Postoperative intravenous morphine consumption, pain scores, and side effects with perioperative oral controlled-release oxycodone after lumbar discectomy.

Background: Oral opioid formulations contribute to postoperative analgesia. In this study, we evaluated the perioperative application of oral controlled-release oxycodone to reduce postoperative IV morphine consumption and opioid side effects after lumbar discectomy.
Methods: Forty patients scheduled for elective lumbar discectomy over 1 or 2 levels were included in this prospective, randomized, double-blind, placebo-controlled study. Every 12 h patients received either 20 mg oral controlled-release oxycodone or placebo, from the evening before surgery until the second postoperative morning. All patients received IV morphine via a morphine patient-controlled analgesia device for postoperative analgesia. Acetaminophen 1 g was administered to all patients every 6 h. Postoperative IV morphine consumption was assessed separately for T(0)-T(24) and T(24)-T(48). Postoperative assessments were conducted every 6 h for the first 48 h after surgery. Postoperative analgesia assessments included pain at rest, during coughing, and with motion, using a visual analog scale. Nausea, vomiting, pruritus, sedation, and bowel function were also assessed every 6 h. Patients rated their satisfaction with postoperative analgesia 72 h postoperatively.
Results: Postoperative IV morphine consumption was significantly reduced during T(0)-T(24) (26 +/- 10 mg vs 52 +/- 29 mg) and T(24)-T(48) (13 +/- 8 mg vs 33 +/- 18 mg) in the controlled-release oxycodone group compared with that in the placebo group. Pain scores at rest, during coughing, and with motion were significantly lower during the first 48 postoperative hours in the controlled-release oxycodone group. Postoperative nausea and vomiting were significantly reduced during the first 24 h in the controlled-release oxycodone group. Lastly, the controlled-release oxycodone group also experienced significantly earlier recovery of bowel function and had higher patient satisfaction with pain therapy.
Conclusions: Perioperative oral controlled-release oxycodone reduces postoperative IV morphine consumption after lumbar discectomy while providing good analgesia with fewer side effects compared with placebo.