Peri-neural Dexmedetomidine Versus Dexamethasone for Supraaclavicular Block Adjuvant to Bupivacaine Supraclavicular Brachial Plexus Block

perineural injection of Bupivacaine 30 ml 0.25% combined with 50 microgram (0.5 ml) peri-neural dexmedetomidine plus 1.5 ml normal saline

perineural injection of Bupivacaine 30 ml 0.25% combined with 4 mg peri neural dexamethasone (2 ml)

perineural injection of Bupivacaine 30 ml 0.25% combined with 2 ml normal saline