thrombin time (TT)
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Introduction
The assay is performed adding exogenous thrombin to citrated plasma & measuring the time to clot formation. Normal value:
- time of control +/- 2 sec when control is 9-13 sec
- time of control +/- 5 sec when control is 15-20 sec
Clinical significance
- measures late phase of coagulation
- affected by concentrations of fibrinogen & by the presence of fibrin degradation products
- does NOT distinguish disseminated intravascular coagulation (DIC) from primary fibrinolysis
Increases
- plasma fibrinogen levels < 50 mg/dL or dysfibrinogenemia*
- presence of thrombin inhibitor
- fibrin degradation products (DIC)
- paraproteinemia
- cirrhosis
* may be associated with frequent or severe bleeding[3]
More general terms
More specific terms
Additional terms
Component of
References
- ↑ Clinical Diagnosis & Management by Laboratory Methods, 19th edition, J.B. Henry (ed), W.B. Saunders Co., Philadelphia, PA. 1996, pg 726
- ↑ Guide to Clinical Laboratory Tests, 3rd ed, NW Teitz (ed) WB Saunders, 1995
- ↑ 3.0 3.1 Harrison's Principles of Internal Medicine, 13th ed. Isselbacher et al (eds), McGraw-Hill Inc. NY, 1994, pg 322
- ↑ Medical Knowledge Self Assessment Program (MKSAP) 16, 18. American College of Physicians, Philadelphia 2012, 2018.
- ↑ Panel of 12 tests Laboratory Test Directory ARUP: http://www.aruplab.com/guides/ug/tests/0030181.jsp
- ↑ Thrombin Time Laboratory Test Directory ARUP: http://www.aruplab.com/guides/ug/tests/0030260.jsp
- ↑ Panel of 16 tests Laboratory Test Directory ARUP: http://www.aruplab.com/guides/ug/tests/0030268.jsp
- ↑ Panel of 16 tests Laboratory Test Directory ARUP: http://www.aruplab.com/guides/ug/tests/0000000.jsp