Search results
Results From The WOW.Com Content Network
The partial thromboplastin time (PTT), also known as the activated partial thromboplastin time (aPTT or APTT), is a blood test that characterizes coagulation of the blood.A historical name for this measure is the Kaolin-cephalin clotting time (KCCT), [1] reflecting kaolin and cephalin as materials historically used in the test.
Clotting time is a general term for the time required for a sample of blood to form a clot, or, in medical terms, coagulate.The term "clotting time" is often used when referring to tests such as the prothrombin time (PT), activated partial thromboplastin time (aPTT or PTT), activated clotting time (ACT), thrombin time (TT), or Reptilase time.
The reference range for prothrombin time depends on the analytical method used, but is usually around 12–13 seconds (results should always be interpreted using the reference range from the laboratory that performed the test), and the INR in absence of anticoagulation therapy is 0.8–1.2.
These tests include prothrombin time (PT/INR), activated partial thromboplastin time (aPTT), albumin, bilirubin (direct and indirect), and others. The liver transaminases aspartate transaminase (AST or SGOT) and alanine transaminase (ALT or SGPT) are useful biomarkers of liver injury in a patient with some degree of intact liver function.
If the problem is a simple factor deficiency, mixing the patient plasma 1:1 with plasma that contains 100% of the normal factor level results in a level ≥50% in the mixture (say the patient has an activity of 0%; the average of 100% + 0% = 50%). [3] The PT or PTT will be normal (the mixing study shows correction).
The aPTT-based APC resistance test involves a modified aPTT test performed in the presence and absence of activated protein C (APC). [1] [5] The ratio of these aPTT values is calculated and is called the APC sensitivity ratio (APCsr) or simply APC ratio (APCr). [1] [5] This ratio is inversely related to the degree of APC resistance. [7]
For premium support please call: 800-290-4726 more ways to reach us
The contact activation (intrinsic) pathway is initiated by activation of the contact activation system, and can be measured by the activated partial thromboplastin time (aPTT) test. [ 49 ] The tissue factor (extrinsic) pathway is initiated by release of tissue factor (a specific cellular lipoprotein), and can be measured by the prothrombin time ...