PT,PTT, INR normal values and medication d/c or increase?

  1. Just want to get normals for pt/ptt/INR

    At what minimum level would you d/c the heparin, coumadin.

    Normal INR: 0.8-1.2. Coumadin d/c at level 3.0 and and start if INR 1. This is example and don't know if right.

    And why is thereapeutic range 2-3 when normal INR is 0.8-1.2. Shouldn't the target of therapy be 1. That is normal. 2-3 is not normal. Does a normal INR cause clotting? Or is 2-3 a better value to prevent clots?

    Some people saying INR is for coumadin, and some say PT. I know INR is a ratio of PT. But on my tests in school it was usually INR for coumadin.

    So if nclex asked a question when to d/c coumadin based on labs, and the answers were a. pt b. INR
    which one would it be?

    All these kinda confusing. I think examples are best. Thanks
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    About jcutler

    Joined: Feb '10; Posts: 48; Likes: 4


  3. by   tnbutterfly
    Coumadin dosage is adjusted as a result of INR. If INR is too high, then Coumadin is decreased.

    Coumadin is an anticoagulant which is used to lower the chance of blood clots. Vitamin K in the diet is normally absorbed by the liver and used as a necessary factor in the production of key clotting proteins. Coumadin impairs the production of liver-dependent clotting proteins. As the concentration of these proteins in the blood decreases, the blood takes longer to clot.

    The dose needed for therapeutic blood thinning is different in each patient. The rate of absorption of the drug, the dietary Vitamin K load, and the livers response to Coumadin does vary from person to person. In order to obtain the clinical anticoagulant effect without overdosage (and subsequent bleeding complications), laboratory tests have been used to monitor the results of Coumadin in each patient.

    For many years, the principal test used to monitor the Coumadin effect was the Prothrombin Time (PT). The International Normalized Ratio (INR) was developed to reduce variability in Pro-Time results. The INR standardizes the methods for comparison amongst different laboratories.

    A patient treated with Coumadin is best managed according to the INR ratio. INR values of 1.0 indicate no Coumadin effect at all. For most clinical conditions, an INR of 2.5 to 3.0 is an appropriate target range. For patients who have a high risk of clot formation, the INR needs to be higher - about 2.5 to 3.5. INR values above 5.0 can be dangerous.

    Most clinical laboratories still report the Pro-Time result along with the INR value, and most doctors and patients still refer to the blood testing as "getting a Pro-Time". However, Coumadin dosage is adjusted according to INR more often than to the Pro-Time result.
  4. by   Mandychelle79
    The easiest way it was explained to me

    Those who have a risk of clots would clot if there INR was at one. So their INR has to be higher ( blood thinner) so it wont clot.
  5. by   jcutler
    Ok thanks. I will just keep it at 2-3 for the INR. Thank so much