Comparison of analgesic effects of morphine, fentanyl, and remifentanil with intravenous patient-controlled analgesia after cardiac surgery

OBJECTIVE: The purpose of this study was to compare the analgesic effects of remifentanil with 2 other opioid agents, morphine and fentanyl, after cardiac surgery. DESIGN: Prospective, randomized, and double-blinded study. SETTINGS: This study was performed at Uludag University hospital. PARTICIPANTS: Seventy-five patients undergoing off-pump coronary artery bypass surgery were included in the study. INTERVENTIONS: Anesthesia was standardized. Cases were randomized into 3 groups consisting of 25 patients in each. Groups M, F, and R were given morphine HCl (1 mg/mL) with an infusion rate of 0.3 mg/h and 1-mg bolus doses; fentanyl (50 microg/mL) with an infusion rate of 1 microg/kg/h and 10-microg bolus; and, remifentanil (50 microg/mL) with an infusion rate of 0.05 microg/kg/min and 0.5-microg/kg bolus, respectively. Continuous infusion was started immediately after the completion of the surgery. MEASUREMENTS AND MAIN RESULTS: Pain was assessed by using a visual analog scale (0-10), and sedation was assessed with the Ramsey sedation score (1-6) 30 minutes, 1, 2, 4, 12, and 24 hours after extubation. The number of boluses and demands, time to extubation, and side effects were analyzed. Visual analog scale, sedation scores, and mean extubation times were similar in all groups. Total number of boluses and demands were statistically more in the remifentanil group. Regarding the side effects, nausea and vomiting was higher in group M (p < 0.05), whereas itching was prominent in group F (p < 0.05). CONCLUSIONS: Despite the different durations of these 3 opioid agents, the infusion dose of remifentanil was as effective as morphine and fentanyl after OPCAB surgery with fewer side effects.