Let's use an example similar to the one on the last page :
The patient is prescribed:
720ml of mixture over 6 hours
720mL ÷ 6 Hrs = 120mL/Hr
determine how much per Minute.
120mL/Hr ÷ 60(min/Hr) = 2mL/min
We arrived at 2mL/min
The Infusion set device delivers 10 gtt/ml,
Now, simply take the amount of ml/min and multiply it by the gtt/ml.
2ml/min x 10gtt/ml = 20gtt/min
This example seemed very easy, right? Well, it really is just that easy. The only things that makes it more complicated are fractions, decimals and rounding up to the nearest drop. As long as you keep gtt/ml and gtt/min straight the rest is just math. Would you rather watch a video? Here's one - Video Tutorial
Question from Angel on Yahoo! Answers
The patients weight is irrelevant. The 250ml IV is just saline and used as a vehicle to carry the active drug into the patient's body. Angel is in pharmacy tech school and I know she knows some math. So....
First you need to convert your mg's to mcg's.
Next, using proportions math you can determine how many mL's are needed to deliver 5mcg's.
Here is how it will look:
You now know that 0.05 ml contains 5mcg
The patient needs 5mcg/min, so they need 0.05 ml/min
0.05 ml x 60 min = 3ml/Hour
The Answer is 3ml/Hour
By Zita Schmitt, CPhT
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IV Infusion flow rate example