[Comparison of the view of the glottic opening through Macintosh and AirTraq laryngoscopes in patients undergoing scheduled surgery].

BACKGROUND AND OBJECTIVE: The AirTraq laryngoscope is a new intubation device that may provide better viewing conditions than can be achieved with the traditional Macintosh device. This study compared the AirTraq and Macintosh views and assessed whether predictors of intubation difficulty are useful when the AirTraq laryngoscope is used.

MATERIAL AND METHODS: Prospective study of 215 ASA 1-3 patients over the age of 18 years who were to receive anesthesia with endotracheal intubation. Excluded were patients who required emergency surgery, who had a history of difficult intubation, or for whom ventilation was difficult during induction of anesthesia. In addition to the usual patient characteristics, we recorded thyromental distance, mouth opening, and Mallampati score. The Cormack-Lehane laryngoscopy grade was recorded for each device. A Cormack-Lehane grade of 1 or 2 was considered a good view. A grade of 3 or 4 was considered a poor view. The McNemar test was used to compare laryngoscopy grade between the 2 devices in each patient. The chi2 test was used to compare predictors of intubation difficulty.

RESULTS: The Macintosh laryngoscope achieved a Cormack-Lehane grade of 1 in 653% of the patients, of 2 in 22.4%, of 3 in 11.3%, and of 4 in 1.4%. The AirTraq scope gave a Cormack-Lehane grade of 1 in 96.2%, of 2 in 33%, of 3 in 0.5%, and of 4 in 0%. The differences were statistically significant. None of the predictors was associated a poor glottic view through the AirTraq device.

CONCLUSIONS: Poor viewing conditions occurred less frequently when the AirTraq device was used. Intubation conditions were therefore better with the AirTraq than with the Macintosh device. The traditional predictors of difficult intubation do not seem to be relevant when the AirTraq device is to be used.