Propofol is one of the most commonly used sedative in endoscopic procedures, while its potency to induce respiratory depression may threaten patient safety. Remimazolam is known to less likely induce hemodynamic instability when compared to propofol, yet its favorable effects are not clearly evaluated in endoscopic procedures. Hence, this study aimed to compare hemodynamic effects of remimazolam and propofol, by evaluating oxygen reserve index (ORI) in patients scheduled for endoscopic retrograde cholangiopancreatography.

Inclusion Criteria:

• Patients (age 19~80 yrs, ASA Class I~III) who are scheduled for elective endoscopic retrograde cholangiopancreatograph

Exclusion Criteria:

• Pregnancy Allergy to remimazolam or propofol Underlying pulmonary diseases or obstructive sleep apnea Underlying renal (serum Cr >2mg/dL) or cardiac disease (NYHA class III or IV) Hypotension (SBP <90mmHg) or hypoxemia (SpO2 <90%) assessed prior to procedure