dimensional anaylsis & IV dosing

Daytonite, BSN, RN · Feb 8, 2008

I have tried to work this problem out a number of ways and cannot come up with anything. Nothing makes sense. Are you sure your numbers are correctly stated? You might want to go to the instructor and have them explain this problem to you again. Insulin in a bag of IV fluid isn't normally stated as "50kg/500mL", but at mg/mL or units/mL. However, a patient's weight is often involved in these kinds of problems where "kg" are given. Are you sure you aren't missing the patient's weight in doing the math for this problem?

reidesert · Feb 8, 2008

I am totally confused. That is all the information she gave. She actually first came up with 500 units of insulin before break and then after she said that it was too much and she made an error. When I go back to class, I'll ask her how she did the problem. Thanks daytonite for trying to make sense of it.

flower75 · Feb 10, 2008

I do all my math using the dimensional analysis. It got me through 1st semester just great. I am really not understanding the IV dosing questions and how to set this problems up since the text book and my teacher use ratios. Is there a way to set up these problems using dimensional analysis?
For example, in lecture our teacher asked us to work out this problem:
0.1 unit/kg/hr in PB
50 kg/500mL NS
25 mL/hr
How many units of insulin would you give?
all I can say is huh? scratching my head while looking just confused
please Help!
The answer she came up with was 50 units of insulin at 5 ml/hr

I use DA for all my dosage calculations. It seems like the info she gave is wrong. When we are given a problem we usually have the order from the physician such as the 0.1 unit/kg/hr. the pt's weight in pounds or kg as a given. Also, we are given the stock solution for a bolus or infusion such as 400mg Dopamine in 250ml D5W. they tell us the drip factor such as 20gtt/mL for the tubing and if they don't give us a drip factor we assume it is microdrip tubing. then we figure out how many gtt/min or ml/hr, whatever they are asking for on that question. So it seems like a lot of data is missing from the questions and that some of it was given to you incorrectly. Hopefully they can get it figured out. If you need help, I would be glad to help you. DA is the best :nuke: