Comparison of ultrasound-guided erector spinae plane block versus transmuscular quadratus lumborum block for postoperative analgesia after caesarean delivery: a prospective randomized non-inferiority clinical trial

Regional techniques are a part of multimodal analgesia following cesarean delivery. Cesarean delivery warrants a regional technique, which can provide somatic and visceral analgesia-like quadratus lumborum block (QLB) and erector spinae plane block (ESPB). In this study, we investigated the non-inferiority of ESPB at T12 and transmuscular-QLB (TQLB) at L2-L3 for postoperative analgesia in cesarean delivery. In this prospective, randomized, non-inferiority trial, 124 patients undergoing cesarean delivery were enrolled to receive bilateral TQLB or ESPB with 20 mL of 0.25% ropivacaine on each side. All patients received prophylactic acetaminophen and ketorolac for 2 days. Our primary objective was to compare the total tramadol consumption in the first 48 h between the two groups. Secondary objectives were to compare cumulative tramadol consumption, postoperative Numeric Rating Scale (NRS) score at rest, and with movement at various time points, the time for first rescue analgesic requirement, development of complications related to the block, and patient satisfaction with analgesia between the two groups. The total tramadol consumption in 48 h (47.3 ± 34.9 mg in ESPB and 50.9 ± 38.7 mg in TQLB), duration of first rescue analgesic (22.8 ± 15.8 h in ESPB and 22.7 ± 15.6 h in TQLB), and patient satisfaction were similar between the two groups. Both groups had similar pain scores except at rest at 6 h and on movement at 4 h, 6 h, and 36 h, whereas the ESPB group had lower NRS scores (P < 0.05). The analgesic effect of bilateral ESPB at T12 was non-inferior to that of bilateral TQLB post-caesarean delivery. What is already known about the topic: Cesarean delivery warrants a regional analgesia technique which can provide somatic and visceral analgesia postoperatively. While quadratus lumborum block (QLB) is a well-established technique for cesarean delivery there are very few comparative studies on erector spinae plane block (ESPB) in cesarean delivery. In the studies comparing ESPB for other lower abdominal procedures, it has been given at T9 only. What new information this study adds: The analgesic effect of bilateral ESPB at T12 was non-inferior to that of bilateral TQLB performed at L2-L3 with the same volume post-cesarean delivery and can be an important addition to multimodal analgesia protocols after cesarean delivery.