IV calculation questions

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I am having trouble with these two problems, can someone be so kind as to explain how I should work these out ? Thank you ahead of time.

50mL @ 70 mins w/ 10gtts/mL

50mL @ 25 mins w/ 20gtts/mL

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Specializes in Cardiology and ER Nursing.

(Ordered amount * Conversion factor of tubing) / Time in minutes to infuse over = Drops per minute

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Specializes in Cardiac, Rehab.

GTT/min=50ml/70mins x 10GTT/1 ml

ML's drop out so you are left with 50/70 x 10 GTT/Min. The math is simple from there.

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i am having trouble with these two problems, can someone be so kind as to explain how i should work these out ? thank you ahead of time.

50ml @ 70 mins w/ 10gtts/ml

50ml @ 25 mins w/ 20gtts/ml

why are you having problems?

do you not understand the formula or does your math come out wrong?

review: you are not using an iv pump that infuses in ml per hour but you are using a drip chamber that infuses in drops/minute.

one of the drip chambers will give you 10 gtts [drops] per 1 ml.

you are going to infuse 50 ml over 70 minutes using the drip chamber that will bive you 10gtts/ml. the answer will be in _________ gtts/min. you can set up the problem as, and i like to reduce the problem as much as i can.

50 ml x 10 gtts = ____ gtts/ml

70 min 1 ml

the second question will infuse the same ml's but will infuse the mls faster (over 25 minutes) and you will be using a a drip chamber that will infuse 20 gtts/ml. the drops in this chamber will be smaller in size than the 10gtts/ml infusion set but there will be more drops per ml (20) than what you would get from the 10gtts/ml infusion set--this explains why the first problem's answer has less drops per min (the drops are larger) and the second problem's answer has far more drops per minute (the drops are smaller).

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Just learned this tonight in my dosage calc class too. :)

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Ok, here is how I would tackle this

first problem

50ml running at 10gtt per ml is a total of 500 drops to be infused (50 x 10 = 500)

500 drops running for 70 minutes (500 divided by 70 = 7.142857142857143)

this is rounded to 7 drops per minute because you can't have a portion of a drop

second problem

50 ml x 20 gtt = 100 total drops to be infused

100 drops / 25 min. = 4 drops per min.

Please let me know if this makes sense or not.

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Specializes in Electrophysiology, Medical-Surgical ICU.

I think charlie T means 40 gtts/min on the 2nd problem (50*20=1000 not 100)

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[quote=charliet;5373621]ok, here is how i would tackle this

first problem

50ml running at 10gtt per ml is a total of 500 drops to be infused (50 x 10 = 500)

500 drops running for 70 minutes (500 divided by 70 = 7.142857142857143)

this is rounded to 7 drops per minute because you can't have a portion of a drop

second problem

50 ml x 20 gtt = 100 total drops to be infused

100 drops / 25 min. = 4 drops per min.

please let me know if this makes sense or not.

questions are:

50ml @ 70 mins w/ 10gtts/ml = 4 gtts/min

50ml @ 25 mins w/ 20gtts/ml = 40 gtts/min

i agree with the first answer but how did you get the second answer

50ml/25min * 20/1ml = 40 gtt/min

oh, i see 50 x 20 = 1000 not 100 - that is the error.

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OOPS, the second answer is 40gtt, sorry for the confusion.

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