The prevalence of sleep-disordered breathing in Republic of Korea is 27% and 16% in men and women aged 40-69 years. Up to 93% of women and 82% of men with obstructive sleep apnea (OSA) remain undiagnosed. Polysomnography, the gold standard, is time consuming and costly. Patients with undiagnosed OSA may experience obstructive episodes during procedures with conscious sedation.

STOP-Bang questionnaire is the validated questionnaire to screen patients for undiagnosed OSA in the preoperative setting. It has high sensitivity (92.9%) for predicting patients with moderate to severe OSA.

Previous studies reported that STOP-Bang questionnaire predicted cardiopulmonary events during advanced endoscopic procedures such as endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound. However, there have been no studies regarding the risk for sedation-related cardiopulmonary events in patients with undiagnosed OSA undergoing bronchoscopy. Thus, we aimed to evaluate the prevalence of high-risk patients for OSA by a screening questionnaire, and to determine whether the questionnaire could predict patients who are at risk for cardiopulmonary events during bronchoscopy with conscious sedation.

Inclusion Criteria:

• Patients who are18 years or order undergoing bronchoscopy with conscious sedation in the bronchoscopy center

Exclusion Criteria:

• Previous diagnosis of OSA
• American Society of Anesthesiologists Physical Status Classification System score > 3
• Baseline SpO2 < 90% or need for supplemental oxygen before the procedure
• Tracheostomy tubes
• An inability to provide informed consent
• Undergoing the procedure based on an outpatient clinic
• Undergoing BAL, EBUS-TBNA, and interventional bronchoscopy
• Allergies or sensitivities to sedative medications
• Pregnant

Tertiary referral hospital