HEMODILUTION AND INTRAVENOUS PERFLUBRON EMULSION AS AN ALTERNATIVE TOBLOOD-TRANSFUSION - EFFECTS ON TISSUE OXYGENATION DURING PROFOUND HEMODILUTION IN ANESTHETIZED DOGS

BACKGROUND: Intravenously administered perfluorocarbon (PFC) emulsions increase oxygen solubility in plasma. PFC might therefore temporarily replace red cells (RBCs) lost during intraoperative hemorrhage. In pa tients who have undergone hemodilution, the return of autologous blood may be delayed by the administration of PFC, and autologous RBCs may be saved for transfusion after surgical bleeding is stopped and PFC is cleared by the reticuloendothelial system. STUDY DESIGN AND METHODS: In 22 anesthetized, hemodiluted dogs (hemoglobin [Hb] 7 g/dL) breathin g 100-percent O-2, an intraoperative volume-compensated blood loss was simulated. The efficacy of three therapeutic regimens in maintaining tissue oxygenation was compared: 1) RBC group (n = 7): maintenance of a Hb >7 g per dL by transfusion of autologous RBCs; 2) PFC group (n = 7): bolus application of a second-generation PFC emulsion (60% wt/vol perflubron) and further acute normovolemic hemodilution (ANH) to a Hb of 3 g per dL; and 3) control group (n = 7): further ANH alone to a Hb of 3 g per dL. Systemic and myocardial oxygenation status and tissue oxygenation were assessed. RESULTS: Autologous RBCs transfused to main tain a Hb of 7 g per dL preserved hemodynamics and tissue oxygenation during blood loss. in the PFC and control groups, heart rate and cardi ac index increased significantly in response to further ANH. Tissue ox ygenation was not different in the PFC and the RBC groups. Direct comp arison of the PFC and control groups revealed better tissue oxygenatio n in the PFC group, as reflected by significantly higher mixed venous, coronary venous, and local tissue pO(2) on liver and skeletal muscle. CONCLUSION: Bolus intravenous administration of 60-percent (wt/vol) p erflubron emulsion and further hemodilution from a Hb of 7 g per dL to one of 3 g per dL were as effective as autologous RBC transfusion in maintaining tissue oxygenation during volume-compensated blood loss de signed to mimic surgical bleeding.