Nonlinear Effects Observed During Erythrocyte Sedimentation in Blood Diluted by Its Own Plasma. Blood as Active Colloid System

The dynamics of sedimentation of blood erythrocytes was studied during its sequential dilution with its own plasma in vitro. It was shown that with an increase in the degree of dilution of whole blood over 5%, a monotonous increase in the average erythrocyte sedimentation rate is observed. Dynamic changes in the density of the plasma-red cells border were found, which are manifested in the oscillatory nature of changes in the rate of the process and the phenomena of “negative sedimentation rate.” They are associated with structural reorganization of the system and phase separation “associated plasma/erythrocytes,” and can be modulated by the relative content of plasma in the blood, exhibiting a non-monotonic nature of the changes. The results obtained can be useful for further development of a model of behavior of blood cells as an active colloid, as well as for the creation of a method for monitoring the individual dosage of infusion solutions used in clinical practice for blood loss, for detoxification, treatment and prevention of thrombophlebitis and shock conditions.