HEMORHEOLOGICAL, COAGULATIVE AND FIBRINOLYTIC CHANGES DURING AUTOLOGOUS BLOOD DONATION

Background. Clinical data suggest that autologous blood donation may p revent postsurgical venous thrombosis. If confirmed, this is probably due to beneficial effects in theologic and hematologic variables which may be changed in patients as a result of repeated bleeding. Study de sign and methods. To ascertain this point, we studied variations in he matological, hemorheological, coagulative and fibrinolytic parameters in 30 patients undergoing autologous blood donation. Results. Whole bl ood viscosity (WBV), plasma viscosity and blood viscosity adjusted to 40% hematocrit, progressively and substantially decreased throughout t he successive bleeding at all the shear rates considered. WBV was furt her reduced by presurgical hemodilution with autologous plasma which d ecreased the platelet and leukocyte count. The hemostasis and fibrinol ysis variables, however, underwent no clinically significative changes . Conclusion. Repeated bleedings change most hemorheological variables . By decreasing cytocrit and viscosity, reducing aggregability and inc reasing blood cell deformability an optimal milieu to help prevent thr ombosis is artificially created.