Can a Validated Sleep Apena Scoring System Predict Cardiopulmonary Events During Anesthesiolgist-Directed Propofol Sedation for Routine EGD and Colonoscopy? A Prospective Cohort Study

Abstract

Purpose: With the rise of anesthesiologist-directed propofol (ADPS) for routine EGD and colonoscopy, there is limited data on the risk for sedation related complications (SRC) in patients with undiagnosed obstructive sleep apnea (OSA). Undiagnosed OSA, which is linked to the increased prevalence of obesity, continues to rise in the United States. We attempted to identify the prevalence of OSA and subsequent risk factors for airway complications (AC) and SRC in patients undergoing ADPS for EGD and colonoscopy. Methods: We prospectively enrolled 243 patients who underwent routine EGD or colonoscopy with ADPS. Patients were screened with a previously validated questionnaire for OSA (STOP-BANG, SB) to identify patients at high risk (SB score >3, SB+) or low risk (SB score <3, SB-) for undiagnosed OSA. AC were defined as a chin lift, mask ventilation, placement of nasopharyngeal airway, bag mask ventilation, or endotracheal intubation. SRC included hypoxemia (SPO2<90%), hypotension (SBP<25% of baseline), or early procedure termination due to sedation. Other variables such as age, gender, BMI, history of pulmonary disease, total propofol dose, and use of opioids were also analyzed. In addition, multivariable logistic regression analysis was performed to assess factors associated with AC and SRC, separately. An automated stepwise variable selection method performed on 1,000 bootstrap samples was used to choose the models. Results: Mean age was 50.1 ± 16.2 years and 41% of patients were male. The prevalence of SB+ was 48.1%. The rates of hypoxemia (27.4% vs. 35.9%, P=0.16) and hypotension (42.9% vs. 48.7%, P=0.36) were similar between SB- and SB+ patients. A STOP-BANG score ≥ 3 was found not to be associated with occurrence of AC (OR:1.04; 95% CI:0.58,1.9) or SRC (OR:1.4; 95% CI:0.66,2.8) after adjusting for total and loading dose of propofol, BMI, smoking and age. Higher BMI was associated with higher AC (OR:1.07; 95% CI:1.02,1.1) and SRC (OR:1.06; 95% CI:1.01-1.1). Higher total propofol doses (OR:0.89; 95% CI:0.81,0.98) and loading propofol doses (OR 2.1; 95% CI:1.2,3.5) and smoking (OR: 2.8;95% CI:1.4,5.3) were also associated with increased SRC. Conclusion: A significant number of patients undergoing routine EGD and colonoscopy under ADPS are at risk for OSA. STOP-BANG positive patients are not at higher risk for AC or SRC. However, other risk factors for AC and SCR have been identified and must be taken into account to optimize patient safety.