Heparin therapeutic range?

[All_Smiles_RN]

I'm in my final semester of nursing school and am unsure of one math problem. I've already conferred with other students and we have not reached a consensus. Hopefully someone here can enlighten us. :)

You find your pt's heparin drip running at 10cc/hr. concentration is 20,000 units in 500 mL D5W. How much hep is pt getting per hour? Simple enough, 400 units/hr. Here's where the uncertainty comes in: Is this within a therapeutic range? I would think yes because 20,000 units is a typical dose, but at that rate it would take 50 hours to receive it all. Is that too long of a time to be therapeutic (book says normally administered over 24hrs)? Wouldn't it depend on the individual pt's pTT? Or do I just forget the rate and look at the dose to determine if therapeutic? Please please point my thinking in the right direction. Thanks!

[NanSeeH]

You are correct in thinking that your answer depends on the individual patients pTT. You would have a lab value to tell you if the patient is within the therapeutic range, if not then there will be an algorhythm for lowing or increase the drip rate (# units)

Hope this helps

[zacarias, ASN, RN]

Just like above, the the aPTT will show if it is therapeutic. Heparin doses vary...for instance a large 350 lbs man may require a much larger dose than someone else to be therapeutic but again we look at the aPTT (or HEPACT in my hospital) to find out if it's therapeutic.

[Spatialized]

I agree with everyone above that there should be a aPTT drawn to match with the protocol, but I had just written up heparin for class and came across this tidbit (which may or may not be helpful); with regards to continuous drips, the rate runs 10-18 units/kg/hr. Of course if you don't have a weight, this is a moot point. At least you could ask you prof. about it in this light...

Cheers,

Tom