Quadratus Lumborum Block versus Transversus Abdominis Plane Block for Postoperative Analgesia in Inguinal Hernia Surgery: A Comparative Study

Background: Postoperative pain following inguinal hernia surgery can affect early recovery and patient satisfaction. Ultrasound-guided quadratus lumborum (QL) block may provide broader and more prolonged analgesia than transversus abdominis plane (TAP) block. This study compared the postoperative analgesic efficacy of lateral QL block and TAP block in patients undergoing inguinal hernia surgery. Methods: This prospective, randomized, parallel-group, investigator-blinded study included 100 adult patients (ASA I–II) aged 25–60 years undergoing inguinal hernia repair under spinal anaesthesia. Patients were randomly allocated to receive either unilateral QL block or unilateral lateral TAP block, with 20 mL of 0.25% bupivacaine administered on each side. Postoperative pain was assessed using the Visual Analogue Scale (VAS) at predefined intervals for 24 hours. Duration of sensory blockade, time to first analgesic request, rescue analgesic requirement, patient satisfaction, haemodynamic parameters, and postoperative complications were also recorded. Results: Baseline demographic and clinical characteristics were comparable between the groups. The duration of sensory blockade was significantly longer in the QL group than in the TAP group (10.94 ± 0.74 vs 6.26 ± 1.24 hours; p < 0.001). The time to first analgesic request was also significantly longer with QL block (7.42 ± 0.61 vs 4.21 ± 0.60 hours; p < 0.001). The QL group required significantly fewer rescue analgesics (0.74 ± 0.75 vs 1.98 ± 0.86; p < 0.0001). From 6 hours onward, postoperative VAS scores were significantly lower in the QL group, with particularly marked differences at 8, 12, and 24 hours (p < 0.001). Patient satisfaction was higher in the QL group (98% vs 68%; p < 0.001). Postoperative complications were also less frequent in the QL group (4% vs 48%; p < 0.001). Haemodynamic parameters remained relatively stable in both groups. Conclusion: Lateral QL block provided more prolonged postoperative analgesia than posterior TAP block in patients undergoing inguinal hernia surgery, with delayed rescue analgesic requirement, reduced analgesic consumption, lower late postoperative pain scores, and greater patient satisfaction.