Hematologic studies during isolated ultrafiltration

: The effect of negative-pressure isolated ultrafiltration on leucocytes, platelets, and clotting factors was evaluated in maintenance hemodialysis patients. A significant decrease in the number of leucocytes was observed during the first 45 minutes of ultrafiltration. However, by one hour, leucocyte counts had returned to pre-ultrafiltration values. A slight, of haptoglobin, free hemoglobin, or fibrinogen after one hour of isolated ultrafiltration. Levels of fibrin degradation products and fibrin monomers similarly showed no change. Heparin administration alone had no effect on the above hematologic values. We suggest that isolated ultrafiltration, as clinically practised, has little acute effect on the coagulation system, and does not cause detectable hemolysis. The transient decrease in leucocyte count, and the modest fall in platelet count that were found are in keeping with changes previously reported to occur during hemodialysis.