# How do I recalculate flow rates for infusions? - page 2

by EmilyEmily

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1. An IV of 500mL was ordered to infuse in 3 hr using a 15gtt/mL set. With 1 1/2 remaining, you discover that only 150 mL is left in the bag. At what rate will you need to reset the flow? 2. An IV of 1000mL was ordered to... Read More

- 1Jan 22, '13 by
*akulahawkRN*Simple math. Do the stuff in parenthesis first, left to right...

150mL/90 min = 1.67 mL/min. Then multiply by the gtt factor.

1.67 mL/min * 15gtts/mL = 25 gtts/min.

As to why we weren't helping that much is that we generally prefer to point the way to the solution and if you follow the pointing, you'll arrive at the solution yourself and understand the result much more concretely than if we spoon feed you the answer.mariebailey likes this. - 0Jan 22, '13 by EmilyEmilyQuote from akulahawkThat method does not work for everyone. I like for someone to work the problem out so that I can see all of the steps and how it was solved. Maybe there was a step that I missed. This forum was made to assist students so I expect people to want to actually helpSimple math. Do the stuff in parenthesis first, left to right...

150mL/90 min = 1.67 mL/min. Then multiply by the gtt factor.

1.67 mL/min * 15gtts/mL = 25 gtts/min.

As to why we weren't helping that much is that we generally prefer to point the way to the solution and if you follow the pointing, you'll arrive at the solution yourself and understand the result much more concretely than if we spoon feed you the answer. - 0Jan 22, '13 by Mina E.Quote from EmilyEmilyThis is how I learned how to do flow rates in my Medical Dosage Calculations class and how I used to do it when I was a pharmacy tech. Now that I am in the ADN program, I still do it the same way. So I wasn't aware I was missing steps. The way I posted it has all the steps, in my opinion.That method does not work for everyone. I like for someone to work the problem out so that I can see all of the steps and how it was solved. Maybe there was a step that I missed. This forum was made to assist students so I expect people to want to actually help
- 0Jan 22, '13 by EmilyEmily(400ml/3hr)(1hr/60min)(20gtts/ml)= 44.4gtts/ml or about 44gtts/ml

Over 15secs, you would count 11gtts

I dont understand how you got 44 from that equation. can you break it down for me? - 0Jan 22, '13 by
*akulahawkRN*Oh, and I missed a small step: how many gtts in 15 seconds. Answer: approximately 7. (25/2)/2=6.5 gtts/15 seconds.

I calculate the rate per minute and then determine the gtt rate/min from that. When I need to answer a rate/hour, I just calculate that instead. It's just some basic math stuff. - 1Jan 22, '13 by Mina E.Quote from EmilyEmily400/3= 133.33

so anything over 15 seconds makes it 11/gtt?

I dont understand how you got 44 from that equation. can you break it down for me?

1/60=0.0166

20/1=20

133.33x0.0166x20=44.26

It should be 44gtts/min. My previous answer said 44gtts/ml.

1min=60sec

60sec/15secs=4

44/4=11

11gtts/15sec

All you have to do is the math inside the parentheses and you will get your answerEmilyEmily likes this. - 3Jan 22, '13 by
*Esme12***Asst. Admin**Quote from EmilyEmilyHI! Welcome to AN! We are happy to help with homework.....but we won't do it for you. Everyone has been very helpful to you and given you plenty of information. I always ask for what you have done so far so I can best help you k now where you are going awry so I cab best help you stay in the right track.That method does not work for everyone. I like for someone to work the problem out so that I can see all of the steps and how it was solved. Maybe there was a step that I missed. This forum was made to assist students so I expect people to want to actually help

Yes, this forum was made to help students...but it also states**This is NOT the forum to ask someone to do your homework for you. When asking for assistance with an assignment, please show what you have done first**.

The site that someone gave you earlier in the thread is an important one and a valuabvle one especially for students.

Formula: for gtt(drop)factor

__Volume (mL)__Time (min) x Drop Factor (gtts/mL) = Y (Flow Rate in gtts/min)

- 1Jan 22, '13 by
*Esme12***Asst. Admin**Quote from EmilyEmilywatch you conversions. Most problems have several steps....first..what is the question asking.Wait I still don't see how you got 25 for this one..I'm getting 9An IV of 500mL was ordered to infuse in 3 hr using a 15gtt/mL set.**With 1 1/2 remaining, you discover that only 150 mL is left in the bag**. At what rate will you need to reset the flow?

You now have only 150cc's of IVF left and that need to infuse over 1 and 1/2 hour. HOw many minutes are in 1 and 1/2 hour.....(if there are 60 min per hour how many min are in 1 1/2 hour?) YThe are 90 min in 1 1/2hour.

so I have 150cc of IVF that needs to infuse over 90 min.Formula:

__Volume (mL)__Time (min) x Drop Factor (gtts/mL) = Y (Flow Rate in gtts/min) __150cc__

90min X 15 =

so 150 divided by 90 equals...What?...multiply that times the drop(gtt) factor of 15 and you get the new pump setting to infuse that 150cc one 1 and 1/2 hour.Last edit by Esme12 on Jan 22, '13EmilyEmily likes this.