MED calculation question

Nursing Students Student Assist

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Okay so I took a test yesterday and one of the questions was a med question I don't know if it was a typo or if I just don't get it.

Question:

the dr. ordered 7mL/kg/hr for a 6 month old infant that weighs 22 lbs. how many mg should you infuse per hour

Okay my problem is how do you get the correct mg when they don't tell you how many mg there are per mL, are you just suppose to assume that it is a one to one ratio. How do I know that there is not 40mg per mL or 1mg per mL. Maybe I am just confused I would love anyones opionion on this. Thank you

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Specializes in ICU/ER.

I think it was a typo--unless I am wrong I have never seen a ml/kg/dose question.

only mg/kg/dose.

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Specializes in neuro, ICU/CCU, tropical medicine.

If it's not a typo it's a bad order that needs to be clarified.

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Specializes in Day program consultant DD/MR.
If it's not a typo it's a bad order that needs to be clarified.

The Dr. would be getting a call on that one........

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Specializes in Med-Surg, ER.
I think it was a typo--unless I am wrong I have never seen a ml/kg/dose question.

only mg/kg/dose.

One often gets a ml/kg/hr order for maintenance fluids in children and infants. 7ml/kg/hr seems a little high for a maintenance rate for a 10kg child, but nursing school questions are sometimes not based on reality. In the OP post, the "how many mg should you infuse per hour" was probably the typo, and should have been "ml".

Don't hesitate to ask a nursing instructor for clarification on a question like this. Most will note the mistake and point it out to the whole class.

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Specializes in Case mgmt., rehab, (CRRN), LTC & psych.

Moved to the Nursing Student Assistance forums.

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Specializes in med/surg, telemetry, IV therapy, mgmt.
the dr. ordered 7mL/kg/hr for a 6 month old infant that weighs 22 lbs. how many mg should you infuse per hour?

The "mL" is probably a typo and should be "mg". I would have gone to the instructor during the test and questioned her about the problem.

7 mg/1 kg
(dose desired)
x 22 lb/1 hour
(weight of child/desired time)
x 1 kg/2.2 lb
(conversion factor)
=
70mg/hour
(dose to give)

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I did write down the answer of 70 but when I asked the instructor if it was a typo she told me I wasn't thinking about it hard enough and that it could be done.

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Specializes in Medical-Surgical/Oncology.

Knowing how many mL or mg per dose is not important is this calculation. That is just simply letting you know the dosage per mL or mg. That used to confuse me all the time. Just multiply 22 pounds by 2.2 which should equal 10kg. The order is 7mL/kg/hr so the equation is 7mL/10kg/hr which equals 70mL/hr.

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Specializes in Med-Surg, ER.
Knowing how many mL or mg per dose is not important is this calculation. That is just simply letting you know the dosage per mL or mg. That used to confuse me all the time. Just multiply 22 pounds by 2.2 which should equal 10kg. The order is 7mL/kg/hr so the equation is 7mL/10kg/hr which equals 70mL/hr.

Great, now how do you answer the rest of the question?

"how many mg should you infuse per hour"

There's a typo somewhere - as the OP stated, in order to fully answer the question as written, you need a conversion factor for ml to mg.

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Specializes in Gerontological, cardiac, med-surg, peds.

I agree - typo or some sort of error. Left out mg to ml conversion information.

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