How would you solve this?

morte, LPN, LVN · Jan 15, 2009

the gtt ratio varies from IV set to IV set.....the question should have given you the ratio being used in that question....what is the anser, per the book?

Daytonite, BSN, RN · Jan 15, 2009

You cannot perform any calculations for this problem without being given what the drop factor is for the IV tubing is that is being used. That information is missing from the problem.

E.R. Rookie · Jan 15, 2009

The answer is 13 mcg and thats all the info it gave in the question.

Another student sent about 20 problems in an email from a clinical calculations book. So far I have found the problems to be very confusing!

morte, LPN, LVN · Jan 15, 2009

The answer is 13 mcg and thats all the info it gave in the question.
Another student sent about 20 problems in an email from a clinical calculations book. So far I have found the problems to be very confusing!

so they are using a micro gtt, which is 60 gtt/ml.......but as we have already said there is no way for you to get an answer without the gtt factor......if the questions were typed, i suspect a transcription error, if they were scanned in and emailed then it is an error ine book....good luck

Daytonite, BSN, RN · Jan 15, 2009

a nitroglycerin solution of 25 mcg/ml is infusing at 30 gtt/min. calculate the mcg/min the patient is receiving.

with microdrop (pediatric) tubing which has a drop factor of 60 gtts/ml:

25 mcg/ml

(dose on hand)

x 30 gtts/minutes

(dose being given) x ml/60 gtts (drop factor of iv tubing being used)

= 12.5 mcg/minute

, rounded up to

13 mcg/minute

. the reason the answer is rounded is because none of the figures going into the calculation are expressed as decimals, but as whole numbers, so the answer should also be expressed as a whole number as well.

my understanding is 15 gtt = 1 ml

this is an equivalency. 15gtts = 1 ml is a measurement, a concept. it is based on the size of a drop in the metric system. iv tubings are manufactured allow different drop sizes to come through the drip chambers. a drop factor of an iv tubing is a real world application of the physics principle of gravity that utilizes the surface tension characteristic of liquids to form droplets of various sizes.

drop factors

drop factors are the number of drops that equal 1 ml. each iv administration set has a drop factor that has been accurately determined by the manufacturer and they are manufacturer specific. flow rates must be based on these drop factors. manufacturers will tell you that their iv tubings deliver from 10 to 60 drops/ml. when in doubt read the information on the package that the iv tubing comes in. here is a list of the many different drop sizes utilized in iv tubings:

10 gtts/ml (macrodrip tubing)
12 gtts/ml (macrodrip tubing)
15 gtts/ml (macrodrip tubing - commonly referred to as standard sets)
20 gtts/ml (macrodrip tubing)
50 gtts/ml
60 gtts/ml (commonly called microdrip, or pediatric, tubing)

the size of drops is not a factor in the delivery of fluid when a pump is used since pumps measure fluid delivery by the amount of fluid that is displaced or movement of fluid through electronic sensors. when in doubt read the information on the package that the iv tubing comes in or the pump instruction manual.

E.R. Rookie · Jan 16, 2009

oh my goodness than you so much! I appreciate it!

Daytonite, BSN, RN · Jan 16, 2009

It helps if you have the opportunity and time to actually sit down with these tubings, some IV fluid and play around with them and watch and observe the drops and some drip rates and infusions and how all this stuff works. Trying to fathom it all from some problems on a piece of paper is difficult. Seeing it in action makes a whole lot more sense. There is a place for those 15 gtts per mL, just not with this particular kind of problem.

morte, LPN, LVN · Jan 16, 2009

It helps if you have the opportunity and time to actually sit down with these tubings, some IV fluid and play around with them and watch and observe the drops and some drip rates and infusions and how all this stuff works. Trying to fathom it all from some problems on a piece of paper is difficult. Seeing it in action makes a whole lot more sense. There is a place for those 15 gtts per mL, just not with this particular kind of problem.

bingo!!! i have only seen the 10/15/60.... hands on is the way to go