Combination of intrathecal morphine and remifentanil infusion for fast-track anesthesia in off-pump coronary artery bypass surgery

Abstract

Objective: The purpose of this study was to assess the combination of intrathecal morphine and remifentanil infusion with isoflurane in off-pump coronary artery surgery, with a focus on postoperative analgesia and fast-tracking. Design: Prospective, randomized, controlled, blinded clinical study. Setting: University hospital. Participants: Forty-six patients who underwent elective off-pump coronary artery bypass grafting. Interventions: Patients were randomly assigned to receive remifentanil infusion alone (control group, n=23) or remifentanil infusion plus 10 mu g/kg of intrathecal morphine (ITM group, n=23). Induction and maintenance anesthesia were the same in both groups. Maintenance therapy was remifentanil infusion (0.25-1 mu g/kg/min) and 0.5% to 1.5% isoflurane, with adjustments according to hemodynamics. After extubation, intravenous patient-controlled analgesia with morphine (1-mg bolus and 5-minute lockout) was administered, and Wilson sedation scores, visual analog pain scores (scale, 0-100 mm) at rest and during coughing, and cumulative morphine consumption were assessed at 1, 2, 4, 8,12,24, and 48 hours. Examiners were unaware of patients' group identities. Anesthetic recovery parameters and opioid-related, spinal anesthesia-related, and cardiac complications were recorded. Measurements and Main Results: There were no differences between the groups' intraoperative hemodynamic or anesthetic recovery findings. Pain scores and morphine consumption were significantly lower in the ITM group at all time points after extubation (p=0.0001-0.05). Group frequencies of opioid-related and cardiac complications were similar. No patient had central neuroaxial hematoma or post-spinal tap headache. Conclusion: In the setting of isoflurane anesthesia for off-pump coronary artery bypass grafting, ITM combined with remifentanil infusion provides better postoperative analgesia than does remifentanil infusion alone, and does not improve or negatively affect fast-tracking.