Comparative Efficacy of Ultrasound-Guided TAP Block Vs. Quadratus Lumborum Block for Postoperative Analgesia in Abdominal Surgery

Abstract

Ultrasound-guided transversus abdominis plane (TAP) block and quadratus lumborum (QL) block are commonly used regional anesthesia techniques for postoperative analgesia in abdominal surgery. Comparative evidence regarding their analgesic effectiveness in routine clinical practice remains limited. This study aimed to compare postoperative analgesic outcomes between patients receiving TAP block and those receiving QL block.This comparative cross-sectional study was conducted on 120 adult patients who underwent elective abdominal surgery and received either ultrasound-guided TAP block (n=60) or QL block (n=60) as part of multimodal analgesia. Demographic and perioperative data were recorded. Primary outcome was total opioid consumption within 24 hours postoperatively. Secondary outcomes included visual analogue scale (VAS) pain scores at 1, 2, 6, 12, and 24 hours, time to first rescue analgesia, and incidence of postoperative nausea and vomiting (PONV). Continuous variables were compared using independent t-test, and categorical variables were analyzed using chi-square test. Time-to-event analysis was performed using Cox regression. Baseline demographic and surgical characteristics were comparable between groups (p > 0.05). Patients receiving QL block demonstrated significantly lower postoperative VAS scores at all measured time points (p < 0.01). Mean 24-hour opioid consumption was significantly reduced in the QL group compared with the TAP group (12.3 ± 5.9 mg vs 18.6 ± 6.8 mg; p < 0.001). The mean time to first rescue analgesia was significantly longer in the QL group (10.4 ± 3.1 hours vs 6.2 ± 2.4 hours; p < 0.001). Cox regression analysis showed that QL block was associated with a significantly lower hazard of requiring rescue analgesia (adjusted HR 0.48, 95% CI 0.30–0.76; p = 0.002). Incidence of PONV was lower in the QL group but was not statistically significant (15.0% vs 26.7%; p = 0.11). In this comparative cross-sectional analysis, ultrasound-guided QL block was associated with superior postoperative analgesia compared to TAP block, reflected by lower pain scores, reduced opioid consumption, and prolonged time to rescue analgesia. QL block may provide enhanced postoperative pain control in abdominal surgery.

Keywords-Quadratus lumborum block; Transversus abdominis plane block; Comparative study; Postoperative analgesia; Opioid consumption; Abdominal surgery.