ABSTRACT
BACKGROUND: Induced hypotension is effective in decreasing blood loss and providing better visibility in the surgical field. Extensive epidural block to T4 with intravenous infusion of low-dose epinephrine allows mean arterial pressure to 50 mmHg. We investigated the effects of hypotensive epidural anesthesia comparing with normotensive epidural anesthesia during total hip arthroplasty. METHODS: 40 patients scheduled for total hip arthroplasty under epidural anesthesia were randomly divided into two groups. In hypotensive group, 0.5% bupivacaine 20cc was injected into L1-2 epidural space and if sensory block reached to T4, then epinephrine 1~5 g/min was intravenously injected with continuous infusion pump. As a result, mean arterial pressure was maintained 50 mmHg, and heart rate, 55~80bpm. In normotensive group, 0.5% bupivacaine 20cc was injected into L4-5 epidural space, and sensory block reached to T8. Therefore blood pressure was maintained within 20% of preoperative baseline. RESULTS: There was apparent difference in blood loss between two groups (hypotensive group: 259 +/- 75 ml, normotensive group: 803 +/- 144*ml) (*:p<0.05). In addition, in the case of hypotensive epidral group, transfusion was not required and CVP, heart rate were not changed postoperatively. Cardiac, renal, and cerebral function were preserved too. CONCLUSIONS: Hypotensive epidural anesthesia with low dose of epinephrine infusion is safely lowering mean arterial pressure to 50 mmHg. This technique is associated with low blood loss, reduction in perioperative transfusion requirements, and has no side effects on CNS, liver, kidney and heart function.