Quadratus lumborum block vs. transversus abdominis plane block in laparoscopic trans-abdominal pre-peritoneal repair of inguinal hernia in adults: A randomised controlled trial

Background and Aims: Laparoscopic trans abdominal preperitoneal (TAPP) repair of hernia is one of the most commonly performed surgeries and may cause significant postoperative pain. Among different truncal block techniques, quadratus lumborum (QL) and transversus abdominis plane blocks (TAP) are used during this abdominal surgery. We aimed to investigate whether, bilateral QL block by trans-muscular approach provided better analgesia as compared to posterior TAP block in these patients. Methods: Forty adult patients with American Society of Anesthesiologists physical status I and II, undergoing inguinal hernia repair were randomized to receive either QL or TAP block, with 20 mL of 0.25% ropivacaine bilaterally. The primary objective of the study was to compare the total fentanyl consumption (in μg) within 24 hours postoperatively. The secondary objectives studied were dermatomal spread, quality of recovery at discharge and at 3 months postoperatively. Results: There was a significant reduction in total 24-hour fentanyl consumption (552 ± 229.56 vs 735.5 ± 264 μg, P =0.01) in the QL group, with longer duration of analgesia [282.5 ± 89.9 min group TAP vs. 354.8 ± 107 min QL, (mean difference -72.34,95% confidence interval -135.516 to -9.024), P =0.03], as compared to TAP group. At T8 and T9 dermatomes, greater proportion of patients in the QL group attained analgesia. Quality of Recovery at 24 hours and at 3 months of follow-up were comparable. Conclusion: QL block provided better perioperative analgesia than TAP block, in patients undergoing laparoscopic hernia repair. It also leads to greater dermatomal spread but without any decrease in the incidence of chronic pain at 3 months postoperatively.