IV Rate Problems!

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I cannot figure out how to complete this medication calculation problem! How do you complete these types of problems? I am in nursing school and have a quiz over these types of problems and want to know how to do these. Any advice is greatly appreciated!

Problem:

You are taking care of a 12 year old with a skin infection following a bicycle accident. You have orders to give Ceftriaxone IV 1,000mg every 12 hours. When in the medication room you note that Ceftriaxone 1,000mg has been dispensed by pharmacy and diluted in a 125mL bag. What do you need to set your rate on the IV pump to run this antibiotic over 30 minutes?

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It's going to be 4.16ml/min.

I got this because I just divided 125ml/30min.

If you take 4.16ml every minute for 30 minutes it comes to 125 ml total.

If I'm wrong please someone stop me now and clarify. Thank you

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Why don't you show what you have done so far?

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It's going to be 4.16ml/min.

I got this because I just divided 125ml/30min.

If you take 4.16ml every minute for 30 minutes it comes to 125 ml total.

If I'm wrong please someone stop me now and clarify. Thank you

In my experience, per minute is typically used when calculating drops per minute. When using an IV pump, most that I'm familiar with allow you to enter the volume to infuse and either the rate in mL/hour, or the infusion time and the pump calculates the infusion rate.

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Specializes in NICU.
It's going to be 4.16ml/min.

I got this because I just divided 125ml/30min.

If you take 4.16ml every minute for 30 minutes it comes to 125 ml total.

If I'm wrong please someone stop me now and clarify. Thank you

It is an IV pump, so it's mL/ hr.

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OK so if we need to give 125ml over 30 min we can set the pump for 250ml/hr and let it run for 30 minutes.

Is this thinking too abstract or will it work?

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OK so if we need to give 125ml over 30 min we can set the pump for 250ml/hr and let it run for 30 minutes.

Is this thinking too abstract or will it work?

No, not too abstract at all. However, as the OP came here asking for help, you providing an answer is not useful, as he or she still doesn't know how the problem should be setup.

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I am learning too! I am just continuing the conversation and trying to facilitate the discussion. If he/she reads this they may learn something. For all we know they may not ever come back on this website (I hope they do and i hope things are more clear for them) so at least there is a discussion and the question did not go unanswered.

P.s. I learned something too, so the discussion was not waisted. Thank you for all your replies.

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LISTEN.....remember in chemistry when you followed the labels? This is totally applicable when doing nursing calculation!!!!! And it is tons easier and makes a hell of a lot more sense to me than the equation they try to teach you.

In chemistry you flip the equations with the labels to cancel them out and leave the one you need. I used this method in nursing school and aced all the nursing math!!

In this case they are trying to confuse you with extra information. All you need to look at is the fact that the correct medication dose is supplied in a 125 mL bag. You want to end up with mL/hr

125 mL -----60 min

_______ X _______ =

30 min ------1 hour

you cancel out the minutes which will leave you with mL per hour -- 125 x 60 divided by 30 = 250 mL/hr

This did not necessarily need to use this equation method BUT if you get in the habit and solve the problem following the labels I guarantee this will make the calculations so easy. You cannot get the wrong answer when you follow the labels.

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Thank you all so much for your help.

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Specializes in Emergency.

Lets make it simpler. You know if it's to be infused in an hour, it would be 125mL because 125mL/hr = 125mL/hr. But, this wants you to infuse it in HALF the time (30 minutes). Wouldn't you double the infusion rate? ;-)

edit: If this still confuses you, know that rate always means mL/hr. How many minutes are in an hour? 60 minutes. But this wants you to infuse in 30 minutes. What are you going to do to calculate to 60 minutes?

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These questions try to give you more information than you need to confuse you. Concentrate on the fact that the antibiotic was put in a 125 ml bag. The 1000 mg doesn't matter anymore at this point. When you're a nurse you will see many different doses in the same exact bag. You'll see 2 grams in 100 ml of NS or 1 gram in 100 ml of NS, etc.

But now, the question is asking you how fast the rate would be. The bag is 125 ml so you know it will go in over 1 hour if you set it at 125 ml/hr. You want the med to go in twice as fast so you will double the rate to 250 ml/hr.

Anytime you see a question saying the med has been diluted in "a ____ ml bag" go with that and not the mgs anymore!

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