Published Sep 9, 2012
LCinTraining
308 Posts
I've done this problem ten different ways and keep coming up with 5.5 drops/min, but the answer is 17 gtts/min when I check my answer with the answer code. Any help is appreciated...The order is for D5W at 100 mL/hr. The drop factor is 10 gtts/mL. Calculate the flow rate in drops/minute.I've tried various dimensional analysis set ups, but 5.5 is what I get. I'm starting to think I'm missing a conversion factor that I can't seem to remember or something.
morte, LPN, LVN
7,015 Posts
17 is correct, what are YOU doing to get 5.5? show us your work, and we can better help.
iluvivt, BSN, RN
2,774 Posts
Try this formula.......volume to be infused X the drip factor
-------------------------------------------------
time in min
so get your top value and divide it by the time in min
here is a fast way to get the answer for tests ..divide the cc per hr by either 6 (drip factor of 10) 5 (for a drip factor of 12).....4 (for a drip factor of 15) and 3 (for a drip factor of 20)..... so in your case 100 divided by 6 is egual to 16.66 and round it up to 17
So now work it out both ways and practice
AZMOMO2
1,194 Posts
10(drip factor) X 100(ml) / 60 (minutes in an hour) = 16.66 = 17 gtts/min
Let me rewrite it and get back to you after my nap. I have to work a 12 overnight so it's nap time. I erased my work so now I don't remember, but I'll rework it before looking at the other suggestions so you can see what I'm doing.
Esme12, ASN, BSN, RN
20,908 Posts
Formula:
[TABLE=class: formula]
[TR]
[TD]
[TABLE=class: fraction]
[TD=class: numerator]Volume (mL)
[/TD]
[/TR]
[TD=class: denominator]Time (min)
[/TABLE]
[TD] x Drop Factor (gtts/mL) = Y (Flow Rate in gtts/min)
Example: Calculate the IV flow rate for 1200 mLof NS to be infused in 6 hours. The infusion set is calibrated for a drop factor of 15 gtts/mL.[TABLE=class: example]
Convert 6 hours to minutes.
[TABLE=class: example]
[TD=class: numerator]1200 mL
[TD=class: denominator]360 min
[TD] x 15 gtts/mL = 50 gtts/min
Example: Calculate the IV flow rate for 200 mLof 0.9% NaCl IV over 120 minutes. Infusion set has drop factor of 20 gtts/mL.[TABLE=class: example]
[TD=class: numerator]200 mL
[TD=class: denominator]120 min
[TD] x 20 gtts/mL = 33 gtts/min
Go here for more help....it's a great site. This website provides a dosage calculations tutorial, complete with explanations and examples, to help nursing students prepare for a medication exam.
http://www.dosagehelp.com/
metal_m0nk, BSN, RN
920 Posts
16.66666666666666666666666666666666666666666666666666 is what I came up with.
Pretty easy.
Since you're looking for a per minute rate and the order is per hour, first find how many mL are to be administered per minute.
100ml/hr divided by 60 minutes = 1.66666666666666666mL/min
Then multiply your drip factor (drops/mL) by the number of mL/min.
(10gtt/mL) x (1.66666666666mL/min) = 16.66666666666666666
The mL's cancel out and you're left with gtt/min.
I figured out what I was doing wrong. I kep trying to convert gtts to actual drops and was using an example of 20 drops/mL that was given in lecture.Gtts IS the drop. I got it now. Thanks!