Comparative evaluation of clonidine and dexamethasone as adjuvants to ropivacaine for ultrasound-guided transversus abdominis plane block

Abstract

Aim: This study aims to study the effect of addition of clonidine and dexamethasone to ropivacaine for ultrasound-guided TAP block in patients undergoing abdominal surgeries. We primarily compared the quality and duration of postoperative analgesia. Materials and Methods: This randomized double-blind study was done after taking approval from Institutional Ethical Committee and written informed consent from all the patients. Sixty patients undergoing abdominal surgery under general anesthesia were enrolled in the study and randomly divided into two groups: Group-RC (n = 30) and Group-RD (n = 30). Patients in both the groups were given bilateral ultrasound-guided TAP block at the end of surgery. Patients in Group-RC received 20 ml ropivacaine 0.2% with 75 μg clonidine on each side and patients in Group-RD received 20 ml ropivacaine 0.2% with 4 mg dexamethasone on each side. Results: Visual analogue scale score for pain was significantly less in Group-RC as compared to Group-RD at all-time intervals (P <.05). Duration of pain relief in Group-RC was significantly greater than in Group-RD (16.50 ± 6.68 vs. 9.67 ± 6.46 h; P = 0.001). Requirement of rescue analgesia was also significantly less in Group-RC as compared to Group-RD (80% vs. 90%; P = 0.014). Except for a higher incidence of nausea in Group-RC, there was no other significant difference in the incidence of complications between the two groups. Conclusion: Addition of Clonidine (75 μg) to ropivacaine for ultrasound-guided TAP block provides better and prolonged postoperative analgesia as compared to addition of dexamethasone (4 mg) without any significant side-effects.