Anterior Quadratus Lumborum Block at Lateral Supra-Arcuate Ligament vs Lateral Quadratus Lumborum Block for Postoperative Analgesia after Laparoscopic Colorectal Surgery: A Randomized Controlled Trial

<bold>Background: </bold>Quadratus lumborum block (QLB) has been found to be advantageous for laparoscopic colorectal surgery. This study hypothesized that preoperative anterior QLB at lateral supra-arcuate ligament (QLB-LSAL) would decrease postoperative opioid usage and offer improved analgesia within the context of multimodal analgesia compared with lateral QLB (LQLB) for laparoscopic colorectal surgery.<bold>Study design: </bold>In this randomized controlled trial, 82 American Society of Anesthesiologists physical status I to III class colorectal cancer patients undergoing laparoscopic radical resection were enrolled and randomly assigned to receive either LQLB or QLB-LSAL (0.375% ropivacaine 0.3 mL/kg bilaterally for each group). The primary outcomes were the total intravenous morphine equivalent consumption at 24 hours postoperatively.<bold>Results: </bold>Intravenous morphine equivalent consumption at 24 hours postoperatively was significantly reduced in the QLB-LSAL group compared with that in the LQLB group with per-protocol analysis (29.2 +/- 5.8 vs 40.5 +/- 9.6 mg, p < 0.001) and intention-to-treat analysis (29.6 +/- 6.1 vs 40.8 +/- 9.5 mg, p < 0.001). Time to first patient-controlled analgesia request was notably longer in the QLB-LSAL group than that in the LQLB group (10.4 +/- 3.9 vs 3.7 +/- 1.5 hours, p < 0.001).<bold>Conclusions: </bold>Preoperative bilateral ultrasound-guided QLB-LSAL reduces morphine usage and extends the duration until the first patient-controlled analgesia demand within the framework of multimodal analgesia when compared with LQLB after laparoscopic colorectal surgery.