Thrombin time
What is being analysed?
Thrombin time (TT) is a laboratory test that measures the time it takes for a fibrin clot to form after the addition of thrombin to plasma.
What does the result mean?
The result of thrombin time indicates the functionality of the final step of the coagulation cascade, specifically the conversion of fibrinogen to fibrin by thrombin.
Why do the analysis?
Thrombin time analysis is crucial in diagnosing clotting disorders, monitoring anticoagulant therapy, and evaluating bleeding disorders such as liver disease or disseminated intravascular coagulation (DIC).
When to do the analysis?
Thrombin time is typically ordered when a patient presents with unexplained bleeding or clotting symptoms, or to monitor patients on anticoagulant therapy.
What sample is required?
A sample of blood plasma is required for thrombin time analysis.
Is any type of prior preparation necessary?
No specific prior preparation is usually necessary for thrombin time analysis. However, it's important to follow any instructions provided by the doctor or laboratory.
How is it used?
Thrombin time is used to assess the overall functionality of the coagulation cascade, particularly the conversion of fibrinogen to fibrin. It helps in diagnosing and monitoring various bleeding disorders and assessing the efficacy of anticoagulant therapy.
What are the normal values?
Normal thrombin time values typically range between 14 to 16 seconds. However, reference ranges may vary slightly depending on the laboratory method used.
What does it mean to have altered values?
Abnormal thrombin time values may indicate a variety of conditions:
Prolonged thrombin time may suggest deficiencies in fibrinogen, dysfibrinogenemia, or the presence of heparin.
Shortened thrombin time may indicate elevated levels of fibrinogen, hypercoagulable states, or the presence of fibrinogen degradation products.
Thrombin time values table:
Age Group |
Normal Thrombin Time (seconds) |
Adults |
14 - 16 |
Children |
Slightly shorter than adults |
Understanding thrombin time and its significance in assessing coagulation disorders is crucial for accurate diagnosis and effective management of patients with bleeding or clotting tendencies. If you have any concerns about your thrombin time results, consult with your healthcare provider for further evaluation and guidance.