Description
This test measures how long it takes for blood to clot. It is used to evaluate and manage bleeding and blood clotting disorders.
Thrombin is a clotting factor that accelerates or decelerates blood clot formation by promoting or inhibiting its own activation. Thrombin first combines with a protein called thrombomodulin, then activates Protein C. This activated Protein C (APC) then combines with Protein S (a cofactor) and together they work to degrade coagulation factors VIIIa and Va.
Its concentration is measured by means of analysis of a blood sample drawn from the vein in the arm.
Purpose of the test
The purpose of this test is to measure the time necessary for the blood to clot.
This test is prescribed when a coagulation problem is suspected such in:
• Abnormal liver function
• Anticoagulant drug monitoring
• Blood clotting disorder
• Heat stroke
• Hemophilia
• HUS - Hemolytic uremic syndrome
• Obstruction of biliary tree
• Systemic infection
• Vitamin K deficiency
Reference range values
• Adults: 11.1-13.1 seconds
• Neonates: Prolonged by 2-3 seconds
• Premature neonates, 1-3 days old: Prolonged by 3-5 seconds
INR PT ratio
2.5-3.5 mechanical heart valves
2.0-3.0 Prophylaxis and treatment of venous thrombosis, pulmonary embolism, tissue heart valves, acute myocardial infarction, atrail fibrillation, valvular heart disease, and systemic embolization.
Abnormal findings
Abnormal results can be found due to the following subjacent problems:
• Abnormal liver function
• Anticoagulant drug monitoring
• Blood clotting disorder
• Heat stroke
• Hemophilia
• HUS - Hemolytic uremic syndrome
• Obstruction of biliary tree
• Systemic infection
• Vitamin K deficiency