Hemorheological investigation of clotting by rotational viscometer

Abstract

HAAKE Rotovisco RV100/CV100 was employed to investigate coagulation of whole blood, platelet rich plasma (PRP) and plasma. Samples were anticoagulated with sodium citrate. Clotting was initiated by adding CaCl₂ Shear stress versus time at shear rate 0.3 s⁻¹ at 37°C was recorded. Two parameters were established: (1) Recalcification time t_r; and (2) viscosity increasing rate dη/dt. The parameters appeared to be meaningful to the clotting behaviour of blood, PRP and plasma. Several antithrombotics were tested by the method. Warfarin prolonged t_r with a dramatic suppression of dη/dt (P<0.001). Aspirin decreased dη/dt (P<0.001) without significant influence on t_r. Heparin showed dose-response correlations for both the parameters. The unconventional test of clotting by rotational viscometer may have its potential in clinical practice of hemorheology.