A comparative evaluation of different doses of dexmedetomidine as an adjuvant to bupivacaine in transversus abdominis plane block for postoperative analgesia in unilateral inguinal hernioplasty

BACKGROUND AND AIMS: The present study is designed to evaluate addition of two different doses of dexmedetomidine (0.25 mcg/kg and 0.5 mcg/kg) as an adjuvant to bupivacaine in transversus abdominis plane block for post-operative analgesia in patients undergoing unilateral inguinal hernioplasty. MATERIAL AND METHODS: A total of 90 patients scheduled to undergo elective unilateral open inguinal hernioplasty were divided into three groups in a randomized triple blind way. In group B (n = 30), patients received TAP block using 22 ml of solution, consisting of 20 ml of 0.25% bupivacaine and 2 ml of normal saline; in group BD1 (n = 30), patients received TAP block using 22 ml of solution, consisting of 20 ml of 0.25% bupivacaine and dexmedetomidine 0.25 mcg/kg dissolved in 2 ml of normal saline; while in group BD2 (n = 30), patients received TAP block using 22 ml of solution, consisting of 20 ml of 0.25% bupivacaine and dexmedetomidine 0.5 mcg/kg dissolved in 2 ml of normal saline. RESULTS: Time to first analgesia was significantly prolonged in group BD2 (874.48 ± 118.28 minutes) as compared to BD1 (536.5 ± 60.35 minutes) and B (341.5 ± 46.22 minutes) (P < 0.0001). Total consumption of diclofenac was also reduced in BD2 (80.17 ± 19.34 mg) as compared with B (150 ± 0 mg) and BD1 (147.5 ± 13.69 mg) (P < 0.001). Patients in dexmedetomidine group were more sedated at 1-hour (P < 0.05). None of our patients required any intervention for hemodynamic changes which were significantly more in dexmedetomidine group. CONCLUSION: Dexmedetomidine in a dose of 0.5 mcg/kg is better than dose of 0.25 mcg/kg as an adjuvant to 0.25% bupivacaine in transversus abdominis plane block for post-operative pain relief in unilateral inguinal hernioplasty. However, it causes mores sedation and hemodynamic changes.