Posteromedial quadratus lumborum block versus transversus abdominal plane block for postoperative analgesia following laparoscopic colorectal surgery: A randomized controlled trial

Abstract

Study objectiveOur hypothesis was that a pre-operative posteromedial quadratus lumborum (QL) block would reduce postoperative morphine consumption and provide superior analgesia in the setting of multimodal analgesia compared with a lateral transversus abdominis plane (TAP) block for laparoscopic colorectal surgery. DesignA randomized controlled study. SettingA single tertiary hospital. March to August 2018. Patients80 ASA I–II colorectal cancer patients undergoing laparoscopic radical resection were enrolled. 77 patients (group QL 38, group TAP 39) were included in the analysis. InterventionPre-operatively, patients were randomized to receive either a QL or TAP block (0.375% ropivacaine 20 ml bilaterally for each group). MeasurementsThe primary outcome was cumulative morphine consumption 24 h postoperatively. Secondary outcomes included postoperative pain scores, clinical recovery, and side-effect profiles of the blocks. Main resultsFor the primary outcome measure, morphine consumption 24 h postoperatively was significantly lower in the QL group than in the TAP group (estimated median difference −8 mg, adjusted 95% confidential interval −12 to −6 mg, P < 0.001). The pain visual analogue scores at rest and during movement were found to be statistically significantly lower in the QL group than in the TAP group 8, 12, and 24 h postoperatively (P < 0.006). The QL group reported higher overall satisfaction scores regarding postoperative analgesia than the TAP group (P = 0.014). One patient in the QL group experienced moderate back pain close to the needle entry site postoperatively. There was no statistically significant difference in postoperative nausea and vomiting, bowel recovery or length of hospital stay between the groups. ConclusionsThe pre-operative bilateral, ultrasound-guided posteromedial QL block reduces morphine consumption and improves analgesia in the setting of multimodal analgesia compared with the lateral TAP block after laparoscopic colorectal surgery.