Integral viscosity: a useful parameter in evaluating whole blood and plasma viscosities in health and disease.

An integral viscosity determination (Q) is proposed for whole blood (QB) and plasma (Qp). The integral viscosity determination was carried out at four shear rates in a Brookfield LTV Viscometer and calculation were obtained by means of a modification of Casson's mathematical model. Polycythemic and paraproteinemic patients resulted to be well differentiated from normals. The ratio QB/Qp represent a continuous sum of relative viscosities and may also supply information on erythrocytes deformability. Integral viscosity determinations are indicated for research purposes and for examining special cases.