A comparitive study of clonidine and dexmedetomidine as adjuvant to 0.25% bupivacaine in supraclavicular brachial plexus block for post operative analgesia and sedation

Background: Alpha -2 agonists are used in subarachnoid, epidural, regional blocks for their onset, duration and postoperative analgesia.(1-3)We compared the effects of adding clonidine and dexmedetomidine, as both are alpha -2 agonist, to a 35 ml solution of 0.25% bupivacaine in supraclavicular brachial plexus block. Materials and Methods: Eighty patients of ASA 1 and 2 posted for upper limb orthopaedic surgeries were enrolled for a prospective, randomized, double-blind trial. Patients were divided into two groups, the Clonidine group C and the Dexmedetomidine group D. In group C (n = 40), 0.25% Bupivacaine + 1 μg/kg Clonidine; and in group D (n = 40), 0.25% Bupivacaine + 1μg/kg Dexmedetomidine, with the total volume of drug solution 35 cc. Drug solution were given for supraclavicular brachial plexus block using the peripheral nerve stimulator. The effects of adjuvants on duration of analgesia and sedation were compared. Results: Demographic data and surgical characteristics were comparable in both the groups. Postoperative analgesia (POA) was longer in group D 637.50 ± 30.19 minutes than group C 294.38 ± 29.74, while Ramsay sedation score was higher in group D than group C. Conclusion: Dexmedetomidine significantly prolonged the duration of postoperative analgesia along with high sedation scores.