Help with math??!

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I've been doing practice questions all day since we must make a 90% or better on our math exam for Med Surg to move on and these are the ones I have been struggling with. Can anyone possibly explain them to me (or even just one of them!? If it was in dimensional analysis even better!

1. A person with a methicillin-resistant S. aureus (MRF) infection is receiving vancomycin IVPB every 12 hours. The medication is available as 1.5 g in 200 mL of D5W to infuse over 4 hours. At what flow rate should the nurse set the IV pump? _____ mL/hr

2. A person with diarrhea is receiving 1 L D5NS with 30 mEq of by potassium chloride (KCl) to infuse at a rate of 1 mEq/hr. At what flow rate should the nurse set the IV pump? _____ mL/hr

3. A person with an abdominal infection is receiving metronidazole (Flagyl) via IV infusion every 8 hours. The medication supply provided by the pharmacy is metronidazole 250 mL to infuse over 90 minutes. The tubing drop factor is 20 gtt/mL. At what rate (in gtt/min) should the nurse regulate the IV infusion?

4. A person with an upper respiratory infection is receiving cefazolin via IV infusion three times daily. The medication provided is cefazolin 1 g in 250 mL D5W to infuse over 30 minutes. The tubing drop factor is 20 gtt/mL. At what rate (in gtt/min) should the nurse regulate the IV infusion?

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Specializes in Hospice.

You should be able to do number 1 in your head. 200 ml over 4 hours is 200 divided by 4 which gives you 50 ml/hr.

Number 2 set up using DA: ml/hr= 1000ml/1 L x 1 L/30 meq x 1 meq/1 hr = ? (cross off all units you don't need, multiply across then divide.)

Number 3 set up using DA: gtt/min = 20 gtts/1 ml x 250 ml/90 min = ? (cross off what you don't need which is ml, and multiply across and divide)

Same thing with number 4

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I am taking pharmacology this semester and to be able to pass the class you have to pass the med math portion. One of the things that I have seen in some of the problems is sometimes you are given more information than what you actually need to solve the problem. This can cause issues for people sometimes, I think. If you don't feel comfortable with setting up dimensional analysis problems, you might want to check out some YouTube videos. I know that Khan academy has a video on dimensional analysis that does a good job on explaining on how to set up a problem. Also make sure you are comfortable with conversions, going from grams to milligrams to micrograms.

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Specializes in Critical Care, ED, Cath lab, CTPAC,Trauma.

thread moved for best response.

lorirn2b was very nice to you. We ask that students show their work first so that we can see what they are not understanding or which step is throwing them off.

DosageHelp.com - Helping Nursing Students Learn Dosage Calculations

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I agree with Esme12. Why don't you show us what you have done. This will make it easier for us to help you.

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Specializes in Hospice.

I know, I can't help it, Esme12! I just know what a panic math got me in before I got a handle on DA! So I figured I'd show her how to set them up........ Probably didn't help much though.... I had to watch someone do this with me at least ten times to get it.

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Specializes in Critical Care, ED, Cath lab, CTPAC,Trauma.

((HUGS)) LOL That is ok....I like to see where they are messing up. Which step are they aren't seeing. Are the distractors confusing them.

I want them to learn it for good....we use math every day.

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First you have to figure out how to get rid of the "distractors" in the question. Just try and narrow it down to two things. "What do I need?" and "What do I have available?" It makes it so much easier once you get around all those extra bits.

I also suggest getting VERY comfortable with dimensional analysis. It's so helpful and I usually suck at math.

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