Normovolemic hemodilution and lumbar epidural anesthesia

This randomized study was designed to determine the cardiovascular effects of normovolemic hemodilution and lumbar epidural anesthesia in patients scheduled for vascular surgery. The patients were randomly assigned to three different groups: group 1 (N = 10) included patients undergoing lumbar epidural anesthesia without hemodilution; group 2 (N = 10) consisted of patients with normovolemic hemodilution without epidural anesthesia; and in group 3 (N = 10) normovolemic hemodilution was produced during lumbar epidural anesthesia. The three groups included several patients with a history of either myocardial infarction or stable mild angina or treated and controlled hypertension. In group 1, the level of epidural anesthesia reached T-9 +/- 1. After lumbar epidural anesthesia and 7 mL/kg colloid infusion, pulmonary capillary wedge pressure increased slightly but significantly above baseline, without significant changes either in mean arterial pressure or in cardiac index. In group 2, the same colloid infusion as in group 1 when infused before normovolemic hemodilution increased pulmonary capillary wedge pressure and cardiac index without significant effects on arterial blood pressure. Normovolemic hemodilution using a colloid solution decreased hemoglobin concentration (18%) and increased cardiac index significantly (9%). No significant change in systemic oxygen transport or in total body oxygen consumption was observed. In group 3, with anesthesia to T-9 +/- 1, hemodynamic changes were as observed in group 1. After normovolemic hemodilution, hemoglobin concentration decreased significantly (15%), whereas cardiac index increased significantly (15%) without significant changes either in mean arterial pressure or in heart rate. Systemic oxygen transport and total body oxygen consumption did not change significantly. No patient experienced chest pain or electrocardiographic evidence of myocardial ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)