Comparative efficacy and safety of non-neuraxial analgesic techniques for midline laparotomy: a systematic review and frequentist network meta-analysis of randomised controlled trials.

Abstract

Fascial plane blocks provide effective analgesia after midline laparotomy; however, the most efficacious technique has not been determined. We conducted a systematic review and network meta-analysis of randomised controlled trials to synthesise the evidence with respect to pain, opioid consumption, and adverse events. We searched Ovid MEDLINE, Embase, Cochrane Central, and Scopus databases for studies comparing commonly used non-neuraxial analgesic techniques for midline laparotomy in adult patients. The co-primary outcomes of the study were 24-h cumulative opioid consumption and 24-h resting pain score, reported as i.v. morphine equivalents and 11-point numerical rating scale, respectively. We performed a frequentist meta-analysis using a random-effects model and a cluster-rank analysis of the co-primary outcomes. Of 6115 studies screened, 67 eligible studies were included (n=4410). Interventions with the greatest reduction in 24-h cumulative opioid consumption compared with placebo/no intervention were single-injection quadratus lumborum block (sQLB; mean difference [MD] -16.1 mg, 95% confidence interval [CI] -29.9 to -2.3, very low certainty), continuous transversus abdominis plane block (cTAP; MD -14.0 mg, 95% CI -21.6 to -6.4, low certainty), single-injection transversus abdominis plane block (sTAP; MD -13.7 mg, 95% CI -17.4 to -10.0, low certainty), and continuous rectus sheath block (cRSB; MD -13.2 mg, 95% CI -20.3 to -6.1, low certainty). Interventions with the greatest reduction in 24-h resting pain score were cRSB (MD -1.2, 95% CI -1.8 to -0.6, low certainty), cTAP (MD -1.0, 95% CI -1.7 to -0.2, low certainty), and continuous wound infusion (cWI; MD -0.7, 95% CI -1.1 to -0.4, low certainty). Clustered-rank analysis including the co-primary outcomes showed cRSB and cTAP blocks to be the most efficacious interventions. Based on current evidence, continuous rectus sheath block and continuous transversus abdominis plane block were the most efficacious non-neuraxial techniques at reducing 24-h cumulative opioid consumption and 24-h resting pain scores after midline laparotomy (low certainty). Future studies should compare techniques for upper vs lower midline laparotomy and other non-midline abdominal incisions. PROSPERO Registration Number: CRD42021269044.