Moderate Sedation for Elective Upper Endoscopy With Balanced Propofol Versus Propofol Alone: a Randomized Clinical Trial

Inclusion Criteria: 1. over 19 years old, male and female 2. patients who have plan to get esophagogastroduodenoscopy (EGD) Exclusion Criteria: 1. ASA class III or IV 2. Allergies to propofol, sulfites or eggs 3. patients who had surgery for esophagus, stomach or duodenum 4. inpatients 5. patients who had sleep apnea, gastroparesis or achalasia 6. patients who are taking sedative drugs more than 6 months 7. pregnancy 8. hypotension (systolic pressure less than 90mmHg), bradycardia (pulse rates less than 50 times per minute) or hypoxia (SpO2 less than 90%) 9. psychiatric or neurologic problems (ex. epilepsy or dementia)