Comparative Study between Bupivacaine versus Bupivacaine with Dexmeditomidine in Ultrasound Guided Transversus Abdominis Plane Block for Postoperative Analgesia in Cancer Patients Undergoing Major Pelviabdominal Surgeries

Abstract Background: The main contributor to the pain experienced after abdominal surgery is pain from the incision made in the abdominal wall. The Transversus Abdominis Plane (TAP) block is a peripheral nerve block to the nerves supplying the anterior abdominal wall (T6 to L1). The aim of this study was to evaluate the effect of dexmedetomidine as an adjuvant in ultrasound guided TAP block on post-operative analgesia and morphine consumption in patients undergoing major abdominal or pelvic surgeries.
Methods: Seventy five patients were randomly enrolled in the study; patients were divided into 3 groups: Bupivacaine group (group TAP, n=25) received TAP block with bupivacaine done after skin closure, bupivacaine with dexmedetomidine group (group TAP + Dex, n=25) received TAP block with dexmedetomidine added to the bupivacaine and intravenous dexmedetomidine group (group TAP + IV-Dex) received TAP block with bupivacaine in addition to intravenous dexmedeto-midine. Results: The mean time to the first rescue analgesic requirement was significantly longer in both group TAP + Dex (9.8±2.9) hours and group TAP + IV-Dex (10.0±2.3) hours than in group TAP (5.7±1.6) hours (p<0.001). Total morphine consumption in the first 24 hours post-operatively was significantly higher in group TAP (24.3±3.6) mg than in both group TAP + Dex (11 .8±3.7) mg and group TAP + IV-Dex (11.8±3.6) mg (p<0.001). Post-operative VAS pain score was higher in group TAP than in group TAP + IV-Dex at 6 and 12 hours but all three groups were comparable at 2, 4 and 24 hours. Patient satisfaction score was significantly lower for group TAP in comparison to the other two groups (p< 0.001).
Conclusion: Dexmedetomidine whether added to bupi-vacaine in the TAP block or administered intravenously improved postoperative analgesia with lower total morphine consumption in the first 24 hours post-operative as a part of multimodal analgesia in abdominal and pelvic surgeries.