Changes in blood filterability in cerebrovascular accidents.

Patients with acute cerebrovascular accidents (CVA) exhibit pathological changes of various hemorheological factors in dependence of severity of the clinical condition. Increase in hematocrit, rise in blood viscosity and impairment of red cell deformability together with increase in plasma proteins, especially of fibrinogen and inflammatory proteins, leukocytosis, hemoconcentration and presence of various risk factors affect cerebral blood flow on microcirculatory level and produce a prethrombotic situation. Deteriorated blood filterability may be regarded as an indicator of severity and prognosis of CVA. Studies of red cell filterability in 100 patients with severe recent CVA and 52 patients with moderate CVA showed in comparison to matching controls a progressing deterioration of filtration up to day 8 whereafter an improvement started in recovering patients. Febrile patients presented clearly more filterability deterioration than non-febrile subjects. Hyperviscosity states seem to respond best to normovolemic hemodilution, whereas red cell deformability and aggregation can be approached by various drugs such as pentoxifylline, piracetam etc. Follow up of blood filtration in CVA patients is of significant prognostic value.