The difficult airway in adults
- Ron M Walls, MD, FRCPC, FAAEM
Ron M Walls, MD, FRCPC, FAAEM
- Editor-in-Chief — Adult and Pediatric Emergency Medicine
- Section Editor — Adult Resuscitation
- Professor of Medicine
- Harvard Medical School
- Brigham and Women's Hospital
- Michael F Murphy, MD, FRCPC
Michael F Murphy, MD, FRCPC
- Professor and Chair of Anesthesia and Pain Medicine
- University of Alberta
Most emergency department (ED) endotracheal intubations are performed on an emergent basis (ie, intubation cannot be delayed or avoided). The universal emergency airway management algorithm© provides the recommended approach to emergency intubation (algorithm 1 and algorithm 2) [1,2]. This approach is based on two key assessments of the patient prior to intubation.
The first assessment is to determine if the patient has a "crash" airway (ie, presenting in extremis with little or no cardiovascular or respiratory activity, and unlikely to respond to insertion of a laryngoscope). If so, the crash airway algorithm© is used (algorithm 3) .
If the patient is not a crash airway, the next step is to determine if the patient presents a difficult airway. This requires assessment of specific patient attributes to predict the likelihood of difficulty in performing any of the major procedures in airway management: direct laryngoscopy and intubation, bag-mask ventilation, surgical airway management, and ventilation using an extraglottic airway.
If the patient is felt to be neither a crash nor a difficult airway, then rapid sequence intubation is the recommended method for managing the airway. (See "Rapid sequence intubation in adults".)
The decision that the patient presents with a difficult airway is a critical determinant of the best approach to intubation. This topic review will discuss assessment and management of the difficult airway in adults. Other aspects of airway management, including pediatric airway management, are discussed separately. (See "The difficult pediatric airway" and "Emergency endotracheal intubation in children" and "Basic airway management in adults" and "Advanced emergency airway management in adults" and "Rapid sequence intubation in adults".)
- Walls RM. The emergency airway algorithms. In: Manual of Emergency Airway Management, 4th, Walls RM, Murphy MF. (Eds), Lippincott Williams and Wilkins, Philadelphia 2012. p.24.
- The airway management algorithms cited in this review are reproduced with permission from: The Difficult Airway Course™: Emergency, and Walls RM, Murphy MF. Manual of Emergency Airway Management, Lippincott Williams & Wilkins, Philadelphia 2008, and 4th ed, 2012.
- Brown CA, Bair AE, Pallin DJ, Walls RM, on behalf of the NEAR III investigators: The Changing Landscape of Adult Emergency Airway Management: Emergency Department Tracheal Intubations from 2002-2012. Ann Emerg Med 2014; in press.
- Orebaugh SL. Difficult airway management in the emergency department. J Emerg Med 2002; 22:31.
- Martin LD, Mhyre JM, Shanks AM, et al. 3,423 emergency tracheal intubations at a university hospital: airway outcomes and complications. Anesthesiology 2011; 114:42.
- Cormack RS, Lehane J. Difficult tracheal intubation in obstetrics. Anaesthesia 1984; 39:1105.
- Burkle CM, Walsh MT, Harrison BA, et al. Airway management after failure to intubate by direct laryngoscopy: outcomes in a large teaching hospital. Can J Anaesth 2005; 52:634.
- Langeron O, Masso E, Huraux C, et al. Prediction of difficult mask ventilation. Anesthesiology 2000; 92:1229.
- Kheterpal S, Han R, Tremper KK, et al. Incidence and predictors of difficult and impossible mask ventilation. Anesthesiology 2006; 105:885.
- El-Orbany M, Woehlck HJ. Difficult mask ventilation. Anesth Analg 2009; 109:1870.
- Salem MR, Ovassapian A. Difficult mask ventilation: what needs improvement? Anesth Analg 2009; 109:1720.
- Gautam P, Gaul TK, Luthra N. Prediction of difficult mask ventilation. Eur J Anaesthesiol 2005; 22:638.
- Yildiz TS, Solak M, Toker K. The incidence and risk factors of difficult mask ventilation. J Anesth 2005; 19:7.
- Kheterpal S, Martin L, Shanks AM, Tremper KK. Prediction and outcomes of impossible mask ventilation: a review of 50,000 anesthetics. Anesthesiology 2009; 110:891.
- Kheterpal S, Healy D, Aziz MF, et al. Incidence, predictors, and outcome of difficult mask ventilation combined with difficult laryngoscopy: a report from the multicenter perioperative outcomes group. Anesthesiology 2013; 119:1360.
- Rose DK, Cohen MM. The airway: problems and predictions in 18,500 patients. Can J Anaesth 1994; 41:372.
- Bair AE, Panacek EA, Wisner DH, et al. Cricothyrotomy: a 5-year experience at one institution. J Emerg Med 2003; 24:151.
- Wright MJ, Greenberg DE, Hunt JP, et al. Surgical cricothyroidotomy in trauma patients. South Med J 2003; 96:465.
- Shafik MT, Bahlman BU, Hall JE, Ali MS. A comparison of the Soft Seal disposable and the Classic re-usable laryngeal mask airway. Anaesthesia 2006; 61:178.
- Ochs M, Vilke GM, Chan TC, et al. Successful prehospital airway management by EMT-Ds using the combitube. Prehosp Emerg Care 2000; 4:333.
- Lefrançois DP, Dufour DG. Use of the esophageal tracheal combitube by basic emergency medical technicians. Resuscitation 2002; 52:77.
- Davis DP, Valentine C, Ochs M, et al. The Combitube as a salvage airway device for paramedic rapid sequence intubation. Ann Emerg Med 2003; 42:697.
- Calkins TR, Miller K, Langdorf MI. Success and complication rates with prehospital placement of an esophageal-tracheal combitube as a rescue airway. Prehosp Disaster Med 2006; 21:97.
- Bair AE, Filbin MR, Kulkarni RG, Walls RM. The failed intubation attempt in the emergency department: analysis of prevalence, rescue techniques, and personnel. J Emerg Med 2002; 23:131.
- American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Practice guidelines for management of the difficult airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology 2003; 98:1269.
- Apfelbaum JL, Hagberg CA, Caplan RA, et al. Practice guidelines for management of the difficult airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology 2013; 118:251.
- Murphy M, Walls RM. Identification of the difficult and failed airway. In: Manual of Emergency Airway Management, Walls RM, Murphy MF, Luten RC. (Eds), Lippincott Williams & Wilkins, Philadelphia 2004. p.70.
- The mnemonics for difficult airway identification cited in this review are reproduced with permission from The Difficult Airway Course™: Emergency.
- Reed MJ, Dunn MJ, McKeown DW. Can an airway assessment score predict difficulty at intubation in the emergency department? Emerg Med J 2005; 22:99.
- Tremblay MH, Williams S, Robitaille A, Drolet P. Poor visualization during direct laryngoscopy and high upper lip bite test score are predictors of difficult intubation with the GlideScope videolaryngoscope. Anesth Analg 2008; 106:1495.
- Cavus E, Kieckhaefer J, Doerges V, et al. The C-MAC videolaryngoscope: first experiences with a new device for videolaryngoscopy-guided intubation. Anesth Analg 2010; 110:473.
- Lundstrøm LH, Møller AM, Rosenstock C, et al. High body mass index is a weak predictor for difficult and failed tracheal intubation: a cohort study of 91,332 consecutive patients scheduled for direct laryngoscopy registered in the Danish Anesthesia Database. Anesthesiology 2009; 110:266.
- Juvin P, Lavaut E, Dupont H, et al. Difficult tracheal intubation is more common in obese than in lean patients. Anesth Analg 2003; 97:595.
- Connor CW, Segal S. The importance of subjective facial appearance on the ability of anesthesiologists to predict difficult intubation. Anesth Analg 2014; 118:419.
- Naguib M, Scamman FL, O'Sullivan C, et al. Predictive performance of three multivariate difficult tracheal intubation models: a double-blind, case-controlled study. Anesth Analg 2006; 102:818.
- 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.
- Samsoon GL, Young JR. Difficult tracheal intubation: a retrospective study. Anaesthesia 1987; 42:487.
- Lee A, Fan LT, Gin T, et al. A systematic review (meta-analysis) of the accuracy of the Mallampati tests to predict the difficult airway. Anesth Analg 2006; 102:1867.
- Lundstrøm LH, Vester-Andersen M, Møller AM, et al. Poor prognostic value of the modified Mallampati score: a meta-analysis involving 177 088 patients. Br J Anaesth 2011; 107:659.
- Crosby ET. Considerations for airway management for cervical spine surgery in adults. Anesthesiol Clin 2007; 25:511.
- Crosby ET. Airway management in adults after cervical spine trauma. Anesthesiology 2006; 104:1293.
- Conlon NP, Sullivan RP, Herbison PG, et al. The effect of leaving dentures in place on bag-mask ventilation at induction of general anesthesia. Anesth Analg 2007; 105:370.
- Aslani A, Ng SC, Hurley M, et al. Accuracy of identification of the cricothyroid membrane in female subjects using palpation: an observational study. Anesth Analg 2012; 114:987.
- Weingart SD, Trueger NS, Wong N, et al. Delayed sequence intubation: a prospective observational study. Ann Emerg Med 2015; 65:349.
- Benumof JL, Dagg R, Benumof R. Critical hemoglobin desaturation will occur before return to an unparalyzed state following 1 mg/kg intravenous succinylcholine. Anesthesiology 1997; 87:979.
- Incidence of difficult intubation
- Incidence of difficult bag-mask ventilation
- Incidence of difficult cricothyrotomy
- Incidence of difficult extraglottic airways
- IDENTIFICATION OF THE DIFFICULT AIRWAY
- The LEMON© approach to difficult airway assessment
- - L: Look externally
- - E: Evaluate (3-3-2 rule)
- - M: Mallampati score
- - O: Obstruction/Obesity
- - N: Neck mobility
- Difficult bag-mask ventilation
- Difficult cricothyrotomy
- Difficult extraglottic airway placement
- THE DIFFICULT AIRWAY ALGORITHM©
- Applying the algorithm
- - Is the operator forced to act?
- - Is there time?
- - Is RSI reasonable?
- - Awake technique
- - Alternatives
- Failed airway
- SUMMARY AND RECOMMENDATIONS