# Old nurse needs math help!

1. hello! i am re-entering the nursing field and trying to brush up on my math. can anyone help me solve this problem using dimensional analysis? i have been working on it forever!!!!

[color=#0080c0]for the client whose weight is 130 lbs and has dopamine ordered at 8 mcg/kg/min, what rate should the infusion pump be set for a solution of 400 mg dopamine in 250 ml d5w?
[color=#0080c0]
[color=#0080c0]thanks!!!
•

Joined: Oct '08; Posts: 158; Likes: 246
from US
Specialty: 4 year(s) of experience in OR

3. So, first you want to know mcg/min. 130 pounds = 59.09 kg
8 (59.09)=472.73
So, your order is for 472.7mcg/min or 0.473mg/min or 28.3mg/hour (60 minutes)

Then you want to know how many mg are in each ml.
400/250
So, 1.6mg/ml

So now you know there are 1.6mg/ml and 28.3mg/hour

How many ml/hour do you need to get this dose? In other words, how many ml will get you the 28.3mg?

28.2/1.6= 17.7 ml/hr
Last edit by MissIt on Apr 16, '10
4. 8 mcg X 130 lb X 1kg/2.2 lb X 250 ml/400mg X 1mg/1000mcg X 60min/1hr
______
kg/min

=17.7 ml/hr
Last edit by EymieICURN on Apr 16, '10
5. I do not know about dimensional analysis, but I used the good ole formula method and came up with 17.7 ml/hr.
How long have you been away from nursing? I am getting back in nursing as well.
Good luck and feel free to pm me, love to talk with you regarding returning to the field.
6. Thanks everyone! I am returning after about 3 years being away from the bedside. I was overseas in central asia as a humanitarian aid worker and got a bit rusty on my nursing skills It took a while for me to get a job and most hospital recruiters said I was "borderline" for the hospital, and I really didn't want to take a refresher course....although a med math refresher course might be useful!

gtoko- how long have you been out?