Published
PT and INR come on the same lab work. They are usually a measure of anticoagulation related to coumadin (warfarin). PTT is a measure of anticoagulation related to heparin (usually). I would say that your unit has coumadin and heparin protocols to go by for dosing and adjustments. These labs will tell you how to administer these medications. This is a simplified explanation, there is much more, but this will help your understanding of how these labs relate to your practice. Basically, pts with high PT/INR or high PTT's need to be observed for bleeding. Don't make the newbie mistake of letting them shave with a razor! :)
I just started my new job and STILL can't get a grip on PTT,PT and INR. I couldn't even explain it if my patient was to ask. I've read about them over and over but still have a hard time understanding. So if anyone has a simple explanation I would really appreciate it. OH! A example would probably help out alot too!
It may help for you to think of it like this...
In order for blood to clot properly, a 'cascade' of events has to take place (look up clotting cascade in a&p books, etc.). There are several components to this complicated 'cascade'/process, and i'm not aware of all of them but you can find this info on the net i'm sure...
Anyway, PT (protime/prothrombin time) and PTT (partial thromboplastin time) measure different events/aspects of this clotting cascade...and can give you an idea of how 'thin' your patient's blood is. The reason we check PT with coumadin is because that is the aspect of the clotting cascade affected by it, whereas heparin will affect the PTT portion of the cascade. This is why , for example, you can have dangerously thin blood on coumadin (elevated PT) and still have a normal PTT, or a normal PT but dangerously high PTT because of heparin. Or (as another example)...to make things even more complicated...your blood can be dangerously 'thin' on lovenox and still have a normal PT and PTT...etc.
And you have to remember that PT/PTT can be elevated even when pt is not taking either coumadin or heparin. Certain disease states can cause this (DIC, Liver failure, etc) so you can't assume they're elevated d/t meds if you're unsure.
As far as INR (international normalized ratio) is concerned, i believe it came about because different lab-machines (in different countries???) measured PT a little differently and had a range of varying results depending on the place/machine used. The INR is simply a standardized 'way' of measuring PT...and is more accurate.
I hope that helps a bit...
Holly, first of all, congrats on the new job!! Woo-hoo for you!! :balloons:
Next, I did a http://www.vivisimo.com search and found the following article, which seemed very easy to understand (I hope you find it so too):
http://www.clotcare.com/clotcare/ptinr.aspx
good luck!! (and keep asking questions!)
Holly27
86 Posts
I just started my new job and STILL can't get a grip on PTT,PT and INR. I couldn't even explain it if my patient was to ask. I've read about them over and over but still have a hard time understanding. So if anyone has a simple explanation I would really appreciate it. OH! A example would probably help out alot too!