Co-Relation Between USG- Guided Methods and Conventional Methods for the Assessment of Airway and Cormack Lehane Grading in Adult Patients - A Randomized, Double Blinded Prospective Observational Study

Abstract

Background: A comprehensive examination of the airway is essential for secure anesthetic administration. Conventional clinical evaluations, like the Mallampati classification and thyromental distance, are commonly employed although frequently lack reliability in predicting challenging airway situations. The introduction of point-of-care ultrasonography (POCUS) has established non-invasive imaging as a valuable supplement in preoperative airway assessment. This study examines the efficacy of ultrasound-guided measurements relative to traditional methods in forecasting Cormack-Lehane (CL) grades during laryngoscopy.

Objective: To evaluate the predicted accuracy of ultrasound-guided assessment compared to conventional methods in identifying difficult laryngoscopy, as indicated by CL grading, and to ascertain whether their combination improves overall predictive performance.

Method: A randomized, double-blind, prospective observational study was performed at the Indira Gandhi Institute of Medical Sciences in Patna over the course of one year. One hundred twenty adult patients scheduled for elective procedures under general anesthesia were enrolled. Airway evaluations were conducted utilizing conventional methods (Mallampati classification, thyromental distance, etc.) and ultrasound-assisted metrics (skin-to-epiglottis distance [SED], hyomental distance ratio [HMDR], etc.). The anesthesiologist conducting the intubation was unaware of the evaluations. The link with CL grades was examined by Pearson correlation, logistic regression, and ROC curves.

Result: Ultrasound-guided metrics exhibited enhanced prediction precision relative to traditional techniques. SED ?2.54 cm and HMDR ?1.2 were substantially correlated with challenging laryngoscopy (CL Grade III–IV), with sensitivities of 78.5% and 83.3%, respectively. Conversely, conventional procedures like Mallampati class III–IV and thyromental distance <6.5 cm exhibited diminished sensitivities (47.6% and 59.4%). The integration of two modalities resulted in the highest prediction accuracy, achieving an AUC of 0.93.

Conclusion: Ultrasound-guided airway assessment is a dependable, objective, and reproducible method that improves the prediction of challenging intubation. When combined with traditional clinical methods, it markedly enhances the sensitivity and specificity of airway assessment. Integrating POCUS into conventional preoperative screening techniques may improve patient safety and diminish airway-related problems.

Keywords: Airway examination, ultrasonography, Cormack-Lehane classification, endotracheal intubation, point-of-care ultrasound, preoperative assessment