New Nursing Student-- IV calculation questions?

[SaltyhairSandyfeet]

Hi Everyone! I am about to start my accelerated nursing program soon, and I'm extremely excited and nervous. I was given a pre-worksheet on dosage calculations to do, and I am slightly overwhelmed because I'm not so great in math. I have gotten all of my questions right, except I am having trouble with one problem, and I was hoping someone could help me with the formula to figuring it out? The questions is regarding an IV infusion that was started at 9AM at 50 drops/minute, and the set delivers 60 drops/mL. After two and a half hours (11:30), how many mL of fluid should have been infused so far?

I'm coming up with 100mL, but I'm not sure if I did my calculations correct. Any advice would be greatly appreciated!

[THELIVINGWORST, ASN, RN]

Dimensional analysis is the best, foolproof way to do these problems. You always need to figure out what you're looking for (i.e. mLs) and set up the problem so that you can cross cancel. That way, at the end you just cross multiply and divide the numerator by the denominator.

1mL x 50gtts x 60 min x 2.5 hr = 125 mL

____ ______ _____

60 gtts 1 min 1 hr

So cross cancel the gtts, min, and hr and only mL is left, now you may multiply (1x50x60x2.5) and (60x1x1) and then divide (7,500/60) equals 125.

[suppaduppaCNA]

Here is what I got:

1. The total time of infusion

2.5 hrs= (60min*2)+30min= 150min

2. The total amount of drops patient received

50gtts/min for 150min= 7500 gtts

3. The amount of mL infused by microdrips

7500gtts/60gtts for every mL = 125mL (gtts cancel out)

The answer is 125mL:)