Background and aims: SBB is the widely used excellent regional anaesthetic technique for upperlimb surgeries. Various LA agents are used for it. They have specific actions regarding time. Various novel adjuvants are used for prolonged sensory and motor blockage. We used 2 alpha agonists clonidine and dexmedetomidine for? Use of ultrasound becamepopular worldwide because we can give block to the site and dose and volume of the drug can be decreased so better blockage achieved with less adverse effects.

Material and Methods: 60 ASA grade I/II adult patients of upperlimb surgery were randomly allocated into 2 groups. 
Group C – 20 ml of 0.5% bupivacaine + 1 ug/kg clonidine
Group D –20 ml of 0.5% bupivacaine + 1 ug/kg dexmedetomidine

Results: Onset of sensory and motor blockage noted in each group . duration of sensory and motor blockage in group C 310.52±40.51, 368.22±42.58 min In group D 505.42±42.38, 560.38±32.48 min Duration of analgesia group C 340.32±38.49 min No signicant adverse reactions group D 525.38±45.36 min 

Conclusion: Addition of dexmedetomidine prolongs duration of sensory and motor blockage and duration of analgesia as compared to clonidine with 0.5% bupivacaine in SBB.