Total exchange transfusion in rats with hemoglobin solutions: influence of hemoglobin concentration

In most published studies of the oxygen transport capacity of hemoglobin solutions for total or partial replacement transfusions, the hemoglobin concentrations have been in the order of 70 g/l. In this study we tried to identify the hemoglobin concentration that would give the best survival in rats at zero hematocrit. The longest survival time, of more than 4 h, was obtained with a hemoglobin concentration of 125 g/l, despite an oncotic pressure much higher than that of plasma. This observation suggests the use of more highly concentrated solutions of modified or unmodified hemoglobin than are presently recommended, in order to increase their oxygen transport capacity.