[marilynmom]

I have been working in a PICU for a year now as a nurse tech/extern. I just formally accepted working there as an RN starting in June.

What is the fastest way to do the mcg/kg/min (or hour I think our pumps are set per hour) calcs? I feel like I am slow figuring them out and someone mentioned to me I do it the long way (that is just the way I learned it). I don't want to rely on the pumps to do the math for me.

Anyways, what is the formula you use??

Thanks!

[kessadawn]

Okay, here's how we do it. Although, our IV pumps are smart pumps, and that cuts WAY back on med errors.

Let's say you are going to start a dopamine gtt on a 10kg patient. The order reads:

"dopamine 5mcg/kg/min"

your concentration is 3200mcg=1cc

here's the math:


(dose ordered) X (pt weight in kg) X (minutes)
__________________________________________ = (rate of pump)

(amount of mcg in 1cc)


OR:

5 X 10 X 60
-------------- =0.9375cc/hr
3200

Hope that helps!

Oh, and the rate of the pump will always run as cc's/hr, even if your med is ordered minutes. Dopamine, epi, norepi, pressors always ordered mcgs/kg/min. Other gtts such as bumex, lasix, morphine, versed, always orders in hours. It seems like a lot of info, I'm sure, but as you use it every day, you'll get it. Congrats on your new job!

[judytheoldrn]

Hey that was a good answer, Kessa! I would have given a slightly longer one, but basically the same once the units are cancelled out:

mcg/kg/min x kg = __ mcg/min, then:
__ mcg/min x 60min/hr x cc/mcg = cc/hr

5mcg/kg x 10kg = 50mcg, then:
50mcg/min x 60min/hr x 1cc/3200mcg = 3000cc/3200mcg = .937 cc/hr.

This way you see right away where all the units went and you know you have the right units at the end before you even plug in the numbers.

[NSUNurse2b]

Originally Posted by kessadawn

Okay, here's how we do it. Although, our IV pumps are smart pumps, and that cuts WAY back on med errors.

Let's say you are going to start a dopamine gtt on a 10kg patient. The order reads:

"dopamine 5mcg/kg/min"

your concentration is 3200mcg=1cc

here's the math:


(dose ordered) X (pt weight in kg) X (minutes)
__________________________________________ = (rate of pump)

(amount of mcg in 1cc)


OR:

5 X 10 X 60
-------------- =0.9375cc/hr
3200

Hope that helps!

Oh, and the rate of the pump will always run as cc's/hr, even if your med is ordered minutes. Dopamine, epi, norepi, pressors always ordered mcgs/kg/min. Other gtts such as bumex, lasix, morphine, versed, always orders in hours. It seems like a lot of info, I'm sure, but as you use it every day, you'll get it. Congrats on your new job!

Is the 3200mcg=1cc a constant? I haven't graduated yet, but we didn't really learn any calculations for peds so forgive me if my question is dumb. Thanks

[kessadawn]

NSUNurse,

Not a dumb question at all!

Our gtts are figured using a standard concentration book. The concentration of each drug depends on the weight of the patient, 5kg or less, 5- 20 kg, or 20kg or greater, I think. For example, we mix a versed gtt for a larger child using a 1mg=1cc concentration, but for a 2 kg baby it would be 0.5mg=1cc. 3200mcg=1cc concentration for dopamine is a standard premix for dopamine at my facility, used for the bigger kids. The only variation on these formulas in the book comes when you have a patient on strict fluid restriction, then our attending can write orders to concentrate the gtts even further.

[kessadawn]

Originally Posted by judytheoldrn

Hey that was a good answer, Kessa! I would have given a slightly longer one, but basically the same once the units are cancelled out:

mcg/kg/min x kg = __ mcg/min, then:
__ mcg/min x 60min/hr x cc/mcg = cc/hr

5mcg/kg x 10kg = 50mcg, then:
50mcg/min x 60min/hr x 1cc/3200mcg = 3000cc/3200mcg = .937 cc/hr.

This way you see right away where all the units went and you know you have the right units at the end before you even plug in the numbers.

I think this is they way we were taught in nursing school, I've done it my way for so long, at first I really had to think about the way you figured it out! Can't teach an old dog new tricks, I guess!

[NSUNurse2b]

Originally Posted by kessadawn

NSUNurse,

Not a dumb question at all!

Our gtts are figured using a standard concentration book. The concentration of each drug depends on the weight of the patient, 5kg or less, 5- 20 kg, or 20kg or greater, I think. For example, we mix a versed gtt for a larger child using a 1mg=1cc concentration, but for a 2 kg baby it would be 0.5mg=1cc. 3200mcg=1cc concentration for dopamine is a standard premix for dopamine at my facility, used for the bigger kids. The only variation on these formulas in the book comes when you have a patient on strict fluid restriction, then our attending can write orders to concentrate the gtts even further.

Thank you so much for explaining that to me!

[RNNPICU]

There are two standard concentrations one is low dose Dopa which is 800mcg/kg/min and the other is high concentration which is 3200mcg/kg/min.

I ALWAYS use the formula starting dose mcg X weight (kg) X 60
--------------------- ----
concentration (800 or 3200)

It gets easier with practice.

[marilynmom]

Thanks so much!

This is an area where I just need practice with basically, I am soooo slow and the RNs I work with seem to fast with figuring the rates out! I know it will just get easier with time though and that is ok

[irisRN]

It truly comes with practice. occasionally my brain freezes over, especially when dealing with nanograms, LOL.

i do the good old: mcg x kg x 60 x volume in mL/concentration in mcgs.

So, for example...Milrinone...we use 20 mg in 100 mL. If the order reads 0.5 mcg/kg/min, and your kid weighs 10 kg, you go:

0.5 x 10 x 60 x 100/20000 (convert mg to mcg, so 20 x 1000).

This is the same as was mentioned earlier...