Obstructive Sleep Apnea Increases the Risk of Cardiopulmonary Adverse Events Associated with Ambulatory Colonoscopy Independent of Body Mass Index.

Background: The relationship between body mass index (BMI) and cardiopulmonary adverse events (CAEs) for ambulatory colonoscopy is unclear.

Aim: To assess the association of BMI and CAEs associated with ambulatory colonoscopy.

Methods: This is a retrospective cohort analysis of 418 patients who underwent outpatient colonoscopy at the Durham Veterans Affairs Medical Center categorized as normal/overweight (BMI < 30), obese (BMI 30-34), or morbidly obese (BMI ≥ 35). Adjusted logistic regression analyses were performed.

Results: At least one CAE occurred in 46.4% of patients (220 events, 72.7% were hypoxia). The rate of CAEs (BMI < 30: 43.8%, BMI 30-34: 48.0%, BMI ≥ 35: 50.6%, p = 0.53) and rate of hypoxia (BMI < 30: 34.8%, BMI 30-34: 40.9%, BMI ≥ 35: 43.2%, p = 0.32) were numerically higher for obese and morbidly obese patients, but not statistically significant. Obese (OR 1.10, 95% CI 0.70-1.73) and morbidly obese (OR 1.07, 95% CI 0.61-1.85) patients did not have an increased risk of CAEs after adjusting for age, ASA class, obstructive sleep apnea (OSA), and type of sedation. OSA was independently associated with an increased risk of CAEs (OR 1.71, 95% CI 1.09-2.74, p = 0.02) after adjusting for BMI, age, ASA class, and type of sedation.

Conclusion: OSA confers a higher risk of CAEs independent of BMI and sedation type. Consideration of undiagnosed OSA is recommended for appropriate pre-procedure risk stratification. While not statistically significant in this study, there may be clinically significant increased risks of CAEs and hypoxia for patient with BMI > 30 that require further evaluation with larger studies.