The Relationship between Prothrombin Time and Bleeding in the Clinical Use of Dicumarol after Operation

Experienced clinicians have known for some time that bleeding owing to the use of dicumarol is not entirely a measure of the degree of prothrombin deficiency. This presentation emphasizes that bleeding may occur when prothrombin deficiency is not great and that bleeding may fail to occur when prothrombin deficiency is marked. Nonetheless great prothrombin deficiency causes bleeding more frequently than lesser degrees of prothrombin deficiency. Time is an important factor, for patients are much more apt to bleed when prothrombin deficiency has endured for several days than when it has been present only a day or so.