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

BACKGROUND CONTEXT: Patients undergoing lumbar spinal surgery may experience consid- erable 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. PURPOSE: The current study evaluated the efficacy and safety of preemptive analgesia with intra- thecal morphine (ITM) in patients undergoing multilevel posterior lumbar spinal fusion surgery. STUDY DESIGN: Double -blinded, randomized, controlled trial. PATIENT SAMPLE: Ninety-two patients aged between 18 and 80 years who were scheduled to undergo elective lumbar laminectomy (L3 -S1) and dual -level fusions. OUTCOME MEASURES: 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. METHODS: 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. RESULTS: 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 with- out support. CONCLUSIONS: Preemptive analgesia with ITM results in significantly improved early postop- erative pain control and decreased postoperative patient -controlled intravenous analgesia consump- tion, with no increase in adverse effects. (c) 2020 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY -NC -ND license. (http://creativecommons.org/licenses/by-nc-nd/4.0/)