PREOPERATIVE ASSESSMENT FOR DIFFICULT INTUBATION IN GENERAL AND ENT SURGERY - PREDICTIVE VALUE OF A CLINICAL MULTIVARIATE RISK INDEX

Several clinical multifactorial indexes have been described for predic ting difficult laryngoscopy or intubation, or both, mostly in general surgery, and less frequently in ENT surgery. The objective of this stu dy was to develop and validate a single clinical index for prediction of difficulty in tracheal intubation in both ENT and general surgery. We studied a population of 1200 consecutive ENT and general surgical p atients. Clinical criteria were tested using univariate and multivaria te analysis. Difficult intubation was defined as requiring unusual tec hniques. Logistic regression identified seven criteria as independent predictors of difficult tracheal intubation: previous history of diffi cult intubation; pathologies associated with difficult intubation; cli nical symptoms of pathological airway; inter-incisor gap and mandible luxation; thyromental distance; head and neck movement; and Mallampati 's modified test. Point values were assigned to each of these factors in proportion to regression coefficients representing the relative wei ght of each predictive intubation difficulty factor, the sum comprisin g the score. The best predictive threshold was chosen using a receiver operating characteristic curve. We then prospectively studied and val idated the score in a population of 1090 consecutive ENT and general s urgery patients. The sensitivity and specificity of the predictions we re 94% and 96% in general surgery, 90% and 93% in non-cancer ENT surge ry, and 92% and 66% in ENT cancer surgery, respectively.