Quadratus lumborum block versus transversus abdominis plane block for postoperative analgesia in patients undergoing abdominal surgeries: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Abdominal surgery is common and is associated with severe postoperative pain. The transverse abdominal plane (TAP) block is considered an effective means for pain control in such cases. The quadratus lumborum (QL) block is another option for the management of postoperative pain. The aim of this study was to conduct a meta-analysis and thereby evaluate the efficacy and safety of QL blocks and TAP blocks for pain management after abdominal surgery.

METHODS: We comprehensively searched PubMed, EMBASE, EBSCO, the Cochrane Library, Web of Science and CNKI for randomized controlled trials (RCTs) that compared QL blocks and TAP blocks for pain management in patients undergoing abdominal surgery. All of the data were screened and evaluated by two researchers. RevMan5.3 was adopted for the meta-analysis.

RESULTS: A total of 8 RCTs involving 564 patients were included. The meta-analysis showed statistically significant differences between the two groups with respect to postoperative pain scores at 2 h (standardized mean difference [Std.MD] = - 1.76; 95% confidence interval [CI] = - 2.63 to - 0.89; p < .001), 4 h (Std.MD = -0.77; 95% CI = -1.36 to - 0.18; p = .01),6 h (Std.MD = -1.24; 95% CI = -2.31 to - 0.17; p = .02),12 h (Std.MD = -0.70; 95% CI = -1.27 to - 0.13; p = .02) and 24 h (Std.MD = -0.65; 95% CI = -1.29 to - 0.02; p = .04); postoperative morphine consumption at 24 h (Std.MD = -1.39; 95% CI = -1.83 to - 0.95; p < .001); and duration of postoperative analgesia (Std.MD = 2.30; 95% CI = 1.85 to 2.75; p < .001). There was no statistically significant difference between the two groups with regard to the incidence of postoperative nausea and vomiting (PONV) (RR = 0.55;95% CI = 0.27 to 1.14;p = 0.11).

CONCLUSION: The QL block provides better pain management with less opioid consumption than the TAP block after abdominal surgery. In addition, there are no differences between the TAP block and QL block with respect to PONV.