Group BF ( n = 62 ) received intrathecal fentanyl 25 microg plus 3 ml of 0.5 % hyperbaric bupivacaine , Group BS ( n = 62 ) received 0.5 ml normal saline plus 3 ml of 0.5 % hyperbaric bupivacaine and Group BT ( n = 62 ) received intrathecal tramadol 25 mg plus 3 ml of 0.5 % hyperbaric bupivacaine .