IV MATH HELP: unit/hr

GingerSue · Jan 17, 2009

Dose Required x vehicle = X

Dose Available

1200 units x 500 mL = X

25,000 units

24 mL = X

bsugar888 · Jan 18, 2009

This is the way I do it.

ml

--- = 500 ml x 1200 units= 5100

hr 25,000 x 1 hr = 25

units

25/5100= 24 ml/hr

Hope this helps

flightnurse2b, LPN · Jan 18, 2009

Hello.
For the most part I understand IV math (gtt/min, ml/he etc), but I am having a hard time with unit type questions. I have looked throughout medspub and several websites that I normally use. All the help I have found up to this point is that 1mL = 100 units, but I still cant figure out how to solve these type of problems.
Ordered: Heparin 25,000u/500mL to run at 1200u/hr
How many ml/hr will I start pump at?
**** I don't understand how the answer 24mL/hr. Is there a formula for these problems, I am sorry but I am so confused.
Any help is very appreciated.
Thank you.
Missy

you can do it one of two ways, formula wise.

you can either use: dose desired/dose on hand x volume or you can set it up as a ratio....

remember that an IV pump always has to be set in ml per hour. so if you have 25,000 u in 500 ml, 1200 u would be in how many ml's?

the way i would have done this is to solve for X:

25,000 u : 1200 u

_______ = ______

500ml : X ml

600000 = 25000 X

X = 24 ml

MissMelMcRN · Jan 18, 2009

__1,200u__ x 500 ml = 24 ml :up:

25,000u

missa4 · Jan 18, 2009

So I understand that part now and have pracitced it on my homework but after looking futher ahead there are other problems that i am getting hung up on. They are the same concept but different....

A client is to receive Heparin 25,000 u in 500mL of D5W at 7mL/hr. How many units per hour will the pt receive?

*** So my papers say the answers 350u/hr, but I dont know how to going about the set up when it says 7mL/hr?

ANY HELP PLEASE, THANKS!!!!

flightnurse2b, LPN · Jan 18, 2009

So I understand that part now and have pracitced it on my homework but after looking futher ahead there are other problems that i am getting hung up on. They are the same concept but different....
A client is to receive Heparin 25,000 u in 500mL of D5W at 7mL/hr. How many units per hour will the pt receive?
*** So my papers say the answers 350u/hr, but I dont know how to going about the set up when it says 7mL/hr?
ANY HELP PLEASE, THANKS!!!!

same concept. you can't go wrong if you set them up with a ratio. you are still solving for X.

if you have 25,000 unit in 500ml, how many units are in 7 ml?

25,000 u : X ml

______ = ______

500 ml : 7 ml

175000 = 500 X

X = 350 u

missa4 · Jan 18, 2009

Thank you... I was confusing myself trying to set it up!!!!! MUCH HELP!

flightnurse2b, LPN · Jan 18, 2009

Thank you... I was confusing myself trying to set it up!!!!! MUCH HELP!

you are welcome. don't read too much into what the question asks you. pick out the info you need only and plug it in.

when you set up your proportion figure out what the X you are solving for is and then make sure your units match up ex: ml/units = ml/units or units/ml = units/ml.

you'll get it. i recommend getting a math for meds book and just practice. good luck!

BeeBeeRN · Jan 18, 2009

looking for ml/hour

500ml/25,000units x 1,200units/hour = 600,000/25,000 = 24ml/hour

(the two "units" will cancel each other out and you are left with ml/hour)

MissMelMcRN · Jan 18, 2009

How about...

25,000u divided by 500ml = 50u/ml

50u/ml x 7ml/hr = 350u/hr

Does this make any sense? :typing

Daytonite, BSN, RN · Jan 18, 2009

missa4. . .i responded to the other thread that you posted. i think that you are getting hung up on the label "units". if you changed "units" to "mg" the problem wouldn't be any different. milligrams are how a lot of drugs are measured out. a teaspoon is how we measure out sugar. a cup is how we measure out flour. "mg" and "units" are just the ways this stuff is measured out and put into these different iv fluids. sometimes it helps to draw a picture of these things when you are first working with them to help you keep the concept of what you are doing organized in your mind.