Predicting difficult intubation--a comparison between Mallampati classification and Wilson risk-sum.

OBJECTIVE

To compare the Mallampati classification and Wilson risk-sum and adopt a predictive rule in our setup that has better results.

DESIGN

An analytical study.

PLACE AND DURATION OF STUDY

The main Operation Theatre of Combined Military Hospital, Rawalpindi from 1st September to 31st December 2000.

PATIENTS AND METHODS

Three hundred and thirty-eight patients were evaluated pre-operatively for difficult intubation using both the tests. The sensitivities, specificities and positive predictive values (PPV) were determined in grading the laryngeal view in each case during direct laryngoscopy.

RESULTS

Both tests identified only 3 out of 7 difficult intubations, giving a similar sensitivity of 0.42. Twice as many patients were predicted to be difficult by Mallampati classification than by Wilson risk-sum (specificity 84% and 93%). The Wilson risk-sum had better positive predictive value (11%) as compared to 5% of Mallampati classification.

CONCLUSION

The Wilson risk-sum had preferred for assessment of the airway because of its better specificity and positive predictive value while noting that both tests have poor sensitivities when used alone.