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Correspondence  |   July 2007
More Trouble with Airway Definitions
Author Notes
  • (Accepted for publication February 22, 2007.)
    (Accepted for publication February 22, 2007.)×
Article Information
Correspondence
Correspondence   |   July 2007
More Trouble with Airway Definitions
Anesthesiology 7 2007, Vol.107, 170. doi:10.1097/01.anes.0000268503.05315.e5
Anesthesiology 7 2007, Vol.107, 170. doi:10.1097/01.anes.0000268503.05315.e5
To the Editor:—
In Dr. Yentis' interesting editorial,1  he points out the limited value of predictive airway tests. I would like to raise issues with two aspects of these tests relating to the difficult airway. The first concerns the predictors of “difficult laryngoscopy.” There are a variety of tests intended to identify the patient in whom laryngoscopy may be difficult. Although it is generally acknowledged that individually, these tests have low specificity, it is important to emphasize that they were all designed specifically for direct laryngoscopy, often for a specific laryngoscope blade, and may have no relevance when using other methods of introducing an endotracheal tube, such as a lighted stylet, a rigid or flexible fiberoptic endoscope, or an anatomically shaped videolaryngoscope. Therefore, when we speak of a patient with characteristics associated with difficult intubation, this does not necessarily mean that the patient is difficult to intubate using an alternative device.
Yentis also points out that the quality of the laryngeal view is frequently used as a surrogate for difficult laryngoscopy. If a laryngoscope is a tool used to visualize the larynx, and not simply a retractor, when it fails to provide a view of larynx (Cormack-Lehane2  views ≥ 3), should this not more properly be referred to as “failed laryngoscopy” irrespective of the success of tracheal intubation? If such a definition is accepted, failed laryngoscopies are more common. This may encourage us to develop devices and techniques that result in a higher rate of visualized intubations. We know that multiple attempts at direct laryngoscopy3  and intubation4  are associated with greater morbidity and mortality. It remains to be determined whether visualized intubation is associated with less morbidity than blind endotracheal tube passage.
Richard M. Cooper, B.Sc., M.Sc., M.D., F.R.C.P.C. University of Toronto, Toronto General Hospital, Toronto, Canada. richard.cooper@uhn.on.ca
References
Yentis, SM Predicting trouble in airway management.. Anesthesiology. (2006). 105 871–2 [Article] [PubMed]
Cormack, RS, Lehane, J Difficult tracheal intubation in obstetrics.. Anaesthesia. (1984). 39 1105– [Article] [PubMed]
Mort, TC Emergency tracheal intubation: Complications associated with repeated laryngoscopic attempts.. Anesth Analg. (2004). 99 607–13 [Article] [PubMed]
Rose, DK, Cohen, MM The airway: Problems and predictions in 18,500 patients.. Can J Anaesth. (1994). 41 372–83 [Article] [PubMed]