[Shortening of acetylsalicylic acid-prolonged bleeding time by means of desmopressin].

The pathomechanism of desmopressin (DDAVP)-dependent shortening of the bleeding time prolonged by acetylsalicylic acid (ASA) was investigated by the Ivy bleeding time (BT) and the in vitro bleeding test (IVBT). Additionally, platelet aggregation and von Willebrand factor (vWF) were determined. The possible effect on plasma or platelets was examined by blood compositions containing citrated whole blood after ingestion of ASA plus either plasma or platelets after application of DDAVP (control: plasma or platelets after ASA). Excellent correlations were found between BT and IVBT as well as vWF (r2 = 0.97-0.99). In contrast, platelet aggregation decreased after administration of DDAVP. Experiments with blood compositions showed an effect of plasma and platelets as well in the IVBT after DDAVP administration. The results demonstrate the superiority of the IVBT to describe the in vivo function of platelets in comparison with the platelet aggregation test.