Perineural versus intravenous clonidine as an adjuvant to Bupivacaine in supraclavicular Brachial plexus block

Addition of clonidine 2mcg/kg to 28 ml of 0.5% bupivacaine in brachial plexus blocks results in a faster onset, increased duration of block and longer postoperative pain relief when compared to bupivacaine alone. These advantages are not observed when the same dose of clonidine is injected intravenously.