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Heparin Math

Posted
MarySnov MarySnov (New) New

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

loveofrn, BSN, RN

Specializes in MICU. Has 3 years experience.

There's no formula. It is a basic math. I think you should post a question that is difficult for you maybe we can help you out on how to solve it step by step

Students always want to cram all available numbers into formulas (of which DA is one, BTW). They often end up throwing every number in the word problem into the formula willy-nilly, and get some outlandish answer, and get crazed. The people who write the questions know this, and so they always put in a few choices that are wrong but that will be obtained if the formula is used without really knowing what it means.

If you took and passed algebra in high school, you can figure out these word questions.

How about you give us a sample of one you got stuck on, show us what you tried to do, and let us help you see where you went wrong?

KelRN215, BSN, RN

Specializes in Pedi. Has 10 years experience.

There is no formula. Heparin comes in many concentrations and patients are on heparin for a variety of reasons. There is simply no formula you can apply to every IV heparin order.

Hi,

Thank-you all for your help. I don't have any problems yet, so I don't have one to post. We haven't actually started this portion of the class yet. I was just trying to do a little prep learing before we actually have our IV calculations class. I appreciate the website to.

Mary :)

Well, here's a little heparin primer...

Heparin is an anticoagulant... meaning it prevents clots from forming or worsening...

Heparin is a high-risk medication... too much and you're going to have a patient bleeding out... it can also cause thrombocytopenia (HIT)... Don't screw around with heparin because it can kill...

Heparin requires regular monitoring of coagulation labs and adjustment of the dose to maintain the desired coag status.

Heparin is a weight-based medication that is dosed in units per kilogram.

Heparin is often given as a bolus (a set amount given over a few minutes)... also known as a "loading dose" followed by a drip...

The bolus dose is a single number... a given number of units (that is u/kg x kg body weight)

The drip is a *rate*... (u/kg x kg) per hour...

When the coags are taken, the drip is often modified up or down.

The kinds of equations that you need to work with include...

+ converting between kilograms and pounds... that is, 1 kg = 2.2 lb or conversely, 1 lb = 0.454 kg

+ utilizing heparin concentration to determine the volume flow rate... that is, the mL/hr...

+ utilizing tubing drip factor to determine the drip rate... drops per minute (gtt/min)

+ converting a weight-based dose to a specific dose (that is, multiplying the pt's body weight by the weight-based dose)

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?

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.

loveofrn, BSN, RN

Specializes in MICU. Has 3 years experience.

Am starting NS school this fall, so I think I know the answer to the first one

The counteracting agent would be P. Sulphate which must be given for every ml of the heparin overdose given. P. Sulphate promote coagulation. I learned this during my AP 2

Esme12, ASN, BSN, RN

Specializes in Critical Care, ED, Cath lab, CTPAC,Trauma. Has 41 years experience.

Yes it's protamine sulfate. Actually it is 1mg of protamine for every 100 units of heparin....with a max dose of 50mgs.

loveofrn, BSN, RN

Specializes in MICU. Has 3 years experience.

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

Thanks

Esme12, ASN, BSN, RN

Specializes in Critical Care, ED, Cath lab, CTPAC,Trauma. Has 41 years experience.

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/

KelRN215, BSN, RN

Specializes in Pedi. Has 10 years experience.

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.

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?

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?

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.

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

I'll never tell... :D