DIFFERENCES IN PERIPHERAL ARTERIAL AND VENOUS HEMORHEOLOGIC PARAMETERS

To evaluate the comparability of hemorheologic parameters in arterial and venous blood, we measured hematocrit, whole blood viscosity, plasm a viscosity, erythrocyte deformability, erythrocyte aggregation, and e rythrocyte indices in both arterial and venous blood from 20 consecuti ve patients scheduled for coronary artery surgery and/or valve replace ment surgery. Hematocrit, whole blood viscosity at three shear rates ( 0.05 s(-1), 0.5 s(-1), and 70 s(-1)), plasma viscosity, and erythrocyt e aggregation factor were statistically significantly higher in venous blood than in arterial blood, The differences may be explained by the difference in hematocrit. Erythrocyte deformability did not differ si gnificantly. With the availability of more precise rheological measure ment techniques, differences such as those encountered in this study m ay be of importance in clinical studies. It is concluded that arterial and venous blood samples are not entirely theologically comparable.