[Role of carbon dioxide in the correction of coagulation hemostasis during hypoxia]

In acute animal experiments coagulation hemostasis reactions and blood acid-base state were investigated when dogs were breathing hypoxic (10% O2) or hypoxic-hypercapnic (10% O2, 5% CO2) gas mixtures. When given the hypoxic mixture, activation of blood coagulation was accompanied by depression of anti-coagulatory and fibrinolytic properties. These changes developed together with distinct hypoxemia, respiratory alkalosis and secondary metabolic acidosis. When given the hypoxic-hypercapnic mixture, no hypercoagulation occurred which can be explained by higher (than on the hypoxic mixture) paO2, lack of disorders in acid-base equilibrium and in oxygen supply. It is believed that the ability of carbon dioxide to maintain relative normocoagulation when added to the hypoxic mixture is one of the factors that increase tolerance to hypoxia.