Prediction of difficult laryngoscopy: does obesity play a role?

OBJECTIVES

This study was intended to 1) identify preoperative predictors of difficult laryngoscopy and 2) determine the role of obesity in difficulty of obtaining adequate laryngeal exposure.

METHODS

A prospective study was undertaken of 63 patients who were undergoing elective direct laryngoscopy. Thirty-six patients met the obesity criteria (body mass index of at least 30 kg/m2). Measurements of height, weight, and neck circumference and Mallampati and Cormack-Lehane scores were obtained. The ease of laryngeal exposure was recorded by the attending surgeon on a visual analog scale (VAS; 1 to 10). Difficult laryngeal exposure (DLE) was defined as a VAS score of at least 3. The candidate morphological predictors were investigated.

RESULTS

Obesity and Mallampati score were found to be predictors of DLE (p < .001). The VAS score was positively correlated with body mass index (p = .007), weight (p = .05), Mallampati score (p < .001), and Cormack-Lehane score (p < .001). Among obese patients, the VAS score was correlated with the Cormack-Lehane score (p = .01), whereas in nonobese patients the VAS score showed a significant association with both the Mallampati (p = .02) and Cormack-Lehane (p = .01) scores.

CONCLUSIONS

Obese patients and those with a Mallampati score of at least 2 posed a significantly higher risk of DLE. Preoperative identification of a potentially difficult airway may aid surgical planning and allow more effective communication with a collaborating anesthesiologist.