Sixty ASA grade I and II patients of either sex scheduled for elective upper limb surgery under supraclavicular brachial plexus block were divided into three equal groups in a prospective randomized double-blind controlled manner. Patients in Group C received 0.5% ropivacaine (30cc), 0.5% ropivacaine with 50 μgdexmedetomidine (30cc) in Group D and 0.5% ropivacaine (30cc) in Group D-IV along with intravenous infusion of 50μg dexmedetomidine in normal saline.

Demographic profile and surgical characteristics were similar in all the three groups. Sensory block and motor block onset was earlier in group D than in group D-IV and group C. The sensory block and motor block duration was also prolonged in group D as compared to group D-IV and group C. The duration of analgesia was significantly longer in group D and D-IV as compared to group C.

Dexmedetomidine as an adjuvant to 0.5%ropivacaine in ultrasound guided brachial plexus block shortens the sensory as well as motor onset time, prolongs sensory and motor block duration and also increases the duration of analgesia. The action of dexmedetomidine most probably is local rather than centrally mediated.