinburgh, UK) has more recently been developed as a new video laryngoscope modified from McGRATH® Series 5 and may provide a better view of the glottis for intubation in adult patients5. However, there has been no report on the usefulness of MAC for intubation in pediatric patients with difficult airways.

A 13-year-old boy (146 cm; 36 kg) with TCS was scheduled for exotropia surgery under general anesthesia. Tetralogy of Fallot repair had been performed at the age of 4 years, when the trachea was intubated using a Macintosh laryngoscope despite Cormack-Lehane classification grade 3. At the age of 11 years, when mandibular distraction osteogenesis was performed, fiberoptic scope-guided endotracheal intubation was accomplished after failure of intubation using a Macintosh laryngoscope at a regional hospital. The patient showed the characteristic facial appearance of TCS such as micrognathia (Fig. 1-A). Thyromental and interincisor distances were 40 mm and 18 mm, respectively, showing moderate trismus. A magnetic resonance imaging scan revealed a relatively long distance from the mouth to the larynx (Fig. 1-B). Since we considered the airway to be patent in this patient under mask ventilation, general anesthesia was induced with 70 mg of propofol after setting up alternative devices to secure the airway, including equipment for percutaneous tracheostomy and a transtracheal jet ventilator. After mask ventilation has been successfully achieved, neuromuscular block was induced with 20 mg of rocuronium. In order to check the difficult airway in this patient, we used a Macintosh blade no. 3 and failed to visualize the epiglottis, defined as Cormack-Lehane classification grade 4. An attempt was then made to intubate using MAC with blade no. 3 (Fig. 1-C). The blade was easily inserted into the larynx and exposed the epiglottis and the vocal cord, defined as Cormack-Lehane classification grade 1. The trachea was successfully intubated with an ID 6.0 mm tracheal tube without difficulty.

* MD, Resident anesthesiologist.** MD, Assistant Professor.*** MD, Instructor.**** MD, Professor and Chairman. Affiliation: Department of Anesthesiology and Resuscitology, Shinshu University School of Medicine. Corresponding author: Dr. Mikito Kawamata, Department of Anesthesiology and Resuscitology, Shinshu University

School of Medicine, 3-1-1, Asahi, Matsumoto, Nagano 390-8621, JAPAN. Tel: +81-263-37-2670, Fax: +81-263-35-2734. E-mail: [email protected]

524 TSUJIMoTo T. et. al

Video-laryngoscopes such as the GlideScope®, Glidescope Cobalt® (Verathon Medical Inc., Bothell, WA, USA) and Pentax-Airway Scope ® (AWS; Hoya Co., Tokyo, Japan) have been reported to be useful for tracheal intubation in patients with difficult airways2-4. However, the usefulness of video laryngoscopes differs in patients with difficult airways, depending on features and severity of their anatomical abnormality in the oral cavity, pharynx and larynx6. Features of TCS include micrognathia, small mouth, high arched palate, cleft

palate and velopharyngeal incompetence, and tracheal intubation becomes difficult with advance of age1. In this patient, blade no. 3 of MAC could easily reach the larynx and visualize the glottis and vocal cord. This is probably because the shape of the blade of MAC fitted to the oropharyngeal features in this patient. Thus, the McGrath MAC may be useful for tracheal intubation in pediatric patients who have micrognathia and a small mouth as were seen in this patient.

Fig. 1(A) Lateral view of a 13-year-old boy with

Treacher Collins syndrome.(B) Sagittal magnetic resonance imaging

showed no abnormalities in the pharynx and larynx but revealed a relatively long distance from the mouth to the larynx. The curved dashed line traces the air passage from the incisor to the epiglottis. The length of the line is 120 mm.

(C) McGRATH® MAC with blade no. 3.

M.E.J. ANESTH 22 (5), 2014

525SUCCESSFUL INTUBATION USING MCGRATH® MAC IN A PATIENT WITH TREACHER COLLINS SYNDROME

References

1. hosking j, ZoaneTTi d, CarlYle a, anderson P, CosTi d: Anesthesia for Treacher Collins syndrome: a review of airway management in 240 pediatric cases. Pediatr Anesth; 2012, 22:752-8.

2. lee jh, Park Yh, BYon hj, han wk, kim hs, kim Cs, kim jT: A comparative trial of the GlideScope® video laryngoscope to direct laryngoscope in children with difficult direct laryngoscopy and an evaluation of the effect of blade size. Anesth Analg; 2013, 117:176-81.

3. iguChi h, sasano n, so m, hiraTe h, sasano h, kaTsuYa h: orotracheal intubation with an Airway Scope in a patient with Treacher Collins syndrome. J Anesth; 2008, 22:186-8.

4. ilies C, FudiCkar a, Thee C, düTsChke P, hanss r, doerges V, Bein

B: Airway management in pediatric patients using the Glidescope Cobalt®: a feasibility study. Minerva Anestesiol; 2012, 78:1019-25.

5. healY dw, maTies o, hoVord d, kheTerPal s: A systematic review of the role of videolaryngoscopy in successful orotracheal intubation. BMC Anesthesiol; 2012, 12:32. http://www.biomed-entral.com/ 1471-2253/12/32.

6. hYuga s, sekiguChi T, ishida T, YamamoTo k, sugiYama Y, kawamaTa m: Successful tracheal intubation with the McGrath® MAC video laryngoscope after failure with the Pentax-AWS™ in a patient with cervical spine immobilization. Can J Anaesth; 2012, 59:1154-5.

527 M.E.J. ANESTH 22 (5), 2014

CORRESPONDENCE

AnesthesiA CAre Providers’ BAsed interdisCiPlinAry Peri-oPerAtive Cross-over Post-MArket - sAfety-

surveillAnCe: is it futuristiC PAtient sAfety ideA? running title: Post-hire PMss

for interventionists

Deepak Gupta*

education and practice of medicine potentially provides an unexplored avenue for anesthesia care providers wherein currently practiced anesthesia care providers’ initiated quality-assurance (QA) can grow out of the bounds of peri-anesthesia events. these QA processes should expand into anesthesia care providers’ based interdisciplinary peri-operative cross-over post-market (post-hire) safety surveillance (PMss) as similar to PMss for devices1 and drugs2. Anesthesia care providers witness plethora of surgical interventions, multiple ways of performing same interventions and comparative peri-operative variability across surgical operators. hence, their understanding of peri-operative outcomes with system- and operator-based risk factors can guide them to generate a local and indigenous rating system for operators that guide (a) the operators themselves, (b) their supervisory administrators, and (c) their paying patients to make appropriate decisions wherein consequently (a) the operators are given procedure-specific privileges based on their personal understanding of their limitations, (b) the administrators’ decisions are guided by statistical analysis of local peri-operative outcomes and (c) the patients’ shopping capabilities are enhanced by transparent local ratings of the operators’ procedures-specific proficiency.

the cross-over will be the operators themselves preempting similar avenues for the administrators who may decide against blanket privileges3 for the anesthesia care providers who themselves by default are practitioners of procedural medicine. this PMss will not mean an excuse for letting go personnel but healthcare-generated wealth will be re-distributed according to the health care providers’ proficiency as adjudged by local patient outcomes. Redistribution according to dynamics of allowable and restricted procedure-related privileges will ensure each interventionist gets his/her share without losing his/her elite economic status in the society. The secondary benefit will be that the rising incomes of proficient proceduralists will inspire peer practitioners to either accept their limited access to perform procedures or improve their proficiency to target top end elite salaries4-5.

* Md. Affiliation: Department of Anesthesiology, Wayne State University/Detroit Medical Center, Detroit, Michigan, United States. Corresponding author: dr. deepak gupta, Box. no. 162, 3990 John r. detroit, Mi 48201, united states. tel: 1-313-745-

7233, fax: 1-313-993-3889. e-mail: [email protected]

528 guPtA d.

the new PMss will be asking simple questions to the anesthesia care providers that whether they would want the particular operative procedures performed upon them or their next of kin by operators being rated. Analogously, the operators would be asked whether they would want specific anesthesia procedures and specific practice of anesthesia provided to them or to their next of kin or to their patients by anesthesia care providers being rated. though the documentation of interventionists’ rating per procedure will be a three-pronged question “Definitely-Not Sure-never” and the cumulative datasheets generated will reflect percentages per rated procedure for the interventionists, these comprehensive datasheets will be restricted for limited personal as well as in-house management. however, the selective datasheets that reflects only the proficiency “Definitely” data (and not the deficiency “Never” data) of rated interventionists will be shared with the future patients who will have electively decided to undergo the rated procedure at the rating health institution, and will need in-house informational support in terms of health institution’s local rating systems of its interventionists.

Although in-house QA processes already exist, the perceptive positive reinforcements (“i prefer this interventionist for me and/or my next of kin” instead of “i do not prefer this interventionist for me and/or my next of kin”) from these in-house processes will be able to percolate into the awareness of future patients who are coming for elective interventions. Moreover, compared to lay persons, the educated peers would be better guides for the prospective patients so that they can make informed decisions based on their choices as well as the urgencies of their clinical situations where-in deciding for/against the rated operating interventionist is an immense question for the patients.

When evaluating a care-giving system where focus is only on prevention of mortality, that system is apparently visualizing only the tip of iceberg. the iceberg of patient safety is constituted of unappreciated or under-reported morbidities that can be easily quantified by continual QA/PMss processes with potential corrections/preventions by pre-emptive re-allocation and re-organization of the locally and objectively peer-rated interventionists’ teams in question. hence, the sole aim of this PMss will be to ensure constant

vigilance and regular review about procedure-specific privileges based on patient outcomes secondary to mortality and morbidity as well as supporting medical staff’s perceived outcomes secondary to near-hits-near-misses so that the operators (including anesthesia care providers) can themselves find their niche in any of the following: (a) blanket clinical privileges (b) restricted procedure-specific privileges (c) academics (d) research (e) administration-management6. this will ensure that the providers’ remunerations do not cease but the proportions of avenues (clinical privilege based, experience and seniority based, local patient outcome based, academics based, research based, and managerial based avenues) generating these reimbursements are safer for the patients, the administrators as well as the operators wherein clinical interventions involving the major risks for patient safety are only performed by the interventionists proficient in those areas as adjudged by the continual QA/PMss processes whereas not-so-safe proceduralists can primarily focus on other avenues as well as interventions that involve only minor risks for patient safety.

the local ratings system cannot be anonymous to avoid the appeasing traits of the inter-dependent peers as well as to ensure that the PMss raters stand by their ratings performed daily with each patient encounter/procedure performed by the rated operators. Another avenue as a direct result of this PMss process is that there will be a need for creating transient phase of provisional restrictions to blanket privileges. the interventionists will be allocated to the transient phase when they will be learning new techniques or adjusting their old techniques to timely improve their worsening outcomes/ratings. similarly, the permanent restrictions to blanket privileges will not mean that these restrictions cannot be overturned depending on the vigor of the rated interventionist who is ready to learn and improvise. this arrangement will always be dynamic because PMss process will not be meant for vindications but to honestly aim at preemptively acting in response to personal failures that, if overlooked, can affect the patient safety outcomes.

every process (including PMss) will always have a paradox of an eventual slippery slope. however, the intentions are clean and honest so that base salaries and base stature of interventionists will not change; and only

M.E.J. ANESTH 22 (5), 2014

529AnesthesiA CAre Providers’ BAsed interdisCiPlinAry Peri-oPerAtive Cross-over Post-MArket- sAfety-surveillAnCe: is it futuristiC PAtient sAfety ideA?running title: Post-hire PMss for interventionists

the transcendental salaries will be at constant dynamic adjustment pathways according to the interventionists’ prowess and proficiency for the procedures as well as their results and patient outcomes. the rating systems will ensure that the salary adjustments are transparent without any malign. in summary, analogous to PMss for drugs and devices, the novice application will

ensure post-hire PMss for operators/interventionists by interdisciplinary peers who will apply lay persons’ understanding, interpretations and sensibilities but will possess more than just lay persons’ experience in regards to medical knowledge, clinical skills, communication skills, decision-making capacity and professionalism when rating an interventionist.

530 guPtA d.

References

1. fdA.gov http://www.fda.gov/ Medicaldevices/ safety/CdrhP ostmarketsurveillance/default.htm Accessed on March 26, 2014.

2. fdA.gov http://www.fda.gov/drugs/guidancecomplianceregulatory information/surveillance/ucm204091.htm Accessed on March 26, 2014.

3. Barash pG, Cullen BF, stoeltinG rk, Cahalan Mk, stoCk MC, orteGa r (eDs): handbook of clinical anesthesia 7th edition, Ch. 2, Wolters Kluwer Health/Lippincott Williams &Wilkins, Philadelphia 2013.

4. Medscape.com http://www.medscape.com/features/slideshow/compensation/2013/anesthesiology Accessed on March 26, 2014.

5. MaCintyre p, stevens B, Collins s, hewer i: Cost of education and earning potential for non-physician anesthesia providers. AANA J; 82:25-31, 2014.

6. reiCh Dl, Galati M, krol M, BoDian Ca, kahn ra: A mission-based productivity compensation model for an academic anesthesiology department. Anesth Analg; 2008, 107:1981-8.

middle east journal of anesthesiology · 2018-10-24 · 443..j. n 22 5, 2014 middle east journal of...

Documents