Effect of anticoagulants on blood viscosity

: In 21 cases the blood viscosity of native blood was determined in comparison to heparin blood at a shear rate of 218.7 and 1312 sec-1 by using the rotational viscosimeter Rheotest 2. As a result, a low viscosity of the heparin blood could be found. In addition, the impact of phenprocoumon treatment on several rheologic parameters was examined in 20 healthy test persons. With the haematocrit and fibrinogen level remaining constant, a reduction of blood viscosity could be observed when the Quick value decreased. This was detected with Rheotest 2 at 7 different shear rate between 218.7 and 1312 sec-1. The influence of anticoagulants on the erythrocyte deformability is discussed as a possible cause underlying the obtained decreases of viscosity. This would have to be proved by investigations using erythrocyte filters.