Thrombin Time
Also known as: Thrombin Clotting Time (TCT)
Use
Diagnose fibrinogen deficiency, both congenital and acquired;6 identify heparin contamination of samples and direct thrombin inhibitor therapy.
Special Instructions
If the patient's hematocrit exceeds 55%, the volume of citrate in the collection tube must be adjusted. Coagulation Collection Procedures should be referred to for detailed guidance. Patients should ideally not be on anticoagulant therapy before the test, and certain therapies like warfarin should be avoided prior to testing.
Limitations
Thrombin time will be extended when functional fibrinogen levels are below 100 mg/dL due to various congenital and acquired conditions. Thrombin inhibitors including heparin, argatroban, and hirudin will cause an extended thrombin time. Proper handling and processing of specimens are crucial to prevent false results, e.g., severe hemolysis, improper labeling, clotted specimen can lead to sample rejection.
Methodology
Other
Biomarkers
LOINC Codes
- 3243-3
- 3243-3
Result Turnaround Time
2-3 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1 mL
Minimum Volume
Not provided
Container
Blue-top (sodium citrate) tube
Collection Instructions
Citrated plasma samples should be collected by double centrifugation. Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate. Evacuated collection tubes must be filled to completion. Immediately mix by gentle inversion at least six times. Centrifuge for 10 minutes and carefully remove 2/3 of the plasma with a plastic transfer pipette. Deliver to a plastic transport tube, cap, and recentrifuge for 10 minutes. Transfer the plasma into a Labcorp PP transpak frozen purple tube with screw cap. Freeze immediately and maintain frozen until tested.
Patient Preparation
Ideally the patient should not be on anticoagulant therapy. Avoid warfarin therapy for two weeks prior and heparin for three days prior to testing.
Storage Instructions
Freeze.
Causes for Rejection
Severe hemolysis; improper labeling; clotted specimen; specimen diluted with IV fluids; samples thawed in transit; improper sample type; sample out of stability.
Stability Requirements
| Temperature | Period |
|---|---|
| Frozen | 28 days |