A clinical sign to predict difficult tracheal intubation: a prospective study.

It has been suggested that the size of the base of the tongue is an important factor determining the degree of difficulty of direct laryngoscopy. A relatively simple grading system which involves preoperative ability to visualize the faucial pillars, soft palate and base of uvula was designed as a means of predicting the degree of difficulty in laryngeal exposure. The system was evaluated in 210 patients. The degree of difficulty in visualizing these three structures was an accurate predictor of difficulty with direct laryngoscopy (p less than 0.001).