(1180) Does Obesity Affect the Risk of Post-Bronchoscopy Pneumothorax?

Introduction: Obesity (BMI≥30) is associated with an increased risk of postoperative complications, including myocardial infarction, wound infection, and pulmonary embolism. Pneumothorax, a known complication of bronchoscopy, exhibits a complex relationship with obesity. While some studies indicate a decreased risk in obese patients, undergoing procedures such as CT-guided lung biopsy and transbronchial biopsy, the overall association between obesity and pneumothorax following bronchoscopy remains uncertain.

Methods: This research investigated the risk of pneumothorax after bronchoscopy procedures in obese patients. Analyzing data from the National Inpatient Sample (2020), 230,620 adult patients, over the age of 18 years, were identified, who underwent bronchoscopy. The study aimed to compare this risk between patients with and without obesity, using both univariate and multivariable logistic regression were used to measure the risk of post-bronchoscopy pneumothorax in obese as compared to non-obese patients. Potential confounding like age, gender, underlying health conditions (Charlson Co-morbidity index), hospital location, region, and teaching status were adjusted in analysis.

Results: Out of the total of 230,620 adult patients who underwent bronchoscopy, 2.1% (4,680 patients) developed post-procedure pneumothorax. Furthermore, of the 230,620 patients, 16.67% (38,435 patients) had underlying obesity. Our findings revealed that the rate of post-procedure pneumothorax was significantly lower (OR 0.54 (0.43-0.66), p < 0.001) in obese patients compared to non-obese patients. The mean age of obese participants was 59 years (58.6-59.4). Fifty one percent (19,380 patients) of the obese patient population comprised of females.

Conclusions: This study underscores the potential protective role of obesity in reducing the incidence of pneumothorax following bronchoscopy. The underlying physiologic mechanism is not clear. One of the possible explanations is as follows. Obesity is associated with reduced pulmonary compliance, limiting lung expansion. This decreased lung distensibility may protect against alveolar rupture and subsequent pneumothorax. The complex relationship between obesity and pneumothorax requires further investigation.