Intrathecal Morphine following Lumbar Fusion: A Randomized, Placebo-Controlled Trial

Abstract

BACKGROUND: Despite the potential for faster postoperative recovery and the ease of direct intraoperative injection, intrathecal morphine is rarely provided in lumbar spine surgery. OBJECTIVE: To evaluate the safety and efficacy of intrathecal morphine following lumbar fusion. METHODS: We randomly assigned 150 patients undergoing elective instrumented lumbar fusion to receive a single intrathecal injection of morphine (0.2 mg) or placebo (normal saline) immediately prior to wound closure. The primary outcome was pain on the visual-analogue scale during the first 24 h after surgery. Secondary outcomes included respiratory depression, treatment-related side effects, postoperative opioid requirements, and length of hospital stay. An intention-to-treat, repeated-measures analysis was used to estimate outcomes according to treatment in the primary analysis. RESULTS: The baseline characteristics of the 2 groups were similar. Intrathecal morphine reduced pain both at rest (32% area under the curves [AUCs] difference, P