thrombin clotting time

Last reviewed 01/2018

The thrombin time is a measure of the rate of conversion of fibrinogen to fibrin when thrombin has been introduced; i.e. it measures haemostatically active fibrinogen. This test is abnormal, i.e. prolonged, in:

  • disseminated intravascular coagulation, as a result of inhibition of fibrin polymerization by fibrin degradation products
  • hypofibrinogenaemia
  • the presence of heparin

Correction of the thrombin time by adding protamine implies that the prolongation was the result of heparin or fibrin degradation products.