PTT & APTT - Differences?

[kate930]

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 than the name. All I find is that PTT is also called APTT, however, this really confuses me since their normal values are very different.

What would you use one for, but not the other?

Thanks! :)

[HeartJulz]

excellent source for info.

http://stroke.about.com/od/caregiverresources/a/blood_thinners.htm

lovenox

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.

[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.

[Deidra36]

Cool, that works for me...but...how are the antidotes administered normally? By which route?

Thanks!

[Daytonite, BSN, RN]

Protamine, the heparin antagonist, is given IV.

Vitamin K (phytonadione), the warfarin antagonist, is given orally, subcutaneously or IM.

[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.

[thatindiangurl]

omg I love you guys :-)

[UM Review RN, ASN, RN]

heartjulz said:

excellent source for info.

http://stroke.about.com/od/caregiverresources/a/blood_thinners.htm

lovenox

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.

http://www.aahcp.org/dvt/faqs.htm

[cardiacRN2006, ADN, RN]

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.

[troydaby]

i thank u a lot, all of you guys... really need this info much... god bless

[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 factor:heartbeat:redbeathe:yeah: