Evaluation of the yield stress of normal blood as a function of fibrinogen concentration and hematocrit.
The yield stress is a sensitive index of blood fluidity at low shear. Seven healthy adults were studied at hematocrits varying between 40 and 80% and fibrinogen concentrations from 0.0 to 0.935 g/dl. Multivariable analysis was used to determine the functional dependence of yield stress on hematocrit and fibrinogen level. The major findings from this analysis include a decreasing effect of fibrinogen at high concentrations (saturation effect), a relative insensitivity of yield stress to fibrinogen at low concentration (threshold effect), and a strong interaction between the effects of hematocrit and fibrinogen concentration on yield stress. Our results give the normal range of yield stress for a given value of fibrinogen and hematocrit and can be used to predict the effect of reductions in hematocrit or fibrinogen on the yield stress of normal blood.
Morris
C L
CL
Department of Hematology/Oncology, Children's Hospital Medical Center, Cincinnati, Ohio 45229-2899.
Rucknagel
D L
DL
Shukla
R
R
Gruppo
R A
RA
Smith
C M
CM
Blackshear
P
P
D000328:Adult; D001783:Blood Flow Velocity; D001809:Blood Viscosity; D005340:Fibrinogen / Q000378:metabolism*; D006400:Hematocrit; D006801:Humans; D066298:In Vitro Techniques
D005340:Fibrinogen