METHODS	Thirty volunteers received 5 injections each : ( 1 ) needle only , ( 2 ) bupivacaine 0.5 % , ( 3 ) ropivacaine 0.5 % , ( 4 ) bupivacaine 0.5 % with dexamethasone 0.13 mg/mL , and ( 5 ) ropivacaine 0.5 % with dexamethasone 0.13 mg/mL .\