Restitution of blood volume after hemorrhage: mathematical description

An analytical model was developed to simulate the restitution of blood volume after hemorrhage. This model was used to test two previously proposed hypotheses for the restoration of plasma oncotic pressure required for full restitution of blood volume: increased lymphatic flow or decreased trans-capillary leakage of albumin. Neither hypothesis could account for the temporal and quantitative features of experimentally observed restitution of blood volume. An alternate hypothesis, that restitution of blood volume results from a fluid shift from intracellular-extracellular fluid shift occurs in dogs treated with high doses of cortisol analog. Thus the results of the simulation support the hypothesis that full restitution of blood volume requires an intracellular-extracellular fluid shift. This fluid shift may be mediated by high circulating levels of cortisol secondary to hemorrhage.