To compare the onset and duration of sensory and motor block ,perioperative analgesia , side effect profile of both drugs and to evaluate the better adjuvant to spinal anaesthesia between Dexmedetomidine and Buprenorphine.

Sixty patients of ASA I and II undergoing lower abdominal surgeries were randomly allocated into two groups (group A and group B ) and received the following drugs. Group A—15 mg of 0.5%hyperbaric bupivacaine + 10µg of Dexmedetomidne. Group B—15 mg of 0.5%hyperbaric bupivacaine + 60µg of Buprenorphine. Sensory and motor blockade characteristics of both groups ( onset, maximum blocks, time for maximum blocks, 2 segment regression, regression of motor block to modified bromage 0, regression of sensory block to

Addition of dexmedetomidine as adjuvant to bupivacaine had significantly shortened the onset of sensory blockade, prolonged the duration of sensory and motor block and had postponed the time for first analgesic request. Side effects like shivering, nausea, vomiting, pruritus, were more in patients receiving buprenorphine. Intraoperative hypotension and bradycardia were present in both the groups but more evident in dexmedetomidine group.

10 µg of dexmedetomidine seems to be a better alternative to