Use of ultrasonography and traditional methods in predicting difficult airway in obese and non-obese patients

The aim of this study is to evaluate the comparative effectiveness of ultrasonographic measurements with classical clinical methods in predicting difficult airway in obese and non-obese individuals. The research was conducted at the Department of Anesthesiology and Reanimation, Pamukkale University Faculty of Medicine. 202 adult patients who will undergo elective surgery under general anesthesia in ASA I–IV class were included in the study. Patients were divided into two groups according to body mass index (BMI): obese group (BMI ≥30 kg/m2) and non-obese group (BMI <30 kg/m2). Classical airway assessment methods (Mallampati score, Upper lipe bite test, thyromental distance, STOP-Bang score) and ultrasonographic measurements (epiglottis-Decapular distance, hyoid bone-skin distance, hyomental distance, tongue base thickness, tongue volume) were taken in all patients during the preoperative period. The intubation difficulty score and Cormack-Lehane score were recorded during the intraoperative period. According to the results, epiglottis-skin distance (p<0.001), hyoid bone-skin distance (p<0.001), hyomental distance (p=0.001), tongue base thickness (p<0.001) and tongue volume (p<0.001) were found to be significantly higher in the obese group. In addition, STOP-Bang score (p=0.003), Mallampati score (p=0.002), Cormack-Lehane score (p=0.002), mask ventilation score (p=0.003) and intubation difficulty score (p=0.002) were found to be statistically significantly higher in obese individuals. Epiglottis-skin distance was measured as 26.1 mm (23.3–35.6), tongue volume was measured as 108.3 mm3 (96.1–119.2), hyomental distance was measured as 45.2 mm (41.5–49.2) in difficult laryngoscopy group and significant difference was obtained in all parameters. In addition, neck circumference, tongue volume and epiglottic distance are significantly higher in individuals with intubation difficulty score ≥5 (p<0.001). As a result, obesity leads to significant changes in all ultrasonographic and clinical parameters associated with difficult airway and complicates intubation management. Ultrasonography offers an effective and complementary contribution to the classical methods of airway assessment in these individuals.