Comparative Study of Clinical and Ultrasound Parameters for Defining a Difficult Airway in Patients with Obesity

Patients with obesity have anatomical changes due to increased adipose tissue that negatively affect airway accessibility, making it difficult to establish an advanced airway through orotracheal intubation. This article aims to evaluate the correlation of clinical and sonographic parameters as predictors of difficult airway management (DAM) in patients with obesity and to establish the predictive value of the skin-epiglottis distance as an indicator of a probable DAM.

This is an observational, prospective study of 100 patients with obesity who underwent bariatric surgery over a 12-month period. The patients were categorized into the easy airway and the difficult airway groups, according to the Cormack-Lehane classification in the laryngoscopy evaluation, and the clinical and sonographic variables collected were statistically evaluated to obtain the relation with the presence of DAM, according to the Cormack-Lehane classification.

The mouth opening (p = 0.010) and the skin-epiglottis distance (p = 0.019) were statistically significant when comparing the easy airway and the difficult airway groups of the Cormack-Lehane classification. The predictive value of the skin-epiglottis distance for difficult airway assessment was 29.3 mm. The neck circumference (p = 0.225), the Mallampati index (p = 0.260), and the other clinical variables showed no statistical relevance when compared in isolation with the Cormack-Lehane groups.

The ultrasound method as a predictor of difficult intubation is promising in anesthetic practice when used according to standardized measurements evaluation and cutoff values.