Airway events in obese vs. non-obese elective surgical patients: a cross-sectional observational study

Obesity is an increasingly prevalent comorbidity within the UK population. The aim of this study was to determine the proportion of obese patients in an elective surgical population. The second aim was to determine the choice of airway equipment and incidence of airway events in obese vs. non-obese patients. We conducted a cross-sectional observational study over two 24-h periods in March 2018 across 39 hospitals in the greater London area. Data were collected regarding 1874 patients. The incidence of obesity was 32% in the study population compared with 26% in the general UK population (p < 0.0001). Minor airway events were defined as: desaturation to S_p O₂ < 90%; failed mask ventilation; supraglottic airway device problem; aspiration; airway trauma and difficult intubation; or recognised oesophageal intubation. Major airway events were defined as: unrecognised oesophageal intubation; a 'cannot intubate cannot oxygenate' emergency; the need for unplanned front-of-neck airway; cardiac arrest; or unplanned intensive care unit admission due to an airway event. In total, 89 minor and two major airway events were recorded. Obese patients were more likely to experience a minor airway event (RR 2.39, 95%CI 1.60-3.57), the most common being desaturation (S_p O₂ < 90%). The use of a supraglottic airway device in obese vs. non-obese patients was associated with increased airway events (RR 3.46 [1.88-6.40]). Tracheal intubation vs. supraglottic airway device use increased with obesity class but was not associated with a decrease in airway events (RR 0.90 [0.53-1.55]). Our data suggest that obesity is more common in the elective surgical vs. general population and minor airway events are more common in obese vs. non-obese elective patients.