Evaluate an isolated prolonged PT and document factor VII deficiency
Direct Xa or thrombin inhibitor therapy may cause factitiously low results.
Frozen
Prothrombin Time (PT)-based one-stage clotting time assay. Factor VII- depleted plasma is used as the substrate and the substrate and the clotting time with the patient plasma is compared to the clotting time of normal pooled plasma.
51 - 186%
Direct Xa or thrombin inhibitor therapy may cause factitiously low results.