Quadratus lumborum block for postoperative analgesia after cesarean delivery: A systematic review with meta-analysis and trial-sequential analysis

Study objective: The aim of this study was to investigate the analgesic efficacy of Quadratus lumborum block (QLB) versus controls, transversus abdominis plane (TAP) block and neuraxial morphine, or when added to neuraxial morphine in women undergoing cesarean delivery. Design: Systematic review and meta-analysis with trial sequential analysis. Patients: Parturients undergoing cesarean delivery. Intervention: Quadratus lumborum block for postoperative analgesia. Measurements: The primary outcomes were dynamic and static pain scores and cumulative opioid consumption at 24 h. Secondary outcomes were dynamic and static pain scores and opioid consumption at 6 and 12 h. Certainty of evidence was assessed using the GRADE system. Trial sequential analyses (TSA) were performed to determine if the results are supported by sufficient data. Main results: Ten studies involving 761 parturients were included. Compared to controls, no difference in dynamic (MD-6; 95%CI-17 to 5) or static (MD-5; 95%CI-14 to 3) pain scores were noted with QLB at 24 h (moderate certainty), although opioid consumption (MD -10.64 mg morphine equivalents; -16.01 to -5.27) was reduced (high certainty), supported by sufficient data. QLB reduced dynamic pain at 6 h, and static pain and opioid consumption at 6 and 12 h compared to controls. Compared to neuraxial morphine, QLB did not alter opioid consumption or pain scores at 24 h (low certainty), although TSA suggests insufficient data. Due to limited data, meta-analysis and TSA were not performed to compare QLB and TAP blocks. Addition of QLB to neuraxial morphine did not alter dynamic and static pain scores at 24 h (moderate certainty, supported by sufficient data) Conclusions: QLB improves post-cesarean delivery analgesia in parturients not receiving neuraxial morphine. Addition of QLB to parturients receiving neuraxial morphine has no significant analgesic benefit. Insufficient data are available to draw firm conclusions of QLB compared to TAP blocks or neuraxial morphine.