A COMPARATIVE STUDY OF MODIFIED MALLAMPATI CLASSIFICATION WITH NECK CIRCUMFERENCE ALONG WITH UPPER LIP BITE TEST IN MORBIDLY OBESE PATIENTS

Abstract

INTRODUCTION: Anaesthesia in morbidly obese patients can present many challenges. The overriding concern of most anaesthesiologists is airway management, as obese patients have been thought to be at greater risk of difcult airway and/or difcult intubation, when compared with the general population. The term 'difcult airway' has been dened by the American Society of Anaesthesiologists (ASA) taskforce as the clinical situation in which a conventionally trained anaesthesiologist experiences problems with mask ventilation or tracheal intubation or both. AIMS AND OBJECTIVES- To assess the positive predictive value,sensitivity and specicity of MMPC, NC along with ULBT and compare it with Cormack Lehane grading intraoperatively. MATERIALS AND METHOD- Preoperative airway assessment of 200 patients posted for surgery under general anaesthesia was carried out to evaluate the usefulness of multiple screening tests in predicting the ease or difculty of laryngoscopy in obese patients undergoing laparoscopic bariatric surgery. Modied Mallampati test grade III or IV, Upper Lip Bite test grade III, Neck Circumference >40cm were considered as predictors of difcult laryngoscopy. Laryngoscopy was considered difcult if the view on laryngoscopy was Cormack and Lehane grade III or IV. The results were evaluated on the basis of sensitivity, specicity, positive and negative predictive value and accuracy of these tests. RESULT- Group A (ULBT+MMPC) identied 65% of the patients with difcult intubation (sensitivity of 92.86 % & specicity of 33.3 %), whereas Group B (ULBT+NC) identied 75% of the patients with difcult airway (sensitivity 93.75% & specicity of 25%). Pearson Correlation analysis was applied to know the correlation between the various tests and the Cormack Lehane Classication, both the groups had p value of 0.001 , which was highly signicant. CONCLUSION-When multiple predictors are taken into consideration there was a considerable reduction in false negatives with signicant improvement in accuracy of test and hence prediction of difcult laryngoscopy was made easy. Application of multiple predictors in combination can reduce the frequency of unanticipated difculty and unnecessary interventions related to over prediction of airway difculty.