The effect of epidural vs intravenous analgesia for posterior spinal fusion surgery

The study objective was to compare epidural vs intravenous postoperative analgesia in posterior spinal fusion surgery patients.

This prospective, double-blinded, randomized study was performed in a tertiary care teaching hospital involving 31 American Society of Anesthesiologists physical status I and II adolescent/young adult patients scheduled for elective posterior spinal fusion surgery for idiopathic scoliosis. Patients were divided into three treatment groups according to the epidural solution infused: group 1 (n = 10) 0.1% bupivacaine + 5 microg x ml(-1) fentanyl; group 2 (n = 12) 0.0625% bupivacaine + 5 microg x ml(-1) fentanyl; group 3 (n = 9) 0.9% sodium chloride (placebo). During general anesthesia all patients received a directly placed midthoracic epidural catheter with a set infusion rate followed by morphine sulfate intravenous patient-controlled analgesic device postoperatively. Morphine sulfate usage and visual analog scores were evaluated at 4 h intervals postoperatively for up to 96 h. Postoperative time to liquids, solid food, ambulation, length of stay, discontinuation of Foley catheter, and side effects were recorded.

No consistent difference was detected on intravenous morphine dose usage, visual analog scores, or estimated pain scale over the whole follow-up period. No difference was observed in the epidural groups in time to oral intake of liquids or solids, ambulation, bowel sounds, or length of stay when compared with placebo.

By evaluating morphine sulfate usage between groups, the analgesic effectiveness of continuous thoracic epidural analgesia bupivacaine and fentanyl doses used revealed no significant improvement over intravenous morphine sulfate analgesia alone in patients after posterior spinal fusion surgery.