Supraclavicular Brachial Plexus Block During Upper Limb Surgeries

20 ml volume bupivacaine only (0.5%concentration) (with maximum dose not exceeding 4mg/kg ) plus ketamine (1 mg/kg) with maximum dose 100mg ; the total volume is 30 ml with the infusion of 100 ml normal saline at a rate of 100ml/h.

20 ml volume bupivacaine only (0.5%concentration) (with maximum dose not exceeding 4mg/kg ) plus 10 ml saline ; the total volume is 30 ml with the infusion of ketamine 0.15 mg/kg added to 100 ml normal saline and will be infused at a rate of 100 ml/h, which will be stopped 5 min before the end of surgery.