[Quantitative bleeding time].

Bleeding time, which reflects the interaction of the platelets with the damaged vessel wall and the subsequent formation of the primary hemostatic plug, has been widely used in the diagnosis of bleeding disorders, especially platelet abnormalities. We have developed a computerized method to measure the bleeding pattern and the amount of blood loss from the bleeding time incision (quantitative bleeding time). In 87 normal subjects (51 males and 36 females), the bleeding time was 389 +/- 137 sec and the amount of blood loss was 15.7 +/- 7.2 microliters (mean +/- S.D.). The bleeding pattern was classified into four types (I-IV). Type II showed the prolongation of the bleeding time, continuous constant bleeding, and considerably large amount of blood loss from the incision. This type which includes severe von Willebrand disease and serious thrombocytopenia is related to the severe bleeding tendency. Type III exhibited the prolongation of the bleeding time keeping a trace of blood loss from the incision. In type III patients, the bleeding tendency was generally mild despite the prolonged bleeding time as in patients with moderate thrombocytopenia or aspirin ingestion. Measurement of bleeding pattern and blood loss will provide a useful information to evaluate the defect of primary hemostasis.