Does the choice of thromboplastin affect the measured prothrombin time and recommended therapeutic range in patients on oral anticoagulants?
Different thromboplastins yield widely varying prothrombin times, highlighting the critical need for standardization to safely manage oral anticoagulant therapy.
Six trromboplastins commonly used for prothrombin time determinations were studied. Prothrombin times of patients who were receiving oral anticoagulant therapy varied widely, depending on the origin of the thromboplastins. The therapeutic range which is recommended with one thromboplastin is often quite different from that recommended with another, and as a result, the therapeutic ranges of different institutions may show no overlap. Management of patients and comparison of therapeutic results would be facilitated if all thromboplastins in use in Australia were standardized by comparison with the Australian Reference Thromboplastin.
Bain et al. (Wed,) studied this question.