The partial thromboplastin time (PTT) is a performance indicator measuring the efficacy of both the "intrinsic" and the common coagulation pathways. Apart from detecting abnormalities in blood clotting, it is also used to monitor the treatment effects with heparin, a major anticoagulant. It is used in conjunction with the prothrombin time (PT) which measures the extrinsic pathway. This test is also used to detect hemophilia-A, dysfibrinogenemia, vitamin K deficiency, and Christmas disease. PTT is PROLONGED with DIC, lupus anticoagulant, liver failure, vitamin K deficiency, congenital deficiency of Fitzgerald factor, and congenital deficiencies of factors II, V, VIII, IX, XI, and XII.
Separate plasma from cells ASAP and freeze.