Authors: Seth T. Herway, M.D. et al
Anesthesiology 7 2017, Vol.127, 201-202.
To the Editor:
The article by Aziz et al.1 significantly contributes toward understanding the response of anesthesiologists to failed intubation attempts with conventional direct laryngoscopy. We are concerned, however, that one unwise message that may be drawn from this paper is that video laryngoscopy is the sine qua non for management of an unexpected difficult direct laryngoscopy. Indeed, Aziz et al.found an 8% failure rate with video laryngoscopy (90 of 1,122), underscoring the fact that anesthesiologists must have other trusted responses to failed conventional direct laryngoscopy. Additionally, it must be recognized that video laryngoscopy is an apneic intubation technique; oxygenation and ventilation are not maintained during laryngoscopy and intubation.
Aziz et al. reported inferior success rates with both intubation using a supraglottic airway as a conduit and intubation using a flexible fiberoptic bronchoscope (78% for both vs. 92% with video laryngoscopy). However, there are two important considerations to weigh when evaluating intubations using a supraglottic airway and/or fiberoptic bronchoscopy in these situations. First, because this was a multicenter study and no data were reported regarding the practitioners’ prior training and experience with any of these techniques, it is impossible to know whether practitioners had equal competence with all three techniques. In general, most practitioners have more experience with video laryngoscopy. It is entirely possible that in experienced hands the success rates for intubation using a supraglottic airway as a conduit and intubation using a flexible fiberoptic bronchoscope would be higher. Second, and most importantly, many intubation techniques using a supraglottic airway and/or fiberoptic bronchoscopy allow for continuous ventilation during airway management and intubation, an advantage that video laryngoscopy does not offer and one that can be critical when a difficult intubation occurs in the setting of difficult or impossible mask ventilation. Previously described techniques for intubation using a supraglottic airway as a conduit and intubation using flexible fiberoptic bronchoscopy while maintaining continuous ventilationinvolve placing a supraglottic airway or an intubating oral airway with a mask and connecting the supraglottic airway or the mask to the ventilator using a bronchoscopy elbow.2–4 An Aintree catheter can then be loaded onto a fiberoptic bronchoscope and advanced through the bronchoscopy elbow, through the supraglottic airway or mask and intubating oral airway combination and into the trachea, all while continuously oxygenating and ventilating the patient. An endotracheal tube is then threaded over the intratracheal Aintree catheter, and the Aintree catheter is removed.2 Alternatively, an endotracheal tube can be placed within an in situ intubating supraglottic airway and the ventilator connected to a bronchoscopy elbow placed on the endotracheal tube. Again, continuous oxygenation and ventilation are maintained as a fiberoptic bronchoscope is passed through the bronchoscopy elbow, through the endotracheal tube placed within the supraglottic airway, and into the trachea. The endotracheal tube is then advanced over the fiberoptic bronchoscope and into the trachea.3,4
Effective fiberoptic-guided intubation is a skill that, although infrequently necessary, is critical in its ability to continuously oxygenate and ventilate the patient when a difficult laryngoscopy occurs in the setting of difficult or impossible mask ventilation. This critical advantage over video laryngoscopy should not be underestimated, and indeed, the American Society of Anesthesiologists Difficult Airway Algorithm encourages practitioners to “actively pursue opportunities to deliver supplemental oxygen throughout the process of difficult airway management.”5
It is imperative that the anesthesiology community continue to teach residents techniques for airway management beyond direct and video laryngoscopy with a focus on those techniques that allow for continuous oxygenation and ventilation during airway management. Equally as important, once these skills are attained, anesthesiologists must make efforts to maintain these skills through their practical application. We hope that, rather than highlighting the efficacy of video laryngoscopy over other techniques, the article by Aziz et al. will serve to underscore the importance of the competent practitioner having an arsenal of techniques, with which they are well versed, to secure the difficult airway.
Seth T. Herway, M.D. University of California San Diego, San Diego, California (S.T.H.).
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Hollingsworth, JG, Herway, ST, Benumof, JL, Finneran, J Exchanging a King Laryngeal TubeTM for an endotracheal tube using a fiberoptic bronchoscope-Aintree catheter combination in a known difficult airway. Can J Anaesth 2017; 64:337–8
Olesnicky, BL, Rehak, A, Bestic, WB, Brock, JT, Watterson, L A cadaver study comparing three fibreoptic-assisted techniques for converting a supraglottic airway to a cuffed tracheal tube. Anaesthesia 2017; 72:223–9
Lee, AY, Benumof, JL Fiberoptic intubation through adapter removable supraglottic airways: Comparison of the Air-Q LMA, LMA Classic Excel, and LMA Unique. Open J Anesth 2014; 4:111–18.
Apfelbaum, JL, Hagberg, CA, Caplan, RA, Blitt, CD, Connis, RT, Nickinovich, DG, Hagberg, CA, Caplan, RA, Benumof, JL, Berry, FA, Blitt, CD, Bode, RH, Cheney, FW, Connis, RT, Guidry, OF, Nickinovich, DG, Ovassapian, A 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 2013; 118:251–70