New Nursing Student-- IV calculation questions?

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Hi Everyone! I am about to start my accelerated nursing program soon, and I'm extremely excited and nervous. I was given a pre-worksheet on dosage calculations to do, and I am slightly overwhelmed because I'm not so great in math. I have gotten all of my questions right, except I am having trouble with one problem, and I was hoping someone could help me with the formula to figuring it out? The questions is regarding an IV infusion that was started at 9AM at 50 drops/minute, and the set delivers 60 drops/mL. After two and a half hours (11:30), how many mL of fluid should have been infused so far?

I'm coming up with 100mL, but I'm not sure if I did my calculations correct. Any advice would be greatly appreciated!

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If you can get a hold of a pharm book like "calculating with confidence" that's what really helped me! Just practice as much as you can- learn dimensional analysis- it really helps with these, and you'll do fine!

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I came up with 50 ml per hour, times 2.5 hours is 150 ml I think...doing it in my head tho.

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Hi and thank you for the suggestions. I will definitely look into that book. In regards to the problem, I had a friend help me, and we did 50 drops/min times 150 mins divided by 60 drops/mL, and we came up with 125mL infused so far.

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Specializes in Pedi.
Hi and thank you for the suggestions. I will definitely look into that book. In regards to the problem, I had a friend help me, and we did 50 drops/min times 150 mins divided by 60 drops/mL, and we came up with 125mL infused so far.

You are correct.

50 drops/min x 60 min/hr = 300 drops/hr divided by 60 drops/mL = 50 mL/hr. For two and a half hours, that would be 125 mL.

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Specializes in Critical Care, ED, Cath lab, CTPAC,Trauma.
DosageHelp.com - Helping Nursing Students Learn Dosage Calculations is a great site...:) AND for dimensional analysis....http://www.davesems.com/files/drug_dose_calculations.pdf
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khans academy is AWESOME for D.A. questions.

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I always recommend stopping and drawing pictures to get a feel for the problem before you start flailing around in fear of setting up an equation wrong. Often that can settle you down and give you a ballpark idea of the magnitude of the answer.

In this case, you might think to yourself, Hmmm.... if there are 60gtts/cc, and if the thing were running at 60gtts/min, then I'd be giving one cc per minute, and in two and a half hours, that'd be, lessee here, 150 minutes, 150cc.

But it's running slower than that, at 50gtts/min, so my answer is going to have to be less than 150cc, isn't it?

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i got 150

50/60= .83mls/min is being delivered

.83 x 180 (the total number of minutes) = 150mls

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This is how I would do it:

2.5 hrs x 60 min/hr x 50 gtt/min x 1mL/60ggt = 125 mL :D

Didn't know this was called dimensional analysis, but that's what it seems to be referred to here! This is how I do ALL my drug calculations

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i got 150

50/60= .83mls/min is being delivered

.83 x 180 (the total number of minutes) = 150mls

Not 180 minutes. 2.5 hrs = 150 minutes.

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Not 180 minutes. 2.5 hrs = 150 minutes.

oh yes! you are right. .83 X 150 min = 124.5mls :)

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