Associations of obesity with tracheal intubation success on first attempt and adverse events in the emergency department: An analysis of the multicenter prospective observational study in Japan

Obesity is deemed to increase the risk of difficult tracheal intubation. However, there is a dearth of research that examines the relationship of obesity with intubation success and adverse events in the emergency department (ED). We analyzed the data from a prospective, observational, multicenter study—the Japanese Emergency Airway Network (JEAN) 2 study from 2012 through 2016. We included all adults (aged 18 years) who underwent tracheal intubation in the ED. Patients were categorized into three groups according to their body mass index (BMI): lean (<25.0 kg/m), overweight (25.0–29.9 kg/m), and obesity (30.0 kg/m). Outcomes of interest were intubation success on the first attempt and intubation-related adverse events. Of 6,889 patients who are eligible for the analysis, 5,370 patients (77%) were lean, 1,177 (17%) were overweight, and 342 (4%) were obese. Compared to the lean patients, the intubation success rates were significantly lower in the overweight and obese patients (70.9% in lean, 66.4% in overweight, and 59.3% in obese patients; P<0.001). In the multivariable analysis, compared to the lean patients, overweight (adjusted odds ratio [OR], 0.85; 95%CI, 0.74–0.98) and obese (adjusted OR, 0.62; 95%CI, 0.49–0.79) patients had a significantly lower success rate on the first attempt. Additionally, obesity was significantly associated with a higher risk of adverse events (adjusted OR, 1.62; 95%CI, 1.23–2.13). Based on the data from a multicenter prospectively study, obesity was associated with a lower success rate on the first intubation attempt and a higher risk of adverse event in the ED.