Help needed on a med math question, please!

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I am hoping there is a smart "mathy" person out there who could help me with this problem:

The physician has written an order for Dobutrex 500 mg in 250 mL of D5W to infuse at 10 mL/hr. The pt weighs 90 kg. How many mcg/kg/min will the pt be receiving?

I have never seen a problem like this, and I'm trying to prepare for my complex math test this week. Any help would be greatly appreciated!!

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find how many mg/hr:

(10ml/hr)/(250ml)*500mg=20mg/hr

now find mcg/min:

(20mg/60min)*1000=333.33mcg/min

to get how many mcg/kg/min divide by kg:

(333.33mcg/min)/(90kg)= 3.70mcg/min/kg

a great website to help is manuel's web: a place to show off his dog click on the nursing link.

hope this helped!

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ambgirl2nurse, thank you so much! It makes total sense now. I just had to see it worked out, but I will know how to work a problem like this if I see it again! Once more, thanks!

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You're welcome!

I'll always be happy to refresh my math skills. I love math, not that great at remembering how to do it though;)

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Here is another one to check out

IV Drip Rate Calculations - Page 1

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Nice. Thanks for the reference, Netglow. My problem is that I can do it as long as I keep doing it. Stop for any length of time (out of school since Oct.) I lose it.

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Yup, I'd have to have a cheat for that one too! I came across that link and filed it away a while ago -- hope it's correct!

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worked like a charm:specs:

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Well, since the problem doesn't specifically state that the medication has to be given at a certain mcg/kg, you can just divide the 90 kg by the infusion rate.

500 mg= 500000mcg/250mL=2000mcg/mL.

10mL/hr= 0.1667 mL/min (just divide by 60)

so, since you have to put in 10 mL/hr (or 0.166667mL/min), you'd have 2000mcg/90kg/0.1666667min = 3.7 mcg/kg/min= 4 mcg/kg/min

I'm pretty sure that's right.

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ahhhh!!! beaten to the punch!

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