PTT
From Health Facts
Latest Edit: Hector 2014-03-24 (EDT)
See Also | Lab Tests |
---|
The PTT, or Partial Thromboplastin Time test used to assess the intrinsic system and the common pathway of clot formation. It is also used to monitor heparin therapy. [1], [2]
Discussion
- PTT evaluates factors I (fibrinogen), II (prothrombin), V, VIII, IX, X, XI, XII involved in clotting.
- Nearly all hemostatic abnormalities can be recognized when the PPT is combined with the prothrombin time.
- On the other hand, heparin has been found to inactivate prothrombin (factor II) and to prevent the formation of thromboplastin.
Patient Preparation
- No fasting required.
- Factors which can cause increased levels
- Drugs: antihistamines, ascorbic acid, chlorpromazine, heparin, and salicylates.
- Factors which can cause decreased levels
- None noted
Clinical Implications
High levels indicate:
- Congenital clotting factor deficiencies (e.g. von Willebrand disease, hemophilia, hypofibrinogenemia)
- Cirrhosis of the liver
- Vitamin K deficiency
- Diseeminated intravascular coagulation (DIC)
- Heparin administration
- Coumarin administration
Low levels indicate:
- Early stages of DIC
- Extensive cancer
Associated Tests
- Bleeding time, Thrombin time, Prothrombin Time, Coagulating Factor Concentration
References
- ↑ Pagana Kathleen D, Pagana Timothy J (2006) Mosby's Manual of Diagnostic and Laboratory Tests, Mosby.
- ↑ Weatherby Dicken, Ferguson Scott (2002) Blood Chemistry and CBC Analysis: Clinical Laboratory Testing from a Functional Perspective, Bear Mountain.