Abstract and Introduction

Abstract

Study Design. Meta-analysis of randomized controlled trials (RCTs).

Objective. The aim of this study was to evaluate the effectiveness of intrathecal morphine (ITM) in reducing postoperative pain and opioid analgesic consumption following spine surgery.

Summary of Background Data. The use of ITM following adult spine surgery is of particular interest because of the ease of access to the thecal sac and the potential to provide adequate analgesia at low doses. However, previous studies of ITM have been limited by small sample sizes and conflicting results.

Methods. A comprehensive search of PubMed, Web of Science, Clinicaltrials.gov, and the Cochrane Central Register of Controlled Trials for prospective RCTs was performed by two independent reviewers. Postoperative opioid consumption, pain scores, and complications were documented from the identified studies. Standard mean differences (SMDs) were applied to continuous outcomes and odds ratios were determined for dichotomous outcomes.

Results. Eight RCTs involving 393 subjects met inclusion criteria and were included in this meta-analysis. Patients receiving ITM (ITM group) as an adjunct to postoperative opioid analgesic were compared to patients receiving postoperative opioids only (control group). Postoperative morphine equivalent consumption was significantly lower during the first 24 hours postoperative in the ITM group (P < 0.001). Pain scores were similarly lower in the first 24 hours following spine surgery in those who received ITM (P < 0.001). In patients administered ITM, a greater percentage experienced pruritus (P < 0.001). Respiratory depression was solely encountered in the ITM group (P = 0.25). There were no significant differences between the ITM and control groups in terms of sedation (P = 0.18), nausea (P = 0.67), vomiting (P = 0.62), or length of stay (P = 0.13).

Conclusion. In patients undergoing spine surgery, use of ITM significantly reduced opioid analgesic consumption and Visual Analogue Schores pain scores compared to controls within the first 24 hours postoperatively. High-quality, follow-up RCTs with large sample sizes are recommended to determine the potential of supplementary ITM in spine surgery and complete the side effects profile.