The New Haven Algorithm for the Evaluation of the “Unknown” Airway

Abstract

Evaluation of the airway is an essential skill for the anesthesiologist or other clinician who is placed in a position to manage the patient airway. This evaluation is complicated by both the myriad clinical situations which contribute to difficult mask ventilation and intubation, and the insensitivity of the reported airway examation tools at our routine disposal (El-Ganzouri et al. 1996; Oates et al 1991; Sawa 1994; Yamamoto et al. 1997). Likewise, there is a significant degree of interobserver variability in the grading of these indexes (Karkouti et al. 1996). Nowhere does the clinician have more difficulty in evaluating the airway than in the patient with airway disease, or a history of airway disease. Patients who present with symptoms (e.g., change of voice, stridor, snoring), mass or tumor, or a history of airway surgery and/or radiation may be considered an “unknown” unless they are properly evaluated. The conservative anesthesiologist who is faced with a patient that has presented with, for example, laryngeal polyps or a supralaryngeal tumor, should decide whether management with awake intubation (if patient age and mental status permit) will ensure complete patient safety (American Society of Anesthesiology 1993). All experienced operators are aware that this is unnecessary in most cases. Unfortunately, this is not a certainty until the airway has been visualized. In a minority of cases, this juncture will be too late if general anesthesia and apnea have been induced. In the opinion of this author, even if this represents only a minority of patients, it is still far too many.