Comparison of Intraoperative Infusion of Remifentanil Versus Fentanyl on Pain Management in Patients Undergoing Spine Surgery: A Double Blinded Randomized Clinical Trial

BACKGROUND: Remifentanil is an ultra-short-acting opioid which facilitates hemodynamic management. However, there are concerns about postoperative Remifentanil hyperalgesia because of its potent fast onset and offset. OBJECTIVES: The aim of this study was to determine visual analog scale (VAS), postoperative pain, and morphine used in two groups after spine surgery. METHODS: In this randomized clinical trial study, 60 patients aged 18 - 60 years old, according to the American Society of Anesthesiology (ASA) I - II, who underwent spinal canal stenosis or scoliosis surgery, were divided into two groups. In the control group, patients received 0.07 - 0.1 µg/kg/h intraoperative Fentanyl infusion, and in the intervention group 0.1 - 0.2 µg/kg/min remifentanil was infused during the surgery. Both groups received 15 mg/kg intravenous Acetaminophen 20 minutes before the end of the surgery. Postoperative pain score and morphine consumption were measured 6, 12, 24, and 48 hours after discharge from the post-anesthesia care unit (PACU). RESULTS: During the first 12 hours, VAS and morphine consumption were significantly higher in remifentanil group (P < 0.001). However, no significant difference was found between the two groups in morphine consumption 12 - 48 hours after surgery. CONCLUSIONS: These findings suggest that Remifentanil infusion during surgery may increase postoperative pain. Also, VAS and morphine consumption were higher during the first 12 hours.