Background: We compared the effects of adding dexmedetomidine and clonidine to a 35 ml solution of 0.375% bupivacaine in supraclavicular brachial plexus block. Onset and duration of sensory and motor block along with the duration of analgesia were the primary endpoints.

Materials and Methods: sixty patients posted for upper limb surgeries were enrolled for a prospective, randomized, double-blind, study. Patients were divided into two groups, the group BC and the group BD. In group BC (n = 30), 35 ml of 0.375% bupivacaine + 1mcg/kg clonidine; and in group BD (n = 30), 35 ml of 0.375% bupivacaine + 1 mcg/kg dexmedetomidine were given for supraclavicular brachial plexus block using the peripheral nerve stimulator. Onset and duration of sensory and motor blocks were assessed along with the duration of analgesia, sedation, and adverse effects, if any. Hemodynamic parameters, like heart rate (HR), systolic arterial blood pressure (SBP), and diastolic arterial blood pressure (DBP) were also monitored.

Results: Demographic data and surgical characteristics were comparable in both the groups. The onset times for sensory and motor blocks were significantly shorter in BD than BC group (P < 0.001), while the duration of blocks was significantly longer (P < 0.001) in BD group. The duration of analgesia (DOA) was significantly longer in BD group than BC group (P < 0.001). No other adverse effects were observed in either of the groups.

Conclusion: Dexmedetomidine added as an adjuvant to bupivacaine for supraclavicular brachial plexus block significantly shortens the onset time and prolongs the duration of sensory and motor blocks and duration of analgesia. Patients in group BD were adequately sedated (modified Ramsay Sedation Score) with no adverse effects.