gtt per ml?

the number of drops per cc of fluid is known as the "drop factor." the three most common drop factors are 15 gtts/cc, 10 gtts/cc, and 60 gtts/cc (aslo know as "micro drip (drop?) tubing.")

the drop factor should be clearly stated on the package of iv tubing. most facilities use either 10 or 15 for the regular tubing, as well as 60 for things that need to be closely regulated (peds, vasoactives, etc).

because the use of iv pumps has become more and more common, nurses arn't having to deal with drop factors nearly as often as they used to; but how to calculate drip rate (how many drops per minute) from an ordered iv rate (such as 60 cc/hr) is a very common test question, and every nurse needs to know how to do it. you never know when the power maya fail and you have to rely on these "old" skills.

BS Nursing Student said:

I thought that there were 15 gtt in one ml. One instructor told me a couple of days ago that it is 60 gtt per ml per Peds. I think that she is wrong. Any thoughts?

micro tubing, which is not as common as it once was, has this little metal stick in the drip chamber. it takes 60 drops to make a ml. where i work, the drip chambers were green. the package was labeled 60gtts/ml.

macro tubings have a white drip chamber where i work and huge drops fall from the drip. they are labled 15gtts/ml bc only 15 of these huge drops are needed to make an ml.

if someone needs nss at 25 ccs an hour....

using a micro, it would come to 25 drops a minute. (always the same #)

using a macro, you divide 25 by 4 and you would get about 6 drops a minute.

now, logic tells you to use the micro drip bc you can set 25 drops a minute better than 6....6 may even cause the line to clot off...it's just too slow.

on the other hand, if the pt is ordered 100 ccs an hour....

using micro, that would be 100 drops a minute (always the # with micro)..which would be hard to manually set!!!!!

but with macro,

you divide 100 by 4 (bc 15 goes into an hour 4 times) and you get 25 drops a minute!

so in this case, the tubing of choice would be macro!

Hey everyone; first time poster and first year (NU100) ADN student - we're actually having our first med calc test this Tuesday coming up. But anyway, both 15 and 60 is correct (to a point)...but for us (and remember we're first semester students and they may be keeping things somewhat simple for us at this point), we're supposed to assume 15 gtt unless they specify 'microdrop'. And when I say that, I'm referring to how they will refer to it on the test - although we've started our initial parenteral medications training, we haven't got into IV infusion yet and I have no idea how the actual packaging will refer to it.

Oops - looks like I've bumped up an old thread:)

it's all good! someone is learning this for the first time every semester, so maybe a bump was a good thing!

critterlover said:

[...]is a very common test question, and every nurse needs to know how to do it. you never know when the power maya fail and you have to rely on these "old" skills.

how true. i did not understand why we had to learn drips. after all, are in the 21st century and use iv infusion machines. that was until one day in my clinical rotation that the floor ran out of iv infusion machines ...i had an abrupt attitude reversal . fortunately, i was in a program that stressed med math, etc. no problem converting. funnything about hands on learning, one can understand the rationale behind the theory.

hi. i was just going thro this article. 1 ml equals 10~15 macrodrops or 60 microdrops. which means 1 macrodrop equals 4 microdrops. this works well only on clear fluids, which means viscosity plays a role.

anyone can mail me at [email protected] and i will try to solve the questions as far as i can.