Comparison of Neck Extension versus Ultrasound Guided Distance Measured From Skin to Epiglottis (DSE) As Sole Predictors of Difficult Intubation

Abstract

Objective: The objective of this study is to compare the conventional measurement of neck extension versus ultrasound guided distance measured from skin to epiglottis (DSE) as sole predictors in determining difficult airway and laryngoscopy. Study Design & Setting: Prospective observational study. Anesthesia department of Combined Military Hospital, Rwp from Jan-Jun 2023. Methodology: All the patients included in the study were divided into two groups, Group N (n=75) undergoing neck extension as sole predictor and Group E (n=75) using DSE by USG as a sole predictor for difficulty airway. Primary variables measured were the sensitivity, specificity, positive and negative predicted values for neck extension and ultrasound guided DSE when compared with the outcome of the gold standard Cormack Lehane classification at intubation. Results: Comparison of sensitivity and specificity of both parameters in diagnosing difficult airway showed a sensitivity of 76.9% in Group N (neck extension) versus 88.4% in Group E (DSE). Specificity showed 69.4% in Group N versus 87.5% in Group E. Neck extension had a positive predictive value of 73.2% whereas DSE was superior with a positive predictive value of 90.5%. The negative predictive value was also considerably less with neck extension as the sole perimeter with 73.5% versus 84.8% when DSE was used. Conclusion: We conclude that the ultrasound guided distance measured from skin to epiglottis is superior to conventional neck extension when used as sole agents to diagnose difficult airway in suspected patients