Normal range: 26-35 seconds
Comment:This is the most suitable test for monitoring heparin – therapy and evaluation of the intrinsic coagulation system. Prolonged PTT is found in liver disease, coagulation factor deficiencies especially hemophilia, Christmas disease (and sometimes in Von Willebrand’s disease), anticoagulant therapy (including heparin), DIC, lupus anticogulant, and with circulating anticoagulants. Result maybe influenced by extraneous heparin, lipemia, antistreplaser, chlorpromazine and valproic acid
Sample: Citrated whole blood