Epidural morphine provides postoperative pain relief in peripheral vascular and orthopedic surgical patients: a dose-response study.
A randomized double-blind study compared the dose-response relationship of epidural morphine for postoperative pain relief in two groups of patients whose surgical procedures would result in either moderate (femoral-popliteal bypass) or severe (total knee replacement) postoperative pain. Preservative-free morphine sulphate in doses of 0, 2, 5, or 10 mg in a volume of 10 ml saline were administered via lumbar epidural catheters. The epidural morphine was administered 1 hr after the last dose of intraoperative local epidural anesthetic in an effort to achieve a pain-free postoperative course. A significant relationship existed between the dose of epidural morphine and both time to first required pain medication and 24-hr weighted pain score. Five mg epidural morphine provided significant improvement in postoperative analgesia compared with the control in both groups. Further enhancement of analgesia occurred with 10 mg; however, late respiratory depression, demonstrated by an increased resting PaCO2 10 hr after administration, was seen only with the 10-mg dose in both surgical groups. Minor complications such as nausea, vomiting, pruritus, and urinary retention were uncommon and did not appear to be related to dose. We found that 5 mg epidural morphine provided long-lasting postoperative analgesia without serious adverse effects after peripheral vascular and orthopedic surgery.
D000328:Adult; D000368:Aged; D004305:Dose-Response Relationship, Drug; D004824:Epidural Space; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage* / Q000009:adverse effects; D009985:Orthopedics; D010149:Postoperative Pain / Q000188:drug therapy*; D012119:Respiration / Q000187:drug effects; D014656:Vascular Surgical Procedures
D009020:Morphine