The usefulness of the modified laryngoscopic blade for training novice laryngoscopists.

STUDY

OBJECTIVE

The objective of this study was to evaluate the effectiveness of a modified Macintosh blade for reducing the chances of directly contacting the teeth and providing a satisfactory laryngoscopic view during laryngoscopies by novice laryngoscopists.

DESIGN

This is a prospective clinical comparison study.

SETTING

The study took place at an operating room of a university hospital.

PATIENTS: Seventy-two patients with American Society of Anesthesiologists physical statuses I and II, aged 16 to 64 years, who were scheduled for elective surgery requiring general anesthesia with endotracheal tube placement participated in this study.

INTERVENTIONS: Laryngoscopy was performed twice on each patient, once with a regular Macintosh no. 3 blade and once with a blade in which the flange was partially removed.

MEASUREMENTS: As an indirect parameter for anticipating potential dental injury during laryngoscopy, the perpendicular distance from the tip of the maxillary central incisor to the flange of each blade (the blade-tooth distance) was measured when a novice laryngoscopist lifted up the laryngoscope and visualized the glottis. We compared the blade-tooth distances, the chances of directly contacting the tooth, laryngoscopic views, and the subjective feeling of difficulty in handling the laryngoscope between the 2 blades.

MAIN

RESULTS

Blade-tooth distance varied significantly between the 2 blades: the median/interquartile range was 1.2/2.3 mm vs 3.0/4.3 mm for the regular Macintosh no. 3 and the modified blade, respectively (P<.01). The modified blade was associated with decreased chances of directly contacting the teeth (P<.05). In addition, the modified blade provided a better laryngoscopic view than did the regular blade (P<.01). Most novice laryngoscopists felt that laryngoscopy with the modified blade was significantly easier than that with the regular Macintosh blade (P<.01).

CONCLUSIONS

The modified Macintosh blade used in this study proved to be a useful device for training novice laryngoscopists with respect to procedure effectiveness and patient safety.