Clinical comparison of five different predictor tests for difficult intubation

Abstract

Introduction: The objective of this study was to compare various bedside tests including Modified Mallampati Test (MMT), thyro mental distance (TMD), sternomental distance (SMD), Inter Incisor Gap (IIG) and combination of the modified Mallampati test and thyromental distance for predicting difficult intubation.

Methods: A cross sectional study was conducted on 301 nonobese patients (18-72 years of age) without obvious airway pathology. All patients belonged to the American Society of Anesthesiology (ASA) class 1 or 2 and were scheduled for elective surgery that required general anesthesia. Airway assessment was performed and the appropriate scores were assigned for each predictor test. Difficult intubation was defined as Grade III or IV based on the Cormack- Lehane classification on laryngoscopic view.

Results: All tests except TMD (71.43%) showed very poor sensitivity and very high specificity. Area under the curve was good (0.8 to 0.9) for all the tests. Posttest probability showed that all of the bedside tests have limited clinical value.

Conclusion: All four predictor tests for difficult intubation have only poor to moderate discriminative power when used alone. Combination of Modified Mallampati and Thyromental distance test adds some incremental diagnostic value in comparison to the value of each test alone.

Citation: Badhe VK, Deogaonkar SG, Tambe  MV, Singla A, Shidhaye RV. Clinical comparison of five different predictor tests for difficult intubation. Anaesth Pain & Intensive Care 2014;18(1):31-37