Comparison between El-Ganzouri risk index and sonologically measured skin-to-epiglottis distance for predicting difficult laryngoscopy: A prospective observational study.

Background and Aims: Anticipating and planning for difficult airway management decreases perioperative airway catastrophes. The primary objective of the study was to determine the predictor of a difficult laryngoscopy by comparing clinically measured El-Ganzouri risk index (EGRI) and sonologically measured skin-to-epiglottis distance (SED). Methods: The study was conducted on 129 American Society of Anesthesiologists (ASA) class I or II patients aged 25-70 years requiring tracheal intubation. Preoperative airway assessment was done using EGRI and SED and correlated with Cormack-Lehane (CL) laryngoscopic view. The sensitivity and specificity of SED were compared with EGRI. The receiver operating characteristics (ROC) curve was plotted, and the area under the curve (AUC) was calculated for SED and EGRI. Results: EGRI score has a sensitivity of 88.9%, specificity of 6.7%, positive predictive value (PPV) of 33.3%, and negative predictive value (NPV) of 99%. We found a sensitivity of 96%, specificity of 100%, PPV of 100%, and NPV of 99% with a SED value of 18 mm. The statistical association between ultrasonologically measured SED at the level of thyrohyoid membrane for predicting difficult laryngoscopy has more sensitivity and specificity than EGRI. Conclusion: Sonologically measured SED is a better parameter in terms of sensitivity and specificity to predict the difficulty in laryngoscopy than EGRI, and the combination of EGRI with SED increases the accuracy of EGRI alone. In this study, a new cut-off value of 15 mm was obtained from the coordinates of the ROC curve for SED measurement, even though 18 mm was used in this study.