PTT & APTT - Differences? - page 2

Other than the normal values, what is the difference between the APTT and the PTT? Since the lab values are difference, I would "assume" that there has to be some different between the two, other... Read More

  1. by   sickofstudying
    let me give you a scenario to see if i've got it. If the control on a ptt test is 35 and the result is 50 since it could be 1.5-2.5 times the control when on heparin would that mean that the person would receive more heparin? thanks, kinda confused.
  2. by   Deidra36
    Cool, that works for are the antidotes administered normally? By which route?
  3. by   Daytonite
    Protamine, the heparin antagonist, is given IV.
    Vitamin K (phytonadione), the warfarin antagonist, is given orally, subcutaneously or IM.
  4. by   rbrychckn
    Thought I'd add a different look at PTT vs aPTT as I learn it (even though this was answered back in 2004)

    PTT is the old test that adds Partial Throboplastin to blood in order to mimic the contribution that platelets provide in the body (specifically, plasma membrane phospholipids). Once added, the test measures the time it takes to clot. The problem with PTT was that the PTT time included the variable timeframe where the clotting factors needed to come into contact with each other and become 'activated' and begin clot formation.

    So PTT was modified to aPTT to remove this variable time-to-activation by adding factors to completely activate your blood sample before you start timing clot formation. You strip away the variable time to activation, which is not really what the test is trying to measure. We want to know how long it takes to form a clot from the time the "clot switch" has been flipped on.

    This is the major reason why PTT normals [roughly 60-70 sec] are longer than aPTT normals [roughly 25-40ish] but in the whole scheme of things, both are testing for abnormal clotting times via the intrinsic pathway (either too short or too long, usually the latter). Hope that helps make sense of it all.
    Last edit by rbrychckn on Oct 30, '08 : Reason: Edit for grammar
  5. by   thatindiangurl
    omg I love you guys :-)
  6. by   UM Review RN
    Quote from heartjulz
    excellent source for info.


    lovenox, also called enoxaparin, is a form of heparin called fractionated heparin. lovenox does not require monitoring of its blood levels and it can be injected intramuscularly. people with chronic kidney disease should not use lovenox as poor kidney function makes lovenox accumulate in the blood. the side effects of lovenox include skin irritation at the site of injection and nausea.
    i don't wanna nitpick, but are you sure about that? lovenox is usually given subq and never im because muscle is so much better perfused than the sq and more likely to result in a hematoma.
  7. by   cardiacRN2006
    I've never given lovenox IM, nor have I ever seen that...

    Just look at the size of the needle, it's clearly meant for SubQ.
  8. by   troydaby
    i thank u a lot, all of you guys... really need this info much... god bless
  9. by   robert odoi
    it is just simple,for ptt and aptt,they might be the same but for the fact that they have different value as the

    question says should tell u there is a some sought of difference.

    The reason why they have differnt value is because ptt and aptt uses different chemicals in it testing processes

    that accelerate or activate the clooting factorredbeathe