ok......we started IV flow rates and the like last week.....and i have a hard time with math.....once i get it and do it often i am comfortable.....til then...this hit and miss with calculations kill me.....i am 45 and way out of touch.......other than math i LOVE school.....
here is a question....perhaps someone can explain it better or in a way i might grasp it......dont laugh....it is probably a very easy question
doc orders xxxxx @ a rate of 40mg/hr. the concentration of med is 600mg per liter of IV fluid. Calculate how many mg/min of the drug the PT is receiving: ALSO calculate what the drip rate is(gtts/min) if an infusion set c a drop factor of 60 gtts/ml is used......
is that c a typo......am i not getting a abreviation? otherwise this is just mumble jumble to me........sad arent i?
thanks all in advance for your help!!
Feb 13, '08
Quote from Daytonite
How many mg/min of the drug is the patient receiving?
40mg/hour (dose patient is receiving) x 1 hour/60 minutes (conversion factor) = 0.666 mg/minute, rounded off to 0.66mg/minute
Calculate the drip rate in gtts/minute for an infusion set with a drop factor of 60 gtts/mL
0.66mg/minute (dose desired) x 60 gtts/mL (drop factor of IV tubing) x 1 liter/600 mg (dose on hand) x 1000 mg/1 liter (conversion factor) = 66 gtts/minute (drip rate)
When I did this according to my old calc book from first semester (because the problem bothered me, so I drug out the old book!), I got 40 gtts/min.
According to the book, Essential Drug Dosage Calculations
-first determine the number of mLs/min to get the prescribed dose, which here is 40 mgs/hr out of 600mgs/liter. I did it the long way to check myself, and got the 0.67 (well, actually 0.666666.....).
The book now says to multiply the mLs/minute by the drip factor:
0.67(60) = 40.2 gtt/minute to give you 40 mg/hr.
All of the problems in the book are done this way, this is how we did them in school, and I never got a math problem wrong - either in didactic or in clinical. I also never killed anyone
or had any med errors in clinical. So if I'm doing something wrong now, please show me - and that's a sincere request. Sometimes this stuff confuses me because I over-think it...and it is late besides!
ETA: OH YES, I AM A TOOL - I left out half the calculation - remind me not to do math this late...
Last edit by carolinapooh on Feb 13, '08
: Reason: self-correction