Abstract
INTRODUCTION: Anticipation of a difficult airway is essential for safe anesthesia. Unanticipated difficult intubations remain a major cause of morbidity and mortality in the perioperative period. Several bedside airway assessment tests exist, but their accuracy varies. AIM: To compare the predictive value of the Modified Mallampati Test (MMT), Upper Lip Bite Test (ULBT), and Thyromental Distance (TMD) against the Cormack-Lehane (CL) grading for predicting difficult intubation. MATERIALS AND METHODS: A prospective observational study was conducted on 150 ASA I-II patients (18-60 years) scheduled for elective surgery under general anesthesia. Preoperative airway assessment included MMT, ULBT, and TMD performed by a single anesthesiologist. Direct laryngoscopy was performed under standardized anesthesia, and CL grades were recorded. Grades III-IV were considered difficult intubation. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of each bedside test were calculated using CL grading as the gold standard. RESULTS: Difficult intubation was encountered in 20 patients (13.33%), with 18 graded CL III and 2 graded CL IV. Sensitivity and specificity were: MMT - 45% and 96.15%; TMD - 65% and 94.61%; ULBT - 80% and 96.92%. ULBT showed the highest predictive accuracy. CONCLUSION: ULBT demonstrated superior sensitivity and specificity among the tests evaluated, but no single bedside test was sufficiently accurate to predict all difficult intubations. A combination of tests is recommended for preoperative airway assessment.