Hemostasis Reference Laboratory

Thrombin Time

• Transaction Code: 3200-02
• CPT Code (Suggested): 85670

A low concentration of thrombin is added to plasma and the rate of reaction for the conversion of fibrinogen to fibrin is measured in seconds. The enzymatic cleavage of fibrin peptides is rate limiting because of the low concentration of thrombin. Prolongation of thrombin time can be caused by heparin, elevated levels of fibrin/fibrinogen degradation products (FDP), hereditary or acquired fibrinogen abnormalities (hypofibrinogenemia or dysfibrinogenemia), or the presence of fibrinolytic agents (e.g., streptokinase, urokinase).

• Sample Required: 0.5 ml frozen plasma x4 or (2) 3.2% sodium citrated tubes, 5 ml each.
• See Sample Requirements when ordered with other tests.
• Normal Range: 18.0-24.0 sec
• Analytic Time: Within 5 working days