Math- 1:1000 calculations

Hello-

I've recently accepted a new job in a new hospital. In order to give medications, I have to complete a medication quiz. I'm having trouble with a question similar to this:

How many milligrams of Adrenaline are there in 2 mls of 1:1000 solution?

I've been working it out like this:

1 part adrenaline=1000 parts solution

1g/1000 mls

1000mg per 1000 ml solution

1 mg/ml x 2 mls = 2 mg

Am I on the right track? I've been using the following website for guidance, but could certainly use more help/guidance to wrap my head around these! http://www.nda.ox.ac.uk/wfsa/html/u13/u1306_01.htm

Thanks!

Edited Oct 17, 2010 by jbee

[nurse2033, MSN, RN]

You have the right answer. It doesn't matter how you solve the problem as long as you get it right. So solve this one: you put 1mg epi in 250ml normal saline, what is the concentration?......

To solve it start here- 1mg/250ml then multiply x 4/4 (to bring the volume up to a multiple of 10) which gives you 4mg/1000ml, now to find how much in 1ml-divide both by 1000 which gives .004mg/ml or 4micrograms/ml. Since the dose for an epi drip is 1-10ug/min that means you give a vol of 0.25ml-2.5ml/min (15-150ml/hr or 15-150 drops per min in a microdrip set). Probably more than you need to know but always good to review. Good luck.

[jbee]

Thank you for your help (and for the extra practice question).

Remember it's all metric. 1:1,000 is 1 gram in 1,000 ml or 1 mg per ml.