IV math question..

[heartnursing]

Hello Allnurses

Im practicing med math and I cant figure out this type of calculation...

Can anyone help me with these?

Thanks!

Medication order: Cardizem 10 mg/h. Available: 125 mg/100 mL D5W solution. Calculate mL/h flow rate.

medication order: Heparin 2500 u/hr. Available: heparin 20 000 units in 250 mL D5W. At what rate will you set your pump?

[anurseatlast]

You are more likely to get responses if you tell us what you think. What do you already know about figuring out IV meds? From other examples you have done, what are the steps to figuring out the rate?

[heartnursing]

You are more likely to get responses if you tell us what you think. What do you already know about figuring out IV meds? From other examples you have done, what are the steps to figuring out the rate?

I can do gtt/min and ml/hr

but this type of question im not too sure what to find first...

Medication order: Cardizem 10 mg/h. Available: 125 mg/100 mL D5W solution. Calculate mL/h flow rate.

this is what I had...

10mg/125mg x100ml

I ended up getting 8 but im not sure 8 of what lol

[Black Jade, BSN, RN]

Try this formula: Desired/Hand x Volume = Amount

[backinwonderland]

You're doing it correctly. Use the formula Desired(10)/On hand(125) X Volume(100) = Amount(8)

It was asking you for ml/h (according to what you wrote) so you got the correct answer with 8ml/h. Looks to me like you don't need the extra help:)

[heartnursing]

THANKS so much! :)

[Mandychelle79, ASN, RN]

I can do gtt/min and ml/hr

but this type of question im not too sure what to find first...

Medication order: Cardizem 10 mg/h. Available: 125 mg/100 mL D5W solution. Calculate mL/h flow rate.

this is what I had...

10mg/125mg x100ml

I ended up getting 8 but im not sure 8 of what lol

If you use dimensional analysis you will always know what your units are:

ml/hr = 10mg/hr X 100 mL/125 mg. The mg cancel out leaving you with mL/hr. If all the units cancel out you have the problem set up wrong ( speaking from experience on that one)

[edgarandersonrn]

Everyone does it differently. I prefer to figure how many mg per mL (mg/ml) and then divide the desire by that answer.

125/100=1.25mg/mL

10/1.25=8ml/hr

Dimensional analysis makes me want zofran.

20,000/250=80u/mL

2,500/80=31.25ml/hr

I find this easier.

[Mandychelle79, ASN, RN]

Everyone does it differently. I prefer to figure how many mg per mL (mg/ml) and then divide the desire by that answer.

125/100=1.25mg/mL

10/1.25=8ml/hr

Dimensional analysis makes me want zofran.

20,000/250=80u/mL

2,500/80=31.25ml/hr

I find this easier.

Yeah, everyone does it differently. I would much prefer to set it up algebraically but was required to use dimensional analysis.

[ObtundedRN, BSN, RN]

Its funny, in all of my chemistry classes I always used dimensional analysis, but in nursing I always preferred Dose/Have X Volume.

[penny112]

Always break it down to simple terms first. You have 125mg in 100mL... So how many mg do you have per mL? 1.25mg/mL. Now you want 10mg/hr? So 1.25 goes into 10 8 times. mg cancels out so you are left with 8mL/hr.