The bleeding time as a test of hemostatic function.

The vascular component of hemostatis is determined by the bleeding time as designed by Duke or by the Ivy modification, which is a combined bleeding time-tourniquet test. A prolonged bleeding time is observed: (1) in thrombopathic thrombocytopenia, which may be (a) hereditary or (b) acquired, as in the immune types or from depression of bone marrow, and (2) athrombocytopenically, as in von Willebrand's disease, Glanzmann's thrombasthenia, or from aspirin intolerance. The role of a specific bleeding time determinant in the plasma (labile bleeding time factor of Perkins) is discussed and its possible relation to platelets suggested.