Question 22931
I'm not completely sure about this one, but I'll give it a shot!  (Was that a pun??)


5 mcg/kg/min would imply that we need to multiply by the number of kg of the patient, and then multiply by 60 since the question asks for an amount per hour.  The patient weighs 220 lb, which if I recall correctly would be 100 kg.


5 mcg/kg/min*100 kg*60 min/hr = 30,000 mcg/hr.

  
In metric system you can convert to the larger units of mg, by moving the decimal three places to the left giving 30 mg/hour.


Now, I'd set up a ratio of 

{{{(800 mg)/(500 ml) = (30 mg)/(x ml)}}}


This can be simplified to {{{8/5=30/x}}}


Since {{{a/b=c/d}}} means that {{{ad=bc}}}, it follows that 
  {{{8/5=30/x}}} means that {{{8x=5*30}}} and {{{x = 150/8 = 18.75}}} ml/hr.


Most math teachers, including ME, don't do much with this.  I did try to do a lesson on my website on METRIC SYSTEM and DOSAGES.  Probably nobody knows about it, but it's there if you care to take a look at it.  


Go to my website by clicking on my tutor name "rapaljer" anywhere on algebra.com.  Then look for a page in the second column called "Tech Prep", and go to "Metric System".  Buried way down in that page in which I tried to show how simple the Metric System is, there is a section on Medical Dosages that might or might not be helpful.  Let me know what you think!


R^2 at SCC