Viscoelastic coagulation studies of whole blood and plasma using a modified thrombelastograph

Abstract

The viscoelastic behavior of coagulating plasma and whole blood were examined in a modified thrombelastograph. We found that platelets greatly increased the measured rigidity of coagulating blood and plasma, and this rigidity was augmented by erythrocytes. Red cells also slowed the rate of stiffening, which may be due to the red cell membrane activity. In whole blood, the relaxation of stress at constant strain demonstrated a biphasic pattern: the early rapid phase depended on the primary orientation of fibrin into a network by platelets and red cells. The second slower phase was dependent on Factor XIII activity in secondary rearrangement of the network. Crosslinking of fibrin by Factor XIII had little effect on rigidity.