Quadratus lumborum block vs. transversus abdominis plane block for postoperative pain control in patients with nephrectomy: A systematic review and network meta-analysis

Study objective: This systematic review and network meta-analysis aimed to compare the analgesic efficacy of transversus abdominis plane block (TAPB) and quadratus lumborum block (QLB) on nephrectomy. Design: Systematic review and network meta-analysis. Patients: Patients undergoing nephrectomy. Interventions: TAPB and QLB for postoperative analgesia. Measurements: The primary outcome was 24 h morphine-equivalent consumptions after surgery. Secondary outcomes included postoperative pain scores, postoperative opioid consumption, postoperative rescue analgesia, postoperative nausea and vomiting (PONV), length of hospital stay after surgery, and patient satisfaction. Main results: Fourteen studies involving 883 patients were included. Seven studies compared TAPB to control, six studies compared QLB to control, and one study compared TAPB to QLB. For direct meta-analysis of the post-surgical 24 h morphine-equivalent consumption, QLB was lower than control (mean difference [95%CI]: -18.16 [-28.96, -7.37]; I-2 = 88%; p = 0.001), while there was no difference between TAPB and control (mean difference [95%CI]: -8.34 [-17.84, 1.17]; I-2 = 88%; p = 0.09). Network meta-analysis showed similar findings that QLB was ranked as the best anesthetic technique for reducing postoperative 24 h opioid consumption (p-score = 0.854). Moreover, in direct meta-analysis, as compared to control, the time of first postoperative rescue analgesia was prolonged after QLB (mean difference [95%CI]: 165.00 [128.99, 201.01]; p < 0.00001), but not TAPB (mean difference [95%CI]: 296.82 [-91.92, 685.55]; p = 0.13). Meanwhile, QLB can effectively reduce opioid usages at intraoperative period, as well as at postoperative 6 h and 48 h, while TAPB can only reduce opioid consumption at 6 h after surgery. As compared to control, both TAPB and QLB exhibited the reduction in PONV and pain scores at post-surgical some timepoints. Also, QLB (mean difference [95%CI]: -0.29 [-0.49, -0.08]; p = 0.006) but not TAPB (mean difference [95%CI]: 0.60 [-0.25, 1.45]; p = 0.17) exhibited the shorter postoperative length of hospital stay than control. Conclusions: QLB is more likely to be effective in reducing postoperative opioid use than TAPB, whereas both of them are superior to control with regard to the reduction in postoperative pain intensity and PONV. Trial registration: PROSPERO identifier: CRD42022358464.