A Randomised Controlled Trial on Analgesic Effect of Repeated Quadratus Lumborum Block Versus Continuous Epidural Analgesia Following Laparoscopic Nephrectomy

Abstract Background Epidural analgesia as the pain management for abdominal surgery has side effects such as paraesthesia, hypotension, haematomas, and impaired motoric of lower limbs. The quadratus lumborum block (QLB) has potential as an abdominal truncal block, however, the analgesic efficacy of QLB compared to epidural analgesia is unknown. This prospective randomised controlled study compared the effectiveness of QLB on postoperative opioid requirement and pain intensity with the epidural analgesia technique in transperitoneal laparoscopic nephrectomy. Methods Sixty-two patients underwent laparoscopic donor nephrectomy were randomised to receive QLB (n=31) or continuous epidural (n=31). The QLB group received bilateral QLB with 0.3–0.4 ml/kg bupivacaine 0.25% and the epidural group received bupivacaine 0.25% 6 ml/h for intraoperative analgesia. As postoperative analgesia, the QLB group received repeated bilateral QLB and the epidural group received the decreased dosage of bupivacaine 0.125% 6 ml/h for 24 hours after surgery completion. The primary outcome was cumulative morphine requirement 24 hours postoperatively. Secondary outcomes included haemodynamic changes, postoperative pain scores, sensory block coverage, Bromage score, postoperative nausea and vomiting (PONV), and duration of urinary catheterisation. Result Postoperative cumulative morphine requirement, pain scores, PONV and Bromage score were not significantly different between the QLB and epidural group. The QLB affected T9–L2, continuous epidural block affected T8–L3 dermatomes. Duration of urinary catheterisation was shorter (p < 0.001) in the QLB group. The mean arterial pressure (MAP) measured at 24 hours after surgery was lower in the epidural group (p = 0.001). Conclusion The repeated QLB had similar cumulative 24-hour morphine requirement, higher MAP, similar postoperative pain scores, similar PONV and degree of motor and sensory blockade, and shorter urinary catheterisation duration, compared with continuous epidural analgesia after transperitoneal laparoscopic nephrectomy. Trial Registration ClinicalTrial.gov NCT03520205 retrospectively registered on May 9th 2018. Keywords: epidural analgesia; laparoscopic nephrectomy; postoperative analgesia; patient-controlled analgesia; quadratus lumborum block.