Elements from in vitro studies that help understand the action of heparins.

In determining heparin one has the choice to test a specific activity, such as the decay constant of thrombin or factor Xa on a global test such as the aPTT. The best test would be a global test that directly reflects the only important global effect, to wit antithrombotic efficiency. Such a test does not yet exist. We propose that the thrombin potential, i.e. the time concentration integral of thrombin activity appearing in plasma after triggering is a plausible candidate for such a test.