A Prospective Comparative Study of Upper Lip Bite Test, Thyromental Distance, Sternomental Distance and Modified Mallampati with Cormack Lehane Grading for Predicting Difficulty During Endotracheal Intubation

Predicting Difficult airway During Endotracheal Intubation

Abstract

Background: Numerous tests for predicting difficult laryngoscopy and intubation have been incorporated in our routine anaesthesia practice. Failure to predict a Difficult laryngoscopy and intubation can cause increased risk of complications to patient ranging from sore throat to airway trauma, it may also lead to serious complications like hypoxic brain damage and death. Our study aimed at assessing the efficacy of preoperative airway assessment for predicting a difficulty airway with regard to Cormack Lehane grading on direct laryngoscopy. Objective: To predict difficulty in larngoscopy and intubation using upperlip bite test, thyromental distance, sternomental distance and modified Mallampati with regard to Cormack lehane grading. Subjects and Methods: Hospital based prospective study. Study area: Department of Anaesthesia, at YASHODA HOSPITAL, Malakpet branch, Hyderabad, Telangana. Study Period: April 2022 March 2023.  Study design:  100 patients aged between 18-70 years were included in the study. After obtaining informed consent, information was collected from patients who fulfilled our selection criteria. Relevant history and systemic conditions of the patients were noted. Malampatti Grading (MPG), Sternomental Distance (SMD), Thyromental Distance(TMD) And Upper Lip Bite Test(ULBT) were performed in every patient and their efficacy in predicting a difficult airway was assessed by comparing the Cormack lehane grading on direct laryngoscopy view. Results: According to our study ULBT and MPG were better in predicting a difficult airway on laryngoscopy with had sensitivity 88.9% & 83.3% and specificity of 97.6% & 90.2% respectively. TMD and SMD had poor PPV of 47.8% and 48.1% respectrively. Conclusion: Our study found that ULBT and MPG were were good predictors for both easy and difficult airways. However, SMD and TMD could predict an easy intubation accurately but failed in predicting a difficult laryngoscopy.