Investigation into the clinical performance of rectus sheath block in reducing postoperative pain following surgical intervention: A systematic review and meta-analysis of randomised controlled trials

Background and aims: Rectus sheath block (RSB) is an effective postoperative pain control technique in abdominal surgical procedures. This systematic review evaluated the efficacy and outcome data of patients undergoing RSB compared to the standard of care in both laparoscopic and open surgical procedures.

Methods: This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PROSPERO ID: CRD42022372596). The search was restricted to randomised controlled trials (RCTs) comparing RSB effectiveness on postoperative pain to any standard general anaesthesia technique (control). We systematically explored PubMed, Medline, Central, Scopus and Web of Science for RCTs from inception to September 2023. The primary outcome was the evaluation of pain scores at rest 0-2, 10-12 and 12-24 h postoperatively. The secondary outcome was the analysis of postoperative intravenous (IV) morphine equivalent consumption at 24-h. A risk-of-bias tool for randomised trials (ROB 2.0, Cochrane, Copenhagen, Denmark) assessment and Grades of Recommendation, Assessment, Development and Evaluation (GRADE, Cochrane, Copenhagen, Denmark) analysis was conducted to evaluate the quality of the RCTs.

Results: Twenty RCTs involving 708 participants who received RSB intervention and 713 who received alternative analgesic care were included. RSB pain scores were significantly lower than control at 0-2 h (P < 0.001) and 10-12 h (P < 0.001) postoperatively. No significant effect was observed at 24 h (P = 0.11). RSB performance compared to control in 24-h IV morphine equivalency in milligrams was significantly lower (P < 0.001).

Conclusion: RSB implementation was associated with reduced postoperative pain scores and decreased opioid consumption in IV morphine equivalency up to 24 h following surgical intervention.