DIAGNOSTIC ACCURACY OF HYOMENTAL DISTANCE RATIO FOR PREDICTION OF DIFFICULT VISUALIZATION OF LARYNX

For general Anesthesia most of the time we use ETT and some time it is very difficult to pass ETT and some time it is even impossible to pass ETT which can lead to morbidity and mortality. There are different clinical methods to assess such a difficult intubation before induction of anesthesia like Mallampati classification, upper lip bite test, Lemon score, thyromental distance and hyomental distance ratio. Objectives: To find the diagnostic accuracy of the hyomental distance ratio for the prediction of difficult visualization of larynx. Material & Methods: This cross-sectional study was done at Mayo Hospital Lahore. Total 250 patients undergoing elective surgeries with general anesthesia were included. After approval from ethical committee inform consents and their basic demographic detail were taken. All anesthetics procedures and assessments were done by single consultants. Position of patient was supine with firmed head with the table. All Patients were advised to look straight by keeping head in neutral position with mouth close and no swallowing at the time of assessment. Results: Mean age of patients were 39.12±38.50 years. There were 109(43.6%) Male & 141(56.4%) female cases. 45(18%) cases were assessed as difficult visualization on Cormack Lehane and 50(20%) cases were having difficult visualization on hyomental distance ratio. The sensitivity, specificity, positive predictive value, negative predictive value and overall diagnostic accuracy of hyomental distance ratio  was 89.89%, 95.12%, 80%, 97.50% & 94% taking Cormack Lehane as gold standard and P-value was ˂ 0.05. Conclusion: The diagnostic accuracy of the hyomental distance Ratio was found high for prediction of difficult visualization of larynx by taking Cormack Lehane as gold standard.