Coagulation Studies

  1. aPTT (Activated Thromboplastin Time)
    20-36 sec.

    Screens for deficiencies and inhibitors of all factors except VII and XIII.

    Used to monitor heparin therapy and screen for coagulation disorders.

    Should be between 1.5 and 2.5 times normal when the client is receiving heparin therapy; if the value is prolonged (longer than 90 sec), the client is at risk for bleeding.
  2. PT (Prothrombin Time)
    • Male Adult: 9.6-11.8 sec
    • Female Adult: 9.5-11.3 sec

    Used to monitor response to warfarin sodium (Coumadin) therapy.

    • To screen dysfunction of the extrinsic clotting system resulting from:
    • Liver disease
    • Vitamin K deficiency
    • Disseminated Intravascular Coagulation (DIC)
  3. Clotting Time
    8-15 minutes
  4. Platelet Count
    150,000-400,000 cells/mm3

    • Factors that incease platelet count:
    • High altitude
    • Chronic cold weather
    • Exercise

    • *Monitor platelet count closely in clients receiving chemotherapy because of the risk for thrombocytopenia.
Card Set
Coagulation Studies
Normal Values