The differences in the cardiopulmonary effects of blood transfusion and dextran infusion in acute hemorrhagic hypotension were studied in 23 mongrel dogs. In this study, the dogs were divided into two groups, namely the transfusion group and the dextran infusion group. In both groups, the dogs were rapidly bled from the femoral artery until the femoral arterial mean pressure was reached to about 40 mm. Hg at this level for 50 minutes, followed by the re-transfusion of blood in the transfusion group and the infusion of 6% dextran to the amount of blood withdrawn in the dextran infusion group. In both groups, hemodynamics and pulmonary functions were measured before and after. transfusions and infusions, respectively, at 30 minute intervals for 120 minutes and at the end of 180 minutes.
No significant differences were noted in the femoral arterial mean pressure, the heart rate and the pulmonary functions between two groups. On the contrary the increase in the stroke volume, the cardiac index and the femoral venous pressure, and the decrease in the total peripheral resistance and the arteriovenous oxygen difference following blood transfusion or dextran infusion were more marked in the dextran infusion group. It was felt that these differences beween these two groups were attributable to the increase in the fluid volume caused by the high osmotic pressure of the dextran and the decrease in the viscosity of the blood with the resultant improvement of the microcirculation.
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