Comparison of remifentanil and alfentanil efficacy in sedation for colonoscopy

Patients aged over 18 years with ASA I-III who underwent colonoscopic examination for diagnosis and treatment under sedation with low dose of midazolam combined with Propofol/remifentanil and Propofol/alfentanil were included in the study. Patients aged under 18 years, having ASA IV-V and patients with opioid and/or sedative addictions, pregnancy, psychiatric/emotional disorder, patients undergoing an emergency or inpatient colonoscopy, and other endoscopic procedures in addition to colonoscopy were excluded from the study. Patients with incomplete procedure for any reason, and patients with inadequate bowel preparation were excluded from the final analysis. Two hundred patients who underwent colonoscopy under sedation with the combination of remifentanil-propofol-midazolam or alfentanil-propofol-midazolam were included in the study. Eleven patients were excluded from the final analysis. The age, gender, body mass index (BMI), and American Anesthesiology Association physical status classification (ASA) of one hundred eighty-nine patients were recorded. All colonoscopy procedures were performed by the same experienced endoscopist using high resolution video colonoscopies (EC-530WL3, Fujinon, Fujifilm Corporation, Japan). All patients were monitored according to the ASA standards in the colonoscopy room. Heart rate (HR), mean arterial pressure (MAP), and peripheral oxygen saturation (SpO2) were measured and recorded (Petas KMA 800). Measurements were repeated every 5 minutes during the procedure. Intranasal oxygen (6 L/min) was administered to the patients. After peripheral intravenous cannulation, 6 ml/kg/hr normal saline infusion was initiated and 1 mg midazolam (1 mg/ml, 5 ml; Deva Holding, Istanbul, Turkey) was administered to all patients. Sedation was induced with 5µcg/kg alfentanil (Rapifen® Johnson & Johnson, Istanbul, Turkey) + 1 mg/kg propofol (Propofol, Fresenius, Istanbul, Turkey) in the alfentanil group (Group A), and 0.1 µcg/kg/min remifentanil (Ultiva, Glaxo Smith Kline, Istanbul, Turkey) + 1 mg/kg propofol in the remifentanil group (Group R). Propofol (10-20 mg) was added according to the Modified Steward Scale (MSS) in order to maintain at 2-4 . Additional propofol doses were recorded. Pain level of the patients was assessed by visual analog scale (VAS) [no pain (0) - severe pain (10)] at every 5-minute interval during the colonoscopy procedure. Systolic blood pressure under 90 mmHg was accepted as hypotension and HR under 50 beats/min was accepted as bradycardia. Fluid infusion rate of patients who developed hypotension was increased by 3 folds. Additional fluid infusion was continued for 10 minutes. Vasopressor (ephedrine) administration was planned in patients who had no response to liquid infusion. Atropine (0.01 mg/kg; intravenous) was given to patients in case of bradycardia. SpO2 less than 90% was accepted as hypoxemia. When SpO2 was determined less than 90% during the follow up, jaw thrust maneuver was performed. If SpO2 persisted as less than 85% despite the jaw thrust maneuver, all of the infusions were stopped and assisted ventilation was performed. It was planned that, if SpO2 less than 85% took more than 30 seconds, then the procedure would be interrupted and an antagonist agent (flumazenil, naloxone) would be administered. Cardiopulmonary side effects (hypotension, bradycardia, and hypoxemia), nausea, vomiting, and the treatment were recorded in all patients. Colonoscopic procedure was waited for 60 seconds after the administration of the drugs. Total procedure time was defined as the time between the initiation and completion of colonoscopy. Awake time was defined as the time from the end of colonoscopy until Consciousness (0-4) score 4 according to the Modified Steward Scalasi (MSS), and the recovery time was defined as the time from the end of colonoscopy until Modified Aldrete Scoring (MAS) 10 was achieved. After the procedure, all patients were transferred to the recovery room and vital findings and MAS values were recorded. (MAS) which is a 10-point scale was used for assessing the recovery time . Patients were followed up until MAS 10 and then discharged.