Laryngeal mask airway positioning is related to Mallampati grading in adults

The Mallampati classification is a commonly used means of preoperatively predicting a difficult endotracheal intubation. As the laryngeal portion of the laryngeal mask airway (LMA) must sit over the larynx, we wondered whether the Mallampati classification also predicts difficulty in achieving adequate seating of the LMA. LMA positioning was assessed prospectively in 100 adult patients by fiberoptic bronchoscopy to determine whether there was a relationship between the ease of seating of the LMA and the Mallampati classification. In 72 patients, optimal seating of the LMA was achieved on the first attempt at insertion, and all these patients were classified as Mallampati class 1 or 2. In all 28 cases of difficulty with LMA insertion, the patients were Mallampati class 2 or 3. In two cases the LMA was abandoned, and in these cases both patients were Mallampati class 3, (P = 0.0001 by chi 2 analysis). We conclude that the Mallampati classification indicates difficulty not only in tracheal intubation but also in achieving an adequate airway with the LMA.