Heparin Math

Published

Can someone please post the formula for a Heparin IV dose calculation. I don't have any numbers for you. I'm just trying to figure out the math formulas I'll need to know when we have our IV class.

FYI-I really don't like dimensional analysis. I'm better at formulas.

Thanks,

Mary

Specializes in Critical Care, ED, Cath lab, CTPAC,Trauma.

Simply put...Coumadin works by inhibiting the vitamin K dependent coagulation factors. To reverse that effect...you give Vitamin K.

Heparin works in a totally different fashion. It works by binding to antithrombin III (ATIII), which is a natural anticoagulant that acts on a bunch of different factors on both sides of the cascade, but seems to have more of an effect on the intrinsic arm than it does on the extrinsic arm of coagulation. To stop the action of the drug you give the reversal. Protamine will neutralize the antithrombin effect of low molecular weight heparin

http://www.acep.org/Clinical---Practice-Management/Focus-On--Reversal-of-Anticoagulation/

Up Vote Up Vote ×
Specializes in Pedi.
Ohhh pls can you explain why vitamin k cant be effective for heparin but it is for warfarin

Thanks

2 different drugs... they work in different ways. That's why you monitor PTT for Heparin and PT/INR for Coumadin.

Up Vote Up Vote ×
And while we're talking about heparin...

Say you screw up your dosing calcs and bolus your patient with 10x too much heparin... is there a counteracting agent? (hint: *yes*)... what is it?

Are there any potential cultural/religious concerns regarding heparin?

For once I know the answer to both of the questions...and the "why" behind the answer as well LOL. I'll give the OP the opportunity to answer, but then I have a very specific question about this.

So, what's your thought about cultural/religious concerns?

And what's your question?

Up Vote Up Vote ×

Cultural concern is heparin is derived from pig intestinal mucosa, so any culture/religion that can't ingest pork can't use heparin (though I did ask a Muslim friend of mine about it and she said it would be acceptable if choice was heparin or death).

So, when we were covering anticoags in class I asked about this (hadn't talked to my friend yet) and our instructor said anyone who couldn't/wouldn't use heparin would get lovenox instead...I thought lovenox was tweaked heparin but my instructor looked at me like I had a foot growing out of my head so I dropped it. So my question is wouldn't lovenox also be off the table in such a situation?

Up Vote Up Vote ×
Cultural concern is heparin is derived from pig intestinal mucosa
Ding, ding... you got it! I've not personally met any muslims or jews who would refuse heparin but I do believe that they should be made aware prior to its administration.
So, when we were covering anticoags in class I asked about this (hadn't talked to my friend yet) and our instructor said anyone who couldn't/wouldn't use heparin would get lovenox instead...I thought lovenox was tweaked heparin but my instructor looked at me like I had a foot growing out of my head so I dropped it. So my question is wouldn't lovenox also be off the table in such a situation?
Lovenox, or enoxaparin, is a low molecular weight heparin... that is, depolymerized heparin... but still heparin... still porcine derived...

Perhaps your instructor didn't realize that.

Or maybe you really do have a foot growing out of your head.

Up Vote Up Vote ×

Or maybe you really do have a foot growing out of your head.

I'll never tell... :D

Up Vote Up Vote ×
Specializes in Pedi.
Cultural concern is heparin is derived from pig intestinal mucosa, so any culture/religion that can't ingest pork can't use heparin (though I did ask a Muslim friend of mine about it and she said it would be acceptable if choice was heparin or death).

So, when we were covering anticoags in class I asked about this (hadn't talked to my friend yet) and our instructor said anyone who couldn't/wouldn't use heparin would get lovenox instead...I thought lovenox was tweaked heparin but my instructor looked at me like I had a foot growing out of my head so I dropped it. So my question is wouldn't lovenox also be off the table in such a situation?

That's interesting because I have a lot of Jewish and Muslim patients. My primary population is pediatric oncology and ALL of them have some type of central access which is flushed regularly with heparin. I've never heard anyone object to it on religious grounds.

Up Vote Up Vote ×
Specializes in NICU, Trauma, Oncology.
That's interesting because I have a lot of Jewish and Muslim patients. My primary population is pediatric oncology and ALL of them have some type of central access which is flushed regularly with heparin. I've never heard anyone object to it on religious grounds.

But are they aware?

Very interesting. How much pork is too much? Hmm...

And what would a substitute be if there was an objection? Is there one ?

Up Vote Up Vote ×
Specializes in Critical Care, ED, Cath lab, CTPAC,Trauma.

In general, practicing Jews, Muslims, and Seventh Day adventists avoid eating pork or drinking alcohol, and are proscribed from taking medicines that contain alcohol or pig byproducts unless they are life-saving drugs and no substitute is available. Porcine heparin, for example, contains gelatin from pork products, and is the only heparin universally used today. Beef insulin is no longer used here in the US and I am not sure if it is manufactures at all it is expensive and patients seemed to have a greater sensitivity/allergic response.

I found this about religious exceptions

"That was thought to cause a potential problem for Jewish, Muslim, and Seventh-day Adventist patients at this institution," says Doha Hamza, the coordinator of Muslim volunteers at the spiritual care service department at Stanford (CA) University Medical Center. "We investigated the issue with an imam and a Muslim doctor who concurred that the use of porcine heparin is lawful because of the chemical modification the product undergoes and the urgent need involved. Also the amount is so small, it doesn't fit the definition of consumption." Similar solutions might be found for insulin products derived from pork and porcine heart valves.
There was one called Lepirudin but was discontinued by Bayer ad a "business decision" In 2012. Here is what I found

[TABLE=class: rhsvw]

[TR=class: kno-fb-ctx]

[TD=class: ellip]Argatroban

[/TD]

[/TR]

[TR=class: kno-fb-ctx]

[TD=class: ellip]Fondaparinux (Arixtra)

[/TD]

[/TR]

[TR=class: kno-fb-ctx]

[TD=class: ellip]Eptifibatide (Integrilin)

[/TD]

[/TR]

[TR=class: kno-fb-ctx]

[TD=class: ellip]Abciximab

[/TD]

[/TR]

[TR=class: kno-fb-ctx]

[TD=class: ellip]Hirudin

[/TD]

[/TR]

[/TABLE]

Up Vote Up Vote ×
Ohhh pls can you explain why vitamin k cant be effective for heparin but it is for warfarin

Thanks

And this is why when a patient is anticoagulated on heparin (optimized by looking at PTT) you can give him warfarin (Coumadin) without increasing his risk of bleeding. They disrupt totally different parts of the clotting cascade, and for effective clinical anticoagulation you only need to disrupt it in one place. It would be helpful if you go right now and look in your physiology book for the big diagram of the clotting cascade and see those two places.

So. Since nobody goes home on IV heparin, you want to tweak the warfarin dose until it's *just* right. So you check the pro time on various warfarin doses until it's perfect, and then you can just turn off (not wean) the heparin and send the patient out (with, of course, the necessary teaching about diet and pro time rechecks as prescribed).

People always get mixed up on that. Remember they're different drugs with different effects, but you only need the one, remember that nobody goes home on a heparin drip, remember that PTT looks a little bit like an H and pro time has an O in it (like COumadin), and you're good to go. ;)

Up Vote Up Vote ×
Specializes in Pedi.

And this is why when a patient is anticoagulated on heparin (optimized by looking at PTT) you can give him warfarin (Coumadin) without increasing his risk of bleeding. They disrupt totally different parts of the clotting cascade, and for effective clinical anticoagulation you only need to disrupt it in one place. It would be helpful if you go right now and look in your physiology book for the big diagram of the clotting cascade and see those two places.

So. Since nobody goes home on IV heparin, you want to tweak the warfarin dose until it's *just* right. So you check the pro time on various warfarin doses until it's perfect, and then you can just turn off (not wean) the heparin and send the patient out (with, of course, the necessary teaching about diet and pro time rechecks as prescribed).

People always get mixed up on that. Remember they're different drugs with different effects, but you only need the one, remember that nobody goes home on a heparin drip, remember that PTT looks a little bit like an H and pro time has an O in it (like COumadin), and you're good to go. ;)

When I was in nursing school, a nurse at one of my clinicals told me to remember that in Ptt the tt looks like an H and that's how you remember that it's for heparin. It's always worked for me to remember it that way. In fact, when I worked in the hospital, I once drew pre-op Coags off a PICC line and when the PT/INR came back elevated, everyone said "oh it's because it was drawn from a heparinized line"... and the CNS and I were the only ones saying "no, heparin doesn't affect PT/INR."

Up Vote Up Vote ×
+ Join the Discussion