Preemptive analgesia with a single low dose of intrathecal morphine in multilevel posterior lumbar interbody fusion surgery: a double-blind, randomized, controlled trial.

Abstract

Patients undergoing lumbar spinal surgery may experience considerable pain in the early postoperative period, and poor pain control after multilevel lumbar spinal fusion surgery is frequently associated with multiple complications and delayed discharge from hospital. The current study evaluated the efficacy and safety of preemptive analgesia with intrathecal morphine (ITM) in patients undergoing multilevel posterior lumbar spinal fusion surgery. Double-blinded, randomized, controlled trial. Ninety-two patients aged between 18 and 80 years who were scheduled to undergo elective lumbar laminectomy (L3-S1) and dual-level fusions. The primary endpoint was the degree of postoperative pain at rest and during movement evaluated using a 10-point visual analogue scale. The secondary outcomes included the consumption of analgesics, the patient-assessed postoperative and satisfaction scores, adverse effects, time to first ambulation, and length of hospital stay. Patients were randomly allocated to either the ITM group that received 0.2 mg of ITM or the control (CON) group that received 2 ml of 0.9% saline as a skin infiltration 30 minutes prior to anesthesia induction. The ITM group had a significantly lower visual analogue scale score than the CON group during the first 3 days postoperatively (at rest, P=0.000, during movement, P=0.000). The ITM group used significantly less sufentanil than the CON group in the first 3 days postoperatively (p=.000) in patient-controlled intravenous analgesia, as well as in supplemental analgesic demands. The ITM group reported a greater degree of satisfaction with the whole hospitalization experience than the CON group (2.4±0.6 vs. 1.9±0.6, p=.000). The two groups did not significantly differ regarding adverse effects, length of hospital stay, and time taken to regain the ability to walk without support. Preemptive analgesia with ITM results in significantly improved early postoperative pain control and decreased postoperative patient-controlled intravenous analgesia consumption, with no increase in adverse effects.