Continuous determination of platelet aggregation during acute hemorrhage in the arterial and venous system of dogs.

Abstract

Following acute hemorrhage in dogs the kinetics of platelet aggregation were studied with a formerly described photoelectrical method. This technique allows continuous and quantitative measurements of platelet aggregates in flowing blood. Comparative investigations in the femoral artery and in the right ventricle of the heart indicated the initiation of platelet aggregation in the venous blood at an earlier phase of hemorrhage. The aggregates formed intravenously are trapped in the microvasculature of the pulmonary system. This may contribute to the delay in appearing of aggregates in the arterial blood.