Predicting Difficult Videolaryngoscopic Intubation in Patients with Obesity Using Ultrasound: An Observational, Prospective Study

BACKGROUNDː This study aimed to assess the effectiveness and validity of ultrasonographic measurements in predicting difficult videolaryngoscopic intubation in patients with obesity.METHODSː This observational prospective study included 140 patients with obesity who were scheduled for elective laparoscopic bariatric surgery under general anesthesia. Following tracheal intubation during anesthesia induction, patients were classified into either the non-difficult or difficult intubation group based on the Videolaryngoscopic Intubation and Difficult Airway Classification scale. Clinical and ultrasonographic airway parameters were recorded during the pre-anesthetic evaluation. Receiver operating characteristic curves were generated to assess the diagnostic performance of the airway measurements.RESULTSː Of the 140 enrolled patients, 128 were analysed, with 101 classified as non-difficult and 27 as difficult intubations. Skin-to-tongue thickness and the distance from the skin to the epiglottis (DSE) were the two most reliable predictors of difficult intubation, with area under the curve (AUC) values of 0.776 [95% confidence interval (CI): 0.672–0.879] and 0.774 (95% CI: 0.678–0.869), respectively. The LEMON (Look-Evaluate-Mallampati-Obstruction-Neck mobility) score, skin-to-tongue thickness, and DSE were identified as independent risk factors for predicting difficult intubation. When these three parameters were combined, predictive performance improved, with an AUC of 0.845 (95% CI: 0.760–0.929).CONCLUSIONSː The combination of the LEMON score, skin-to-tongue thickness, and DSE demonstrated superior predictive accuracy compared to any single parameter for identifying difficult videolaryngoscopic intubation in obese patients.