Inclusion Criteria:  Patients who indicated in upper gastrointestinal endoscopy and undergoing endoscopy at Excellence Center For GI Endoscopy, King Chulalongkorn Memorial Hospital, Thailand Age of 18 years or more  Exclusion Criteria:  Patients with a high risk of conscious sedation who need an anesthetist Patients with refusal to participate in clinical research Patients who cannot make medical decisions on their own