# calling all math wizzes!!!!!!

1. 20,000 units of Heparin are in 500 ml of D5W. The patient is to receive 24,000 units per day. What are the rate and volume settings for the pump?
Thanks!!

Joined: Sep '06; Posts: 12
nursing student

3. OK, I don't start NS until Jan, but I'm good in math, so I'll tell you what I think I know!!!

You have 20,000 units in 500 mL
you desire 24,000 units

Desired/have=24000/20000=1.2*500=600mL total to be given per day (volume)

total mL ordered/total h ordered= mL/hr
600/24 = 25mL/hr

if you drops per minute you'll need to know the drop factor for the tubing or whatever supplies you're using

I hope this helps you some
4. assume that all iv pumps are set up to deliver ml's per hour unless your problem states otherwise. by dimensional analysis, or factor label method, you want the problem to end with the labels of mls per hour on the final answer. here is how you set that up to factor out all the labels and include the conversion factor that you need to get to the final answer:
24,000 units / 1 day (dose desired) x 500 ml / 20,000 units (dose on hand) x 1 day / 24 hours (conversion factor) = 12,000,000 ml / 480,000 hr (after factoring out labels in numerators and denominators and doing the math) = 25 ml / hour (final answer).
the set up of the above was derived from using the formula of dose desired divided by the dose on hand. doing that gives you a complex fraction (a fraction in the numerator and a fraction in the denominator). remember that when you simplify a complex fraction, both the numerator and the denominator of the fraction must be multiplied by the reciprocal of the fraction in the denominator in order to make the denominator = to the number 1. that is how the second term of the equation above came to be 500 ml / 20,000 units.

oops! let me finish the answer. the question asks: what are the rate and volume settings for the pump? the rate will be 25 mls/hr. the volume you will program into the pump will be 500ml because that is the volume of the iv bag you are hanging.
Last edit by Daytonite on Nov 6, '06
5. Yay, I got the right answer, I don't even have a dosage calculations book, just going by stuuf I've picked up on this site Go Me!!!