Efficacy of Different Approaches of Quadratus Lumborum Block for Postoperative Analgesia After Cesarean Delivery: A Bayesian Network Meta-analysis of Randomized Controlled Trials

Objectives: Various approaches to quadratus lumborum block (QLB) have been found to be an effective analgesic modality after cesarean delivery (CD). However, the evidence for the superiority of any individual approach still needs to be demonstrated. Therefore, we conducted this network meta-analysis to compare and rank the different injection sites for QLB for pain-related outcomes after CD. Materials and Methods: PubMed, EMBASE, SCOPUS, and the Cochrane Central Registers of Controlled Trials (CENTRAL) were searched for randomized controlled trials (RCTs) evaluating the role of any approach of QLB with placebo/no block for post-CD pain. The primary outcome was parenteral consumption of morphine milligram equivalents in 24 postoperative hours. The secondary end points were early pain scores (4 to 6 h), late pain scores (24 h), adverse effects, and block-related complications. We used the surface under cumulative ranking probabilities to order approaches. The analysis was performed using Bayesian statistics (random-effects model). Results: Thirteen trials enrolling 890 patients were included. The surface under cumulative ranking probability for parenteral morphine equivalent consumption in 24 hours was the highest (87%) for the lateral approach, followed by the posterior and anterior approaches. The probability of reducing pain scores at all intervals was highest with the anterior approach. The anterior approach also ranked high for postoperative nausea and vomiting reduction, the only consistent reported side effect. Discussion: The anterior approach QLB had a superior probability for most patient-centric outcomes for patients undergoing CD. The findings should be confirmed through large RCTs.