# new and need help with maths question

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I posted this question in another room...but was suggested I try asking here? I am working on preparing to take hesi exam to enter block 3 advanced entry..and am stumped wit a med math question.Mabey I am studying too much?

anyway,,here it is..

My pt is getting Levophed at 10 mcg /min

The concentration is 2 mgs in 250 ml 0.9%N.S.

How many mls per hour should I set my pts pump to?

I have PILES of notes and have aced all my med math and all of a sudden I am just Baffled.Can anyone help me jump start my brain? Id appreciate it.

thanks

4,106 Posts

Specializes in Cardiac.
I posted this question in another room...but was suggested I try asking here? I am working on preparing to take hesi exam to enter block 3 advanced entry..and am stumped wit a med math question.Mabey I am studying too much?

anyway,,here it is..

My pt is getting Levophed at 10 mcg /min

The concentration is 2 mgs in 250 ml 0.9%N.S.

How many mls per hour should I set my pts pump to?

I have PILES of notes and have aced all my med math and all of a sudden I am just Baffled.Can anyone help me jump start my brain? Id appreciate it.

thanks

I'm not sure what this has to do with open book exams?

Also, the standard dose of Levophed is 4mg/250 mL of D5W (That's just the anal ICU nurse in me).

Standard dose of levo at 10 mcgs/min is 37.5 mL/hr. So for your concentration it's 75ml/hr.

Find the concentration of the med.

2mg/250mL. That's 2000mcg/250ml. When you divide that you get 8mcg/mL.

1mL/8mcg X 10mcg/min X 60min/1hr

Using dimensional analysis, you are left with 75ml/hr.

1 Article; 39,477 Posts

Specializes in Medical and general practice now LTC.

Moved to a thread on it's own as off topic to the one it was in

190 Posts

My pt is getting Levophed at 10 mcg /min

The concentration is 2 mgs in 250 ml 0.9%N.S.

How many mls per hour should I set my pts pump to?

Use dimensional analysis. You can use this for almost anything... learned it in school.

3. From there, use conversions to get rid of units that aren't right (mg to mcg, min to hour, etc).

4. If you do it right, all of the units should cancel out except for the ones you need in the end. If they don't, you did something Wrong!

5. Type all of the numbers on top, putting a "x" (multiply) in between.

6. Hit equal sign

7. Divide answer by all the numbers on the bottom (hit division sign and type numbers in with division signs in between. Hit equal at the end and you should have your answer.

ml = 250ml x 1mg x 10mcg x 60min= 75ml

hr 2mg 1000mcg min 1hr. hr

Hope this helps! :thnkg:

190 Posts

For some reason, it's messing with the alignment of my numbers....

It should look something like this:

250ml/2mg 1mg/1000mcg 10mcg/min 60min/hr =75ml/hr

Just remember: Multiply top numbers and total. Then, divide total by all bottom numbers. The answer you get will be your answer, just add units!

48 Posts

DUHH dimentional analysis.Tats chemistry.I knew I knew this from somewhere.Thank you all so much and I appologize for not sticking with topic.I couldnt find a math nursing room and this one said "general.

But again..I thank you..((hugs))overtired nursing student

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