II. Background
- Evaluates Intrinsic Clotting Pathway integrity
- Plasma collected in a tube containing citrate, which binds Calcium and prevents initial clotting
- Calcium is added back to plasma, and time to clotting is measured
III. Labs: Normal
- Range: 25-41 sec
IV. Causes: Increased
- Heparin
- Warfarin (Coumadin)
- Thrombolytics
-
Clotting Factor deficiency
- Factor I Deficiency
- Factor II Deficiency
- Factor V Deficiency
- Factor VIII Deficiency (Hemophilia A)
- Factor IX Deficiency (Hemophilia B)
- Factor X Deficiency
- Factor XI Deficiency
- Factor XII Deficiency
- Liver disease
- Vitamin K Deficiency
- Disseminated Intravascular Coagulation (DIC)
- Circulating Anticoagulants or specific factor inhibitor
- Penicillin reaction
- Rheumatoid Factor