This study aimed to compare the efficacy of ketamine and propofol mixture with 1:6 ratio and 1:4 ratio for endoscopic retrograde procedure

Approval from Ethical Committee of Faculty of Medicine Universitas Indonesia was acquired prior conducting the study. Subjects were given informed consent before enrolling the study. Intravenous (IV) cannula (20 G) , non-invasive blood pressure monitor, and pulse-oxymetry had been set on the subjects in endoscopic room. Vital signs were recorded. Subjects were then randomized into two groups (Ketamine:propofol ratio of 1:6 [K16] and ketamine:propofol ratio of 1:4 [K14]). K16 group's drug mixture was ketamine:propofol with ratio of 1:6, filled in 50 cc syringe, which consisted of 1 ml of ketamine (50 mg/ml), 30 ml of 1% propofol (10 mg/ml), and 19 ml of normal saline so that every ml of mixture consisted of 1 mg of ketamine and 6 mg of propofol. K14 group's drug mixture was ketamine:propofol with ratio of 1:4, filled in 50 cc syringe, which consisted of 1 ml of ketamine (50 mg/ml), 20 ml of 1% propofol (10 mg/ml), and 29 ml of normal saline so that every ml of mixture consisted of 1 mg of ketamine and 4 mg of propofol. Patient then was given initial bolus dose of 1 mg/kg body weight (BW) (based on propofol dose) and continued with maintenance dose of propofol (50 mcg/kg BW/minute, based on propofol dose). Maintenance dose could be increased by 10 mcg/kg BW/ minute if the subject still gave response to surgical stimulation or decreased by 10 mcg/kg BW/minute if hypotension occured. Onset of the drug, vital signs every 5 minutes, hypotension and desaturation events were recorded. If there were signs of pain such as tachycardia or hypertension, an additional dose of 25 mcg of fentanyl intravenous was given and recorded. After the endoscopic retrograde cholangiopancreatography (ERCP) finished, drugs were stopped and the total doses of propofol, drug administration speed, total dose of fentanyl used, and recovery time were recorded. Subjects were moved to the recovery room and observed for side effects event. Subjects were moved to the ward after aldrete score of 9-10.

Inclusion Criteria:

• Patients who were going to undergo ERCP unders sedation. Patient with American Society of Anesthesiologists (ASA) physical status of I-III, and body mass index of 18-30 kg/m2.

Exclusion Criteria:

• Subjects with history of allergy with drugs used in this trial, subjects with cardiovascular disease, hypertension, respiratory disorder, pregnancy, unstable hemodynamic, psychiatric drugs consumption, possibility of difficult airway, and kidney disorder

Drop out Criteria:

• drug allergy during procedure, hypotension (>20%) not resolved using ephedrine, desaturation (oxygen saturation <90%) not resolved using positive pressure ventilation, and endoscopic complication occur