Evaluation of Ultrasound Guided Measurement of Tongue Thickness in Predicting Difficult Tracheal Intubation in Patients Undergoing Elective Surgery: A Cross Sectional Study

Abstract

Background: Preoperative airway assessment is necessary to identify airway difficulties to the earliest, ensure adequate preparation to airway management before induction and to avoid airway related complications. Various Imaging techniques have been studied for prediction of the difficult airway. the ultrasound is a quick and simple technique. Aim of the study was to evaluate ultrasound guided measurement of tongue thickness in predicting difficult tracheal intubation in patients undergoing elective surgery.
 Methods: Sixty-one patients American Society of Anesthesiologist class I and II,18-65 years of age, either sex, were included. Tongue thickness was measured by ultrasound as the distance from the surface of tongue to the submental skin. Modified mallampatti score was also recorded.
 Results: Receiver operating characteristic (ROC) curve of tongue thickness showed an AUC of 0.879 for a cut off value of >6 cm. This shows it has an excellent predictive value. Tongue thickness (>6cm) was found to have 90.16% combined diagnostic accuracy with 75% sensitivity and 94.74% specificity for prediction of difficult intubation. No correlation between tongue thickness and modified mallampatti score. (Correlation coefficient was 0.013, p value 0.920).
 Conclusion: We conclude that ultrasound guided measurement of tongue thickness> 6 cm can reliably predict difficult tracheal intubation in patients undergoing elective surgery.