Patient-controlled Analgesia Using Ropivacaine (0.25%) Through Transversus Abdominis Plane vs. Epidural Route for Postoperative Pain Relief Following Midline Laparotomy: A Single Center Open-label Randomized Control Trial (Wireless Trial).

Introduction: The WIRELESS trial compared the postoperative analgesic effect of the bilateral transversus abdominis plane patient-controlled analgesia (TAP-PCA) with that of epidural patient-controlled analgesia (E-PCA) using ropivacaine 0.25%.

Methodology: A hundred patients aged between 18 and 85 years and planned for upper midline laparotomy (Class I and II wounds) under general anesthesia were randomized into TAP-PCA (50) and E-PCA (50) groups. The PCA pump used for the study was designed to deliver a baseline infusion rate of 5 mL/hour (0.25%). The patients were instructed to press the PCA button, as and when required to deliver an additional dose of 2 mL, with 15-minutes lockout period. Both groups received 1 g of paracetamol infusion every 8 hours. The pain score was evaluated at 3, 6, 12, and 24 hours and then every 12 hours till 72 hours postoperatively. The requirements of rescue analgesia (injection tramadol), out-of-bed mobilization, and recovery of bowel function were recorded. Drug-related side effects and catheter-related complications were also noted.

Results: Five (10%) patients in the TAP arm and 17 (34%) patients in the epidural arm could not complete the study due to complications/failure. The intention-to-treat analysis indicates that VAS scores were similar in both groups (47 in the epidural PCA group and 48 in the TAP-PCA group) at 3, 12, 24, 36, 48, 60, and 72 hours. Rescue analgesia (tramadol) was similar in both groups (0.21, 0.58 vs. 0.13, 0.44). There were no significant differences observed between the 2 groups in terms of out-of-bed mobilization and pulmonary complications. Nonetheless, the TAP arm showed the earlier passage of the first flatus and a shorter hospital stay compared with the epidural arm.

Conclusion: PCA through the TAP route is not inferior to the epidural route for managing postoperative pain. Because of fewer contraindications and complications, TAP-PCA can be considered an alternative to epidural PCA.