Comparison of ultrasound-guided quadratus lumborum block-2 and quadratus lumborum block-3 for postoperative pain in cesarean section: A randomized clinical trial

The aim of this study was to compare the postoperative analgesic effects of ultrasound-guided quadratus lumborum block-2 (QLB-2) and quadratus lumborum block-3 (QLB-3) after cesarean section (C/S) under general anesthesia. METHOD: This was a prospective, randomized, double-blind study. A total of 143 term pregnant women with American Society of Anesthesiologists II status, who were scheduled for elective C/S under general anesthesia were randomly separated into QLB-2 and QLB-3 groups. After surgery under standardized general anesthesia, QLBs were performed with 0.3 mL.Kg(-1) 0.25% bupivacaine in both groups. Patient-controlled analgesia (PCA) devices were used for additional analgesia. The primary outcomes were pain scores evaluated at 0, 2, 6, 12, and 24 hours. In addition, PCA demands, actual delivered tramadol doses, rescue analgesic requirements, anesthesia time, and patient satisfaction were recorded. RESULTS: A total of 104 patients were analyzed statistically. Pain scores were statistically lower in the QLB-3 group at 2, 6, 12, and 24 hours postoperatively (P = .001). Anesthesia time was longer in the QLB-3 group. Patients who received QLB-3 block demonstrated significantly fewer PCA demands and lower consumption of tramadol (P = .003). Moreover, the first analgesic requirement time was longer along with higher patient satisfaction. In addition, all procedures were performed without any complications and side effects due to PCA were negligible. CONCLUSIONS: This study demonstrated that, although both QLBs were safe and reliable, QLB-3 provides more effective analgesia and patient satisfaction than QLB-2 in C/S.