HEMOSTATIC AND FIBRINOLYTIC RESPONSE TO DESMOPRESSIN IN UREMIC PATIENTS

Desmopressin (DDAVP) 0.3 mu g/kg was infused in 20 uremic patients wit h prolonged bleeding time, Prior to infusion, the uremic patients had a reduced revel of tissue plasminogen activator (t-PA), normal levels of von Willebrand factor antigen (vWF:Ag) and ristocetin cofactor acti vity (vWF:RCo) and elevated level of factor VIII coagulant activity (F VIII:C). Patients with lower hematocrit or t-PA levels tended to have a longer bleeding time, One hour after DDAVP infusion, the bleeding ti me was shortened significantly, This improvement was significant in al l patient groups irrespective of the high or low initial levels of fac tor VIII complex components, Plasma levels of FVIII:C, vWF:Ag, vWF:RCo and t-PA all increased significantly. The magnitude of increase in th ese factors, however, was not significantly correlated with the extent of bleeding time shortening. The multiple regression model for predic ting the extent of bleeding time shortening suggested only two variabl es, viz initial bleeding time and posttreatment F-VIII:C activity to b e of significance. The present results indicate that the hemostatic re sponse to DDAVP is uniform in uremic patients, regardless of whether t he initial activities of factor VIII complex components are high or lo w. Posttreatment FVIII:C activity appears to play a significant role i n the hemostatic action of DDAVP. Furthermore, a depressed fibrinolyti c activity was generally observed to concur with the hemostatic defect in uremic patients.