Transversus abdominis plane block with liposomal bupivacaine versus continuous epidural analgesia for major abdominal surgery: The EXPLANE randomized trial

Objective: Compare transversus abdominis plane (TAP) blocks with liposomal bupivacaine were to epidural analgesia for pain at rest and opioid consumption in patients recovering from abdominal surgery. Background: ERAS pathways suggest TAP blocks in preference to epidural analgesia for abdominal surgery. However, the relative efficacies of TAP blocks and epidural analgesia remains unknown. Methods: Patients having major abdominal surgery were enrolled at six sites and randomly assigned 1:1 to thoracic epidural analgesia or bilateral/4-quadrant TAP blocks with liposomal bupivacaine. Intravenous opioids were used as needed. Non-inferiority margins were a priori set at 1 point on an 11-point pain numeric rating scale for pain at rest and at a 25% increase in postoperative opioid consumption. Results: Enrollment was stopped per protocol at 3rd interim analysis after crossing an a priori futility boundary. 498 patients were analyzed (255 had TAP blocks and 243 had epidurals). Pain scores at rest in patients assigned to TAP blocks were significantly non-inferior to those given epidurals, with an estimated difference of 0.09 points (CI: −0.12, 0.30; noninferiority P < 0.001). Opioid consumption during the initial 3 postoperative days in TAP patients was not non-inferior to epidurals, with an estimated ratio of geometric means of 1.37 (CI: 1.05, 1.79; non-inferiority P = 0.754). However, the absolute difference was only 21 mg morphine equivalents over the 3 days. Patients with epidurals were more likely to experience mean arterial pressures <65 mmHg than those given TAP blocks: 48% versus 31%, P = 0.006. Conclusion: Pain scores at rest during the initial three days after major abdominal surgery were similar. Patients assigned to TAP blocks required more opioid then epidural patients but had less hypotension. Clinicians should reconsider epidural analgesia in patients at risk from hypotension. Trial Registration: ClinicalTrials.gov Identifier: NCT02996227.