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

Background: 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.

Methods: 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.

Results: 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.

Conclusions: 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.

Clinical trial registration: PROSPERO Registration Number: CRD42021269044.

Keywords: acute postoperative pain; fascial plane blocks; midline laparotomy; network meta-analysis; regional anaesthesia.