IV Calculation math help

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i been trying to figure this problem out for the life of me and I googled and still no luck. I want to know how to set up a formula when an IV rate is increased or decreased.

The doctor orders 500 mL D10W to infuse at 75 mL/hr. The nurse start the IV at 1330. At 1530 the IV rate is increased to 100 mL /hr, per doctors order. Starting with the amount of IV Fluid remain at 1530, calculate the new infusion time and completion time of the IV.

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Specializes in Acute Care, Rehab, Palliative.

Ok so you started with 500ml and ran it for 2 hours at 75mls an hour. What do you have left? Then it increased to 100mls an hour. How long would it take for the remainder to infuse?

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Do you have 350 ml left from if it infused 75ml/hr over 2 hours

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Do you have 350 ml left from if it infused 75ml/hr over 2 hours

350ml/100ml = 3.5 or 3hr 3min

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Specializes in Acute Care, Rehab, Palliative.

3 hours and 30 minutes

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Specializes in Hospitalist Medicine.

75 mL/hr, ran for 2 hours = 150 mL infused.

500-150 = 350 mL remaining to be infused.

The new rate is 100 mL/hr.

(1 hr/100 mL) x 350 mL = 3.5 hr

Does that make it more clear?

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yes that makes it more clear i appreciate your help i have a IV med math test tomorrow

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There is not *a* formula to solve this problem. You have to think about what's being asked. The only think you have to think about is what you started with, how much went in, and how much is left when you have to recalculate.

This is the problem with formulae. So often I see students try to cram every possible bit of data in the question into an equation...and a lot of it is not needed for the answer. Does make for a lot of unnecessary confusion.

We see people here all the time that can't read a problem, see which data points are needed and which are distractors/extraneous, and they cram all of it into a big dimensional analysis thing, or some other "sure-fire formula," and come up with a nonsensical answer, and then get flustered and confused. The people who write exams know this, and so they give distractors (wrong answers) that will result when numbers are slotted into formulae without understanding, knowing that some people will pick them because they have no idea to think about the problem. So I prefer to get people to back away, slowly, from the formulae and think about what is going on, what's really being asked, and look at what they know before they start getting flustered about OMGIHAVETOSOLVEAPROBLEM!!!!! :)

Here's another really good thread to help you take that step back and think before you act. As our beloved Swami Beyondananda says, "Don't just do something! Sit there!"

https://allnurses.com/nursing-student-assistance/dosage-calculation-question-898310.html

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Thank you GrnTea and everyone that helped me for the helpful information I will read the article and btw I passed my med IV calculation test today now I need to study for my HTN and Diabetes theory quiz.

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