Need help with a dosage problem?

Well I got an answer. However, in order for us to help you, we would need you to tell us first which method you use in solving Med math problems; desired over have, etc.

Secondly, it would probably be better if you were to explain to us what you did to solve this problem, and then what you got for an answer. That way it would be easier for people on the forum to help you out. If we were to just tell you the answer and/or what we got for an answer that's not really helping anyone out much.

40ml?

40ml?

No, 40 mL is not correct.

As with the OP, how did you get this answer?

You might want to check your first sentence... Im coming up with that answer too.

[...]

Thank you, I stand corrected. I obviously stopped reading after the 4 gram bolus.

Well I took 50g = 50,000mg so 50mg/ml Then I thought how many mg are we looking to solve for 2000mg. if it is 50mg/ml then 40ml=2,000mg. 50*40=2000. So 40ml/hr.

This is how I got my answer.

Rose_Queen said:

Even us experienced nurses sometimes fall for the extraneous information.

Yes, we do. This emphasizes the need for independent second checks.

That's one way to do it, but does include extra steps. The formula desired (2g)/ have (50g) x volume (1000mL) would have given you the same answer in fewer steps. D/H x V was always an acceptable formula in all of my nursing classes.

Thank you for this info! Can I use this equation when I have drop factors or mg/kg conversions?

I am applying gir nursing school September first have I have been just teaching myself as I go.

Any help would be great.

Thank you

Noctor_Durse said:

Thank you for this info! Can I use this equation when I have drop factors or mg/kg conversions?

For drops/minute, you can use the following formula:

• (total volume to infuse [mL] / total time to infuse [minute]) x drop factor

For me, it is easier if I determine mL/hour first, and then calculate drops per minute using the following:

• (mL/hour / 60) x drop factor

It depends on how specific they want your answer. If they don't want to count, or subtract that first 4g, then you can technically just base your answer off of the entire 50g in 1,000 mL. However, if they are giving you the previous information, the 4g, looking for you to subtract that from your would-be answer, then you need to make sure you calculate your answer with that in mind.

So in that case you want to find out much medication is in your bag per mL. In our case here just divide your total 1,000 mL by how much mag you have, which is 50g. This comes out to 20mL/1g (mag). Now they said previously that you were to administer 4g of mag. The 15 minutes of time is not really relevant in this case, unless they were too otherwise state that it was important, because after the 15 minutes you will just be administering per hour.

So we take your 4g and multiply that by your 20 mL (20mL/1g that we just got). This comes out to 80mL. Subtract this 80mL from your total 1,000mL of solution, this leaves us with 920mL.

Now your problem starts. Keep in mind that you are solving for mL's. mL's per hour, but mL's nonetheless. Your problem is now: you need to administer 2g of mag per hour. You have on hand: 46g of mag in 920mL solution.

Your equation = 920mL of solution divided by how much medication you have left on hand, which is 46g, times the amount of medication per hour you want, which is 2g. So your equation will look like:

920mL / 46g X 2g = 40mL per hour.

For drop factors you would use volume/time to infuse (minutes or hours) x drop factor.

Most problems can be solved using very similar equations. I would definitely suggest once you get into nursing school, or even before, if you can find a med math tutor, to definitely utilize that resource. Many nursing programs nowadays have Med math tutors. Good luck my friend. I hope that helped somewhat, and I hope it wasn't too drawn out. I was just trying to go step by step. That's how I learn anyways, and just was hoping that may help.