Background and Aims 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 is still elusive. Therefore, we conducted this network meta-analysis to compare and rank the different injection sites for QLB for pain-related outcomes after CD.

Methods PubMed, EMBASE, SCOPUS, and the Cochrane Central Registers of Controlled Trials (CENTRAL) were searched for randomized controlled trials 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 endpoints were early pain scores (4-6 hours), late pain scores (24 hours), adverse effects, and block-related complications. We used surface under cumulative ranking (SUCRA) probabilities to order approaches. The analysis was performed using Bayesian statistics (random-effects model).

Results Thirteen trials enrolling 890 patients were included. The SUCRA probability for parenteral morphine equivalent consumption 24 hours was 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 PONV reduction, the only consistent reported side effect.

Conclusions 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.