Comparison of efficacy of quadratus lumborum block and intrathecal morphine in elective caesarean section for postoperative analgesia – A randomised controlled trial

Background and Aims: As caesarean section (C-section) rates continue to rise, effective planning and management of postoperative pain become crucial. Poor control can delay early mobilisation and breastfeeding, and it also raises the risk of complications like thromboembolic events, postoperative ileus, and chronic pain development. This study aimed to compare the efficacy of postoperative analgesia between intrathecal morphine (ITM) and quadratus lumborum block (QLB) in the elective C-section. Methods: This prospective, double-blinded, randomised controlled trial included 60 women who underwent elective C-sections. The participants were randomly assigned to receive either ITM [0.1 ml (100 μg) of morphine] or bilateral QLB with 40 ml 0.375% ropivacaine. Both the ITM and QLB groups had received a subarachnoid block consisting of 2 ml of 0.5% hyperbaric bupivacaine with 0.1 ml of ITM or saline for a total of 2.1 ml. Postoperatively, pain score using the numerical rating scale (NRS), the need for rescue analgesia, and patient satisfaction score (0–10) were monitored for 48 h. Results: Out of the 60 parturients enroled, 59 were included in the final analysis (ITM n = 30, QLB n = 29). Postoperative pain scores assessed using the NRS were significantly lower in the ITM group than in the QLB group at 4, 8, 12, and 24 h after surgery ( P = 0.042). The time to first request for rescue analgesia was longer in the ITM group than in the QLB group (19.8 ± 10.3 h vs 9.2 ± 4.3 h; P < 0.001). Patients in the ITM group also reported higher patient satisfaction scores. No clinically significant adverse effects were observed in either group during the study period. Conclusion: Group ITM was associated with lower postoperative pain scores, longer-lasting analgesia, reduced need for rescue analgesics, and higher patient satisfaction compared with QLB after elective C-section, with no clinically significant adverse effects.