Abstract
Purpose
To review the current literature and generate recommendations on the role of newer technology in the management of the unanticipated difficult airway.
Methods
A literature search using key words and filters of English language and English abstracted publications from 1990–96 contained in theMedline, Current Contents andBiological Abstracts databases was carried out. The literature was reviewed and condensed and a series of evidence-based recommendations were evolved.
Conclusions
The unanticipated difficult airway occurs with a low but consistent incidence in anaesthesia practice. Difficult direct laryngoscopy occurs in 1.5–8.5% of general anaesthetics and difficult intubation occurs with a similar incidence. Failed inubation occurs in 0.13–0.3% general anaesthetics. Current techniques for predicting difficulty with laryngoscopy and intubation are sensitive, non-specific and have a low positive predictive value. Assessment techniques which utilize multiple characteristics to derive a risk factor tend to be more accurate predictors. Devices such as the laryngeal mask, lighted stylet and rigid fibreoptic laryngoscopes, in the setting of unanticipated difficult airway, are effective in establishing a patent airway, may reduce morbidity and are occasionally lifesaving. Evidence supports their use in this setting as either alternatives to facemask and bag ventilation, when it is inadequate to support oxygenation, or to the direct laryngoscope, when trachéal intubation has failed. Specifically, the laryngeal mask and Combitube™ have proved to be effective in establishing and maintaining a patent airway in “cannot ventilate” situations. The lighted stylet and Bullard (rigid) fibreoptic scope are effective in many instances where the direct laryngoscope has failed to facilitate trachéal intubation. The data also support integration of these devices into strategies to manage difficult airway as the new standard of care. Training programmes should ensure graduate physicians are trained in the use of these alternatives. Continuing medical education courses should allow physicians in practice the opportunity to train with these alternative devices.
Résumé
Objectif
Passer en revue la documentation courante et fournir des recommandations sur le rôle de la nou velle technologie dans la conduite à tenir lors d’une intubation difficile.
Méthodes
On a procédé à une recherche documentaire selon des mots-clés et des filtres de langue anglaise et des publications de résumés anglais de 1990 à 1996, contenus dans les bases de données deMedline, Current Contents etBiological Abstracts. La littérature a été revue et résumée et une série de recommandations basées sur les faits ont été élaborées.
Conclusion
Les difficultés d’intubation non prévues surviennent selon une incidence faible, mais constante, dans la pratique de l’anesthésie. Des problèmes de laryngoscopie directe et des difficultés d’intubation ont lieu dans 1,5–8,5 % des anesthésies générales. Léchéc de l’intubation survient dans 0,13–0,3 % des anesthésies générales. Les techniques habituelles de prédiction des difficultés de laryngoscopie et d’intubation sont sensibles, mais non spécifiques et ont une faible valeur prédictive. Des techniques d’évaluation qui utilisent plusieurs caractéristiques pour en déduire un facteur de risque ont généralement de meilleures qualités prédictives. Lors d’une intubation difficile inattendue, des appareils comme le masque laryngé, le stylet lumineux et le laryngoscope fibroscopique rigide sont efficaces dans le rétablissement de la perméabilité des voies aériennes, ils peuvent réduire la morbidité et peuvent parfois sauver des vies. Lexpérience encourage leur emploi en remplacement du masque et de la ventilation manuelle quand la ventilation assistée est inappropriée, ou à la place du laryngoscope direct quand l’intubation endotrachéale a été un échec. Le masque laryngé et le Combitube® ont été spécialement efficaces dans le rétablissement et le maintien de la perméabilité des voies aériennes, dans les situations où l’on ne peut ventiler. Le stylet lumineux et le fibroscope rigide Bullard réussissent souvent à faciliter l’intubation endotrachéale quand le laryngoscope direct a échoué. Les données favorisent également l’intégration de ces dispositifs, considérée comme le nouveau standard de soins, dans la démarche à suivre lors de l’intubation difficile. Les programmes de formation devraient garantir que les médecins diplômés soient familiarisés avec l’usage de ces solutions de remplacement. L’éducation médicale continue devrait donner aux praticiens l’occasion d’apprendre à utiliser ces dispositifs.
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References
Caplan RA, Benumof JL, Berry FA, et al. Practice guidelines for management of the difficult airway. A report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology 1993; 78: 597–602.
Goldbloom R, Battista RN. The periodic health examination: 1. Introduction. Can Med Assoc J 1986; 134: 721–3.
Sackett DL. Rules of evidence and clinical recommendations on use of antithrombotic agents. Chest 1989; 95: 2S-4S.
Cormack RS, Lehane J. Difficult tracheal intubation in obstetrics. Anaesthesia 1984; 39: 1105–11.
Rose DK, Cohen MM. The airway: problems and predictions in 18,500 patients. Can J Anaesth 1994; 41: 372–83.
Rocke DA, Murray WB, Rout CC, Gouws E. Relative risk analysis of factors associated with difficult intubation in obstetric anesthesia. Anesthesiology 1992; 77: 67–73.
Rose DK, Cohen MM. The incidence of airway problems depends on the definition used. Can J Anaesth 1996; 43: 30–4.
Rose DK, Cohen MM. Predicting difficult laryngoscopy. (Reply) Can J Anaesth 1996; 43: 1082.
Davis KR. Does physical exam predict difficulty with intubation? Anesth Analg 1994; 78: S84.
El-Gtmzouri AR, McCarthy RJ, Tuman KJ, Tanck EN, Ivankovich AD. Preoperative airway assessment: predictive value of a multivariate risk index. Anesth Analg 1996; 82: 1197–204.
Dhaliwal AS, Tinnell CA, Palmer SK. Difficulties encountered in airway management: a review of 15,616 general anesthetics at a university medical center. Anesth Analg 1996; 82: S92.
Mallampati SR, Gatt SP, Gugino LD, et al. A clinical sign to predict difficult tracheal intubation: a prospective study. Can Anaesth Soc J 1985; 32: 429–34.
Samsoon GLT, Young JRB. Difficult tracheal intubation: a retrospective study. Anaesthesia 1987; 42: 487–90.
Tham EJ, Gildersleve CD, Sanders LD, Mapleson WW, Vaughan RS. Effects of posture, phonation and observer on Mallampati classification. Br J Anaesth 1992; 68: 32–8.
Wilson ME, Spiegelhalter D, Robertson JA, Lesser RP. Predicting difficult intubation. Br J Anaesth 1988; 61: 211–6.
Savva D. Prediction of difficult tracheal intubation. Br J Anaesth 1994; 73: 149–53.
Ramadhani SAL, Mohamed LA, Rocke DA, Gouws E. Sternomental distance as the sole predictor of difficult laryngoscopy in obstetric anaesthesia. Br J Anaesth 1996; 77: 312–6.
Tse JC, Rimm EB, Hussain A. Predicting difficult intubation in surgical patients scheduled for general anesthesia: a prospective blind study. Anesth Analg 1995; 81: 254–8.
Yamamato K, Tsubkawa T, Shibata K, Ohmura S, Nitta S, Kobayashi T. Predicting difficult intubation with indirect laryngoscopy. Anesthesiology 1997; 86: 316–21.
Butler PJ, Dhara SS. Prediction of difficult laryngoscopy: an assessment of the thyromental distance and Mallampati predictive tests. Anaesth Intensive Care 1992; 20: 139–42.
Lewis M, Keramati S, Benumof JL, Berry CC. What is the best way to determine oropharyngeal classification and mandibular space length to predict difficult laryngoscopy? Anesthesiology 1994; 81: 69–75.
Karkouti K, Rose DK, Ferris LE, Wigglesworth DF, Meisami-Fard T, Lee H. Inter-observer reliability of ten tests used for predicting difficult tracheal intubation. Can J Anaesth 1996; 43: 554–9.
Benumof JL, Cooper SD. Quantitative improvement in laryngoscopic view by optimal external laryngcal manipulation. J Clin Anesth 1996; 8: 136–40.
Takahata O, Kubota M, Mamiya K, et al. The efficacy of the “BURP” maneuver during a difficult laryngoscopy. Anesth Analg 1997; 84: 419–21.
Caplan RA, Posner KL, Ward RJ, Cheney W. Adverse respiratory events in anesthesia: a closed claims analysis. Anesthesiology 1990; 72: 828–33.
Kidd JF, Dyson A, Latto IP. Successful difficult intubation. Use of the gum elastic bougie. Anaesthesia 1988; 43: 437–8.
Dogra S, Falconer R, Latto IP. Successful difficult intubation. Tracheal tube placement over a gum-elastic bougie. Anaesthesia 1990; 45: 774–6.
Nolan JP, Wilson ME. Orotracheal intubation in patients with potential cervical spine injuries. An indication for the gum elastic bougie. Anaesthesia 1993; 48: 630–3.
Uchida T, Hikawa Y, Saito Y, Yasuda K. The McCoy levering laryngoscope in patients with limited neck extension. Can J Anaesth 1997; 44: 674–6.
Laurent SC, de Melo AE, Alexander-Williams JM. The use of the McCoy laryngoscope in patients with simulated cervical spine injuries. Anaesthesia 1996; 51: 74–5.
Gabbott DA. Laryngoscopy using the McCoy laryngoscope after application of a cervical collar. Anaesthesia 1996; 51: 812–4.
Holland R, Webb RK, Runcimtm WB. Oesophageal intubation: an analysis of 2000 incident reports. Anaesth Intensive Care 1993; 21: 608–10.
Brain AIJ. The laryngeal mask — a new concept in airway management. Br J Anaesth 1983; 55: 801–4.
Verghese C, Brimacombe JR. Survey of laryngeal mask airway usage in 11,910 patients: safety and efficacy for conventional and nonconventional usage. Anesth Analg 1996; 82: 129–33.
Mahiou P, Narchi P, Veyrac P, Germond M, Gory G, Bazin G. Is laryngeal mask easy to use in case of difficult intubation? Anesthesiology 1992; 77: A1228.
Brimacombe J, Berry A. The laryngeal mask airway — the first ten years. Anaesth Intensive Care 1993; 21: 225–6.
Christian AS. Failed obstetric intubation (Letter). Anaesthesia 1990; 45: 995.
Hasham FM, Andrews PJD, Juneja MM, Ackerman WE III. The laryngeal mask airway facilitates intubation at cesarean section. A case report of difficult intubation. Int J Obstet Anesth 1993; 2: 181–2.
McClune S, Regan M, Moore J. Laryngeal mask airway for Caesarean section. Anaesthesia 1990; 45: 227–8.
McFarlane C. Failed intubation in the obese obstetric patient and the laryngeal mask. Int J Obstet Anesth 1993; 2: 183–5.
Storey J. The laryngeal mask for failed intubation at Caesarean section. Anaesth Intensive Care 1992; 20: 118–9.
King TA, Adams AP. Failed tracheal intubation. Br J Anaesth 1990; 65: 400–14.
Smith I, White PF. Use of the laryngeal mask airway as an alternative to a face mask during outpatient arthroscopy. Anesthesiology 1992; 77: 850–5.
Chadwick IS, Vohra A. Anaesthesia for emergency Caesarean section using the Brain laryngeal airway. Anaesthesia 1989; 44: 261–2.
Priscu V, Prism L, Soroker D. Laryngeal mask for failed intubation in emergency Caesarean section (Letter). Can J Anaesth 1992; 39: 893–6.
Rabey PG, Murphy PJ, Langton JA, Barker P, Rowbotham DJ. Effect of the laryngeal mask airway on lower oesophageal sphincter pressure in patients during general anaesthesia. Br J Anaesth 1992; 69: 346–8.
Brimacombe JR, Berry AM. Cricoid pressure. Can J Anaesth 1997; 44: 414–25.
Ansermino JM, Blogg CE. Cricoid pressure may prevent insertion of the laryngeal mask airway. Br J Anaesth 1992; 69: 465–7.
Asai T, Barclay K, Power I, Vaughan RS. Cricoid pressure impedes placement of the laryngeal mask airway and subsequent tracheal intubation through the mask. Br J Anaesth 1994; 72: 47–51.
Heath ML, Allagain J. Intubation through the laryngeal mask. A technique for unexpected difficult intubation. Anaesthesia 1991; 46: 545–8.
Strang TI. Does the laryngeal mask airway compromise cricoid pressure? Anaesthesia 1992; 47: 829–31.
Asai T, Barclay K, Power I, Vaughan RS. Cricoid pressure impedes placement of the laryngeal mask airway. Br J Anaesth 1995; 74: 521–25.
Gabbott DA, Sasada MR. Laryngeal mask airway insertion using cricoid pressure and manual in-line neck stabilisation. Anaesthesia 1995; 50: 674–6.
Brimacombe JR, Berry A. Mechanical airway obstruction after cricoid pressure with the laryngeal mask airway (Letter). Anesth Analg 1994; 78: 604–5.
Allman KG. The effect of cricoid pressure application on airway patency. J Clin Anesth 1995; 7: 197–9.
Brimacombe J. Cricoid pressure and the laryngeal mask airway (Letter). Anaesthesia 1991; 46: 986–7.
Brimacombe J, Berry A, White A. An algorithm for use of the laryngeal mask airway during failed intubation in the patient with a full stomach (Letter). Anesth Analg 1993; 77: 398–9.
Allison A, McCrory J. Tracheal placement of a gum elastic bougie using the laryngeal mask airway (Letter). Anaesthesia 1990; 45: 419–20.
Brimacombe J, Berry A. The laryngeal mask airway for obstetric anesthesia and neonatal resuscitation. Int J Obstet Anesth 1994; 3: 211–8.
Frass M, Frenzer R, Rauscha F, Weber H, Packer H, Leithner C. Evaluation of esophageal tracheal combitube in cardiopulmonary resuscitation. Crit Care Med 1986; 15: 609–11.
Frass M, Frenzer R, Zahler J, Ilias W, Leithner C. Ventilation via the esophageal tracheal combitube in a case of difficult intubation. J Cardiothorac Anesth 1987; 1: 565–8.
Frass M, Frenzer R, Mayer G, Popovic R, Leithner C. Mechanical ventilation with the esophageal tracheal combitube (ETC) in the intensive care unit. Arch Emerg Med 1987; 4: 219–25.
Rumball CJ, MacDonald D. The PTL, Combitube, laryngeal mask, and oral airway: a randomized prehospital comparative study of ventilatory device effectiveness and cost-effectiveness in 470 cases of cardiorespiratory arrest. Prehosp Emerg Care 1997; 1: 1–10.
Klein H, Williamson M, Sue-Ling HM, Vucevic M, Quinn AC. Esophageal rupture associated with the Combitube™. Anesth Analg 1997; 85: 937–9.
Johnson C, Hunter J, Ho E, Bruff C. Fibreoptic intubation facilitated by a rigid laryngoscope (Letter). Anesth Analg 1991; 72: 714.
Russell SH, Hirsch NP. Simultaneous use of two laryngoscopes. (Letter) Anaesthesia 1993; 48: 918.
Bjoraker DG. The Bullard intubating laryngoscopes. Anesthesiology Review 1990; 17: 64–70.
Dyson A, Harris J, Bhatia K. Rapidity and accuracy of tracheal intubation in a mannequin: comparison of the fibreoptic with the Bullard laryngoscope. Br J Anaesth 1990; 65: 268–70.
Saunders PR, Geisecke AH. Clinical assessment of the adult bullard laryngoscope. Can J Anaesth 1989; 36: S118–9.
Gorback MS. Management of the challenging airway with the Bullard laryngoscope. J Clin Anesth 1991; 3: 473–7.
Cohn AI, Hart RT, McGraw SR, Blass NH. The Bullard laryngsocope for emergency airway management in a morbidly obese parturient. Anesth Analg 1995; 81: 872–3.
Cohn AI, McGraw SR, King WH. Awake intubation of the adult trachea using the Bullard laryngoscope. Can J Anaesth 1995; 42: 246–8.
Cooper SD, Benumof JL, Ozaki GT. Evaluation of the Bullard laryngoscope using the new intubating stylet: comparison with conventional laryngoscopy. Anesth Analg 1994; 79: 965–70.
Crosby ET. Techniques using the Bullard laryngoscope (Letter). Anesth Analg 1995; 81: 1314–5.
Mendel P, Bristow A. Anaesthesia for procedures on the larynx and pharynx. The use of the Bullard laryngoscope in conjunction with high frequency jet ventilation. Anaesthesia 1993; 48: 263–5.
Hastings RH, Vigil AC, Hanno R, Yang B-Y, Sartoris DJ. Cervical spine movement during laryngoscopy with the Bullard, Macintosh and Miller laryngoscopes. Anesthesiology 1995; 82: 859–69.
Hung OR, Stewart RD. Lightwand intubation: I — A new lightwand device. Can J Anaesth 1995; 42: 820–5.
Hung OR, Pytka S, Morris I, Murphy M, Stewart RD. Lightwand intubation: II. Clinical trial of a new lightwand for tracheal intubation in patients with difficult airways. Can J Anaesth 1995; 42: 826–30.
Hung OR, Al-Qatari M. Light-guided retrograde intubation. Can J Anaesth 1997; 44: 877–82.
Asai T, Latto IP. Use of the lighted stylet for tracheal intubation via the laryngeal mask airway (Letter). Br J Anaesth 1995; 75: 503–4.
Morris IR. Fibreoptic intubation. Can J Anaesth 1994; 41: 996–1008.
Benumof JL, Schelller MS. The importance of transtracheal jet ventilation in the management of the difficult airway. Anesthesiology 1989; 71: 769–78.
King H-K, Wang L-F, Khan AK, Wooten DJ. Translaryngeal guided intubation for difficult intubation. Crit Care Med 1987; 15: 869–71.
Barriot P, Riou B. Retrograde technique for tracheal intubation in trauma patients. Crit Care Med 1988; 16: 712–3.
Bissinger U, Guggenberger H, Lenz G. Retrogradeguided fiberoptic intubation in patients with laryngeal carcinoma. Anesth Analg 1995; 81: 408–10.
Burkey B, Escalamado R, Morganroth M. The role of cricothyrotomy in airway management. Clin Chest Med 1991; 12: 561–71.
Metz S, Parmet JL, Levitt JD. Failed emergency transtracheal ventilation through a 14-gauge intravenous catheter. J Clin Anesth 1996; 8: 58–62.
Poterack KA. Emergency transtracheal jet ventilation: review of cases via the internet. Anesth Analg 1995; 80: S379.
Hill RS, Koltai PJ, Farnes SM. Airway complications from laryngoscopy and panendoscopy. Ann Otol Rhinol Laryngol 1987; 96: 691–4.
Mathew JP, Rosenbaum SH, O’Connor T, Barash PG. Emergency trachéal intubation in the postanesthesia care unit: physician error or patient disease? Anesth Analg 1990; 71: 691–7.
Rose DK, Cohen MM, Wigglesworth DF, DeBoer DP. Critical respiratory events in the postanesthesia care unit. Anesthesiology 1994; 81: 410–8.
Lee PJ, O’Reilly M, Tremper K, Naughton N. An analysis of reintubations from a quality assurance database of 47,000 cases. Anesth Analg 1996; 82: S270.
Dellinger RP. Fiberoptic bronchoscopy in adult airway management. Crit Care Med 1990; 18: 882–7.
Bedger RC Jr, Chang J-L. A jet-stylet endotracheal catheter for difficult airway management. Anesthesiology 1987; 66: 221–3.
Benumof JL. Additional safety measures when changing endotracheal tubes (Letter). Anesthesiology 1991; 75: 921–2.
Cooper RM: The use of an endotracheal ventilation catheter in the management of difficult extubations. Can J Anaesth 1996; 43: 90–3.
Cooper RM. Extubation and changing endotracheal tubes.In: Benumof JL (Ed.). Airway Management: Principles and Practice. St. Louis: Mosby-Year Book, 1996: 864–85.
Davies JM, Weeks S, Crone LA, Paulin E. Difficult intubation in the parturient. Can J Anaesth 1989; 36: 668–74.
Lyons G. Failed intubation. Six years’ experience in a teaching maternity unit. Anaesthesia 1985; 40: 759–62.
Lyons G, MacDonald R. Difficult intubation in obstetrics (Letter). Anaesthesia 1985; 40: 1016.
Högberg U. Maternal deaths in Sweden, 1971–1980. Acta Obstet Gynecol Scand 1986; 65: 161–7.
Hawthorne L, Wilson R, Lyons G, Dresner M. Failed intubation revisited: 17-yr experience in a teaching maternity unit. Br J Anaesth 1996; 76: 680–4.
Pilkington S, Carli F, Dakin MJ, et al. Increase in Mallampati score during pregnancy. Br J Anaesth 1995; 74: 638–42.
Morgan M. The confidential enquiry into maternal deaths (Editorial). Anaesthesia 1986; 41: 689–91.
Garnie JC, Street MK, Kumar B. Emergency intubation of the trachea facilitated by suxamethonium. Observations in obstetric and general surgical patients. Br J Anaesth 1986; 8: 498–501.
Dewan D. Obesity.In: Chestnut DH (Ed.). Obstetric Anesthesia: Principles and Practice. St. Louis: Mosby,; 1994: 942–55.
Writer D. Hypertensive disorders.In: Chestnut DH (Ed.). Obstetric Anesthesia: Principles and Practice. St. Louis: Mosby, 1994: 846–82.
Farcon EL, Kim MH, Marx GF. Changing Mallampati score during labour. Can J Anaesth 1994; 41: 50–1.
Jouppila R, Jouppila P, Hollmén A. Laryngeal oedema as an obstetric anaesthesia complication. Case reports. Acta Anaesthesiol Scand 1980; 24: 97–8.
Creighton RE. The infant airway (Editorial). Can J Anaesth 1994; 41: 174–6.
Jones AEP, Pelton DA. An index of syndromes and their anaesthetic implications. Can Anaesth Soc J 1976; 23: 207–26.
Inada T, Fujise K, Tachibana K, Shingu K. Orotracheal intubation through the laryngeal mask airway in paediatric patients with Treacher-Collins syndrome. Paed Anaesth 1995; 5: 129–32.
Baraka A. Laryngeal mask airway for resuscitation of a newborn with Pierre-Robin syndrome (Letter). Anesthesiology 1995; 83: 645–6.
Nath G, Major V. The laryngeal mask airway in the management of a paediatric difficult airway. Anaesth Intensive Care 1992; 20: 518–20.
Mason DG, Bingham RM. The laryngeal mask airway in children. Anaesthesia 1990; 45: 760–3.
Mizushima A, Wardall GJ, Simpson DL. The laryngeal mask airway in infants. Anaesthesia 1992; 47: 849–51.
Paterson SJ, Byrne PJ, Molesky MG, Seal RF, Finucane BT. Neonatal resuscitation using the laryngeal mask airway. Anesthesiology 1994; 80: 1248–53.
Holzman RS, Nargozian CD, Florence FB. Lightwand intubation in children with abnormal upper airways. Anesthesiology 1988; 69: 784–7.
Krucylak CP, Schreiner MS. Orotracheal intubation of an infant with hemifacial microsomia using a modified lighted stylet. Anesthesiology 1992; 77: 826–7.
Fisher QA, Tunkel DE. Lightwand intubation of infants and children. J Clin Anesth 1997; 9: 275–9.
Wheeler M, Ovassapian A. Pédiatric fiberoptic intubation.In: Ovassapian A (Ed.). Fiberoptic Endoscopy and the Difficult Airway, 2nd ed. New York: Lippincott-Raven, 1996: 105.
Berthelsen P, Prytz S, Jacobsen E. Two-stage fiberoptic nasotracheal intubation in infants: a new approach to difficult pédiatric intubation. Anesthesiology 1985; 63: 457–8.
Hemmer D, Lee TS, Wright BD. Intubation of a child with a cervical spine injury with the aid of a fiberoptic bronchoscope. Anaesth Intensive Care 1982; 10: 163–5.
Borland LM, Casselbrandt M. The Bullard laryngoscope. A new indirect oral laryngoscope (pediatric version). Anesth Analg 1990; 70: 105–8.
Shulman GB, Connelly NR, Gibson C. The adult Bullard laryngoscope in paediatric patients. Can J Anaesth 1997; 44: 969–72.
Cooper CMS, Murray-Wilson A. Retrograde intubation. Management of a 4.8-kg, 5-month infant. Anaesthesia 1987; 42: 1197–200.
Audenaert SM, Montgomery CL, Stone B, Akins RE, Lock RL. Retrograde-assisted fiberoptic tracheal intubation in children with difficult airways. Anesth Analg 1991; 73: 660–4.
Borland LM, Swan DM, Leff S. Difficult pédiatric endotracheal intubation: a new approach to the retrograde technique. Anesthesiology 1981; 55: 577–8.
Ravussin P, Bayer-Berger M, Monnier P, Savary M, Freeman J. Percutaneous transtracheal ventilation for laser endoscopie procedures in infants and small children with laryngeal obstruction: report of two cases. Can J Anaesth 1987; 34: 83–6.
Mark L, Schauble J, Gibby G, Drake J, Turley S. Effective dissemination of critical airway information: the Medical Alert* National Difficult Airway/Intubation Registry.In: Benumof JL (Ed.). Airway Management: Principles and Practice. St. Louis: Mosby-Year Book, 1995: 931–43.
Kopacz DJ, Neal JM, Pollock JE. The regional anesthesia “learning curve”. What is the minimum number of epidural and spinal blocks to reach consistency? Reg Anesth 1996; 21: 182–90.
Mason RA. Learning fibreoptic intubation: fundamental problems (Editorial). Anaesthesia 1992; 47: 729–31.
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Funding for this project was provided by die following: Cook Canada Inc; Dr. André DesMarais; Laerdal Canada; the Laryngeal Mask Airway Company; Organon Canada Ltd.; Vitaid.
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Crosby, E.T., Cooper, R.M., Douglas, M.J. et al. The unanticipated difficult airway with recommendations for management. Can J Anaesth 45, 757–776 (1998). https://doi.org/10.1007/BF03012147
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DOI: https://doi.org/10.1007/BF03012147