Blood and plasma viscometry – A comparison between three viscometers

Abstract

Plasma viscosity and the viscous component of blood viscosity were measured in an oscillatory capillary viscometer (OCR-D) and compared to the blood viscosity determined in the Contraves LS-30 machine at identical nominal shear rates and to plasma viscosity readings obtained in the Coulter Harkness capillary viscometer. The OCR-D system yields lower reproducibility compared to the other methods. It also gives lower absolute viscosity readings for blood at low shear rates. Hemoconcentration, as induced in vivo by a standard ergometer exercise, is less strongly reflected in the low shear blood viscosity data from the OCR-D system compared to the analogue results obtained in the LS-30. These findings suggest, that the OCR-D method is less reproducible and not directly comparable with the “conventional” methods. Possibly the latter are best for routine while oscillatory methods may give a more detailed analysis of specific questions.