Med Calc Help!!

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Hi, I am a Junior BSN student looking for assistance in some med calc questions for a test coming up in a few months. I have the answers, however there is no explanation of how one gets the answers. Hopefully someone will be able to walk me through it so I will be able to do it and others similar on my own. Here are the 4 questions below.

1) An IV solutions contains 80 mEq of KCl in 1 L of solution. When 800 mL of solution remains to be given, the patient will have received how much KCl? ____ (The answer it says is 16, but I do not know how to figure it out)

2) A 50 mL bag of IV solution contains 1.5 millions units of ampicillin and is to be infused over 20 minutes. The IV tubing drop factor is 15/gtt/ML When the IV has infused at the correct rate for 12 minutes, the patient will have received how much ampicillin? _____ (The answer is 900,000, again I cant get to this answer)

3) An IV solution contains 2 million units of ampicillin in 50 mL. When 30 mL of the IV solution has infused, the patient will have received how much ampicillin? ___ (the answer is 1.2 million)

4) An IV solution of 1 L D5W contains 40 mEq KCl. When 700 mL of IV solution remains to be given, the patient will have recieved how much KCl? ____ (the answer is 12 mEq)

Any information would be greatly appreciated. Again, I have the answers and is looking for more of a guide on to how the answers were gotten so that I am able to perform these questions myself, and others like it.

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Specializes in OR, Nursing Professional Development.

Start by walking us through what you've done to start the problems. We are happy to help, but we want you to be able to do these yourself. Think about what the question is asking you even though it isn't explicitly stated. What do you need to do as your first step?

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So I have figured out 3 of the 4 problems. Number 2 has been quite difficult and I am still looking for help with this.

2) A 50 mL bag of IV solution contains 1.5 millions units of ampicillin and is to be infused over 20 minutes. The IV tubing drop factor is 15/gtt/ML When the IV has infused at the correct rate for 12 minutes, the patient will have received how much ampicillin? _____ (The answer is 900,000, again I cant get to this answer)

So the question is asking me, after 12 minutes of running (out of 20 that it is being infused over) how much ampicillin has the pt received? I honestly have no clue where to begin. I initially thought that if I divided the 50 mL bag by the 1.5mil units of ampicillin then times it by the 20 minutes I would get my answer. But that was not correct at all.

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Those are really simple problems dude. How are you unable to figure them out? I will do 1 for you.

1. 80/1000= x/800. Multiply 800 times 80. Then divide by 1000. You get 64. Subtract 80-64=16.

Easy peasy.

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Specializes in OR, Nursing Professional Development.
So I have figured out 3 of the 4 problems. Number 2 has been quite difficult and I am still looking for help with this.

2) A 50 mL bag of IV solution contains 1.5 millions units of ampicillin and is to be infused over 20 minutes. The IV tubing drop factor is 15/gtt/ML When the IV has infused at the correct rate for 12 minutes, the patient will have received how much ampicillin? _____ (The answer is 900,000, again I cant get to this answer)

So the question is asking me, after 12 minutes of running (out of 20 that it is being infused over) how much ampicillin has the pt received? I honestly have no clue where to begin. I initially thought that if I divided the 50 mL bag by the 1.5mil units of ampicillin then times it by the 20 minutes I would get my answer. But that was not correct at all.

1. What is your rate?

2. After 12 min, how much solution has infused?

3. In that amount, how many units of ampicillin?

Nursing math is not difficult- it's fairly simple algebra. You need to be able to understand how to read the question and what it is the X you're solving for stands for.

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Specializes in OR, Nursing Professional Development.
Those are really simple problems dude. How are you unable to figure them out? I will do 1 for you.

1. 80/1000= x/800. Multiply 800 times 80. Then divide by 1000. You get 64. Subtract 80-64=16.

Easy peasy.

Providing the answer does not teach the asker how to solve it.

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Specializes in OR, Nursing Professional Development.

Another thought: you also need to be able to pick out the pertinent information in each problem and ignore the unnecessary information. In that question you're still struggling with, there is a piece of information that is 100% irrelevant. Are you able to pick that piece out?

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2. This is how I solved it.

50/20=2.5

2.5 times 12=30

So 50/1,500,000= 30/x.

Mulitply 30 times 1,500,000.

Divide by 50. There you go, you get your answer. 900,000. Youre welcome.

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If it was in fact that simple, I would not have asked. Thank you but not helpful.

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Specializes in Critical Care, ED, Cath lab, CTPAC,Trauma.
If it was in fact that simple, I would not have asked. Thank you but not helpful.

Welcome!

We are happy to help but we ask ALL students show their work first so that we can best help you find where you are going wrong. As a junior in a BSN program....you should have the skills in place to at least tell us your thought process.

DosageHelp.com - Helping Nursing Students Learn Dosage Calculations

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Thank you so much for your assistance. That was what was throwing me off. The 50 mL bag had nothing to do with what they were asking. After taking that out I was able to figure out the question. Thank you for the reminder to always just figure out what they are asking and getting rid of what is not pertinent to the problem!

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Specializes in OR, Nursing Professional Development.
Thank you so much for your assistance. That was what was throwing me off. The 50 mL bag had nothing to do with what they were asking. After taking that out I was able to figure out the question. Thank you for the reminder to always just figure out what they are asking and getting rid of what is not pertinent to the problem!

Actually, the 50mL bag is very important. That tells you the total volume being infused over 20 minutes. The part you don't need is the drip rate factor of the IV tubing.

Step 1: Figure out concentration of ampicillin per mL.

Step 2: Figure out how much fluid infuses in 12 minutes.

Step 3: Figure out how many units of ampicillin was in that volume.

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