Comparison of two methods for predicting difficult intubation.

Two methods of predicting difficult laryngoscopy were compared prospectively. Mallampati class and Wilson risk-sum were determined before operation and laryngeal view graded in 675 patients. Both tests identified five of 12 difficult laryngoscopies; twice as many patients were predicted to be difficult by Mallampati classification than by Wilson risk-sum. Inter-observer variation was minimal using Wilson risk-sum, but considerable for Mallampati classification. We prefer the Wilson risk-sum for assessment of the airway, while noting that both tests have poor sensitivities.