The Efficacy and Safety of Local Anesthetic Techniques for Postoperative Analgesia After Cesarean Section: A Bayesian Network Meta-Analysis of Randomized Controlled Trials

Objective: Cesarean section (CS) is one of the most frequently performed major surgical interventions. Local anesthetic techniques, a universal component of perioperative multi-modal analgesia, are reportedly effective in reducing pain scores and opioid requirements. However, the optimal local anesthetic technique for postoperative CS pain remains unclear. Methods: Six databases were searched, and a Bayesian network meta-analysis was performed. The outcomes included cumulative morphine consumption and pain scores at four time points, time to first analgesic request, postoperative nausea and vomiting, pruritus, and sedation. Results: Sixty-eight studies with 5039 pregnant women were included. Six local anesthetic techniques were involved, including transversus abdominis plane block (TAPB), ilioinguinal and iliohypogastric nerve block, quadratus lumborum blocks, transversalis fascia plane block, erector spinae block, and wound infiltration. Compared to inactive controls, TAPB reduced cumulative morphine consumption at 6, 12, 24, and 48 h, pain scores at 6, 12, and 24 h (with the exception of 24 h at rest), the risk of postoperative nausea and vomiting, and sedation. Compared with inactive controls, ilioinguinal and iliohypogastric nerve block reduced cumulative morphine consumption at 6 and 24 h and pain scores at 6, 12, and 24 h during movement. Compared with inactive controls, quadratus lumborum blocks reduced cumulative morphine consumption at 24 and 48 h and pain scores at 6 and 12 h and lengthened the time to first analgesic request. Compared with inactive controls, wound infiltration reduced cumulative morphine consumption at 12 and 24 h, pain scores at 12 and 24 h during movement, and risk of sedation. Compared with inactive controls, erector spinae block reduced pain scores at 6 and 12 h. Transversalis fascia plane block was found to have similar outcomes to inactive controls. Conclusion: TAPB is the most comprehensive local anesthetic technique for postoperative CS analgesia in the absence of intrathecal morphine.