Comparison of Upper Lip Bite Test with Modified Mallampati Score in Predicting Difficult Intubation

Abstract

Background and Aims: Identifying a patient with a difficult airway is important in planning anaesthetic management so that endotracheal intubation can be achieved safely. This study aims to compare modified Mallampati score with Upper Lip Bite Test to predict difficult intubation using intubation difficulty scale. Materials and methods: A prospective study was carried on 104 patients, both sexes aged between 18 to 60 years scheduled for elective surgeries under general anaesthesia fulfilling inclusion and exclusion criteria. Patient airway was evaluated by MMT and ULBT preoperatively. Predictors of difficult endotracheal intubation were assigned to MMT class III and IV, ULBT class III. After premedication and induction laryngoscopy was performed. After successful intubation Intubation difficulty score was noted down based on the sum of seven assessing parameters. A score >5 was considered difficult intubation. Results: The incidence of difficult intubation in the study was 10.6% (i.e. 11 out of 104 patients). In this study ULBT had a higher sensitivity (90.9% v/s 18.20%), specificity (95.7% v/s 75.3%) PPV (71.4% v/s 8%) and NPV (98.9% v/s 88.6%) than that of MMT Conclusion: Upper lip bite test is better at predicting difficult intubation with higher accuracy when compared to Modified Mallampati test. Both the tests are good predictors of easy intubation. Keywords: Upper Lip Bite Test (ULBT), Modified Mallampati test (MMT), Intubation Difficulty scale (IDS), airway assessment. Difficult intubation prediction, Difficult airway