Medication Administration Query

MunoRN, RN · May 18, 2015

I've never seen a pump that is programmed using "drops/min", are you sure that's what you meant?

dudette10, MSN, RN · May 18, 2015

I cannot figure out the answer to the following question - every time I try, I keep getting different answers - please help me solve it/work it out.
I have to administer 140mg IV Lasix in 50 mL. Knowing that I can infuse a maximum of only 4mg/min a) how should I program the pump (drops/min) and b) how long will the drug infuse over?

Interesting! I learned something today with your question. Thanks! High-dose IV therapy for Lasix is max 4 mg/min as compared to IVP at max 40 mg/min. We don't do Lasix drips on the floors I work on.

If the question is indeed drops per minute (I question that too), then you need to know the drips/ml for your tubing. That's not in the question you posed, so you can't calculate without that information.

kenyon · May 18, 2015

the drops/min could be inaccurate - more likely mL/hr

MunoRN, RN · May 18, 2015

You've got your order which in terms of mg's per minute, for programming the pump you need to translate that into ml's per hour. For converting the mg's to ml's you know the concentration you are using is 140mg per 50ml, and you want to know how many ml's would make 4 mg's the same concentration.

Personally I prefer to cross multiply and divide to solve for the unknown. So if you write 140 / 50 = 4 / x, you take you're two known numbers that are diagonal from each other and multiply them (50 x 4) and then divide by the third known number (140) that will give you the value of x. So 50x4=200, 200 divided by 140=1.43. So if you plug that number back into the ordered rate in place of the 4mg, you've got 1.43 mls/minute. To get that in terms of "per hour", multiply the number of mls per minute by 60, which is 85.8 (86) mls per hour.

To figure out the time it takes to infuse it's probably easiest to use the mls/minute. If you're infusing 1.43 mls every minute then how long will it take to infuse 50 mls?

SierraBravo · May 19, 2015

Interesting! I learned something today with your question. Thanks! High-dose IV therapy for Lasix is max 4 mg/min as compared to IVP at max 40 mg/min. We don't do Lasix drips on the floors I work on.
If the question is indeed drops per minute (I question that too), then you need to know the drips/ml for your tubing. That's not in the question you posed, so you can't calculate without that information.

All of the resources that we have at our hospital state that 20mg/minute of furosemide IVP is the maximum rate, or else you can cause ototoxicity to the patient. I would be very cautious about pushing furosemide at 40mg/minute.

dudette10, MSN, RN · May 19, 2015

All of the resources that we have at our hospital state that 20mg/minute of furosemide IVP is the maximum rate, or else you can cause ototoxicity to the patient. I would be very cautious about pushing furosemide at 40mg/minute.

Our in-MAR admin information states 20-40mg per minute, which is what all the references I just googled also say.

canigraduate · May 29, 2015

I cannot figure out the answer to the following question - every time I try, I keep getting different answers - please help me solve it/work it out.
I have to administer 140mg IV Lasix in 50 mL. Knowing that I can infuse a maximum of only 4mg/min a) how should I program the pump (drops/min) and b) how long will the drug infuse over?

Well, a) you can't, and b) divide 140 by 4 to get your minutes.

Once you have your minutes, you know it's 50 mL, so convert that to ml/hr to program a pump with.

If the question really did mean gtt/min, then you will need to come back with a drop factor for your tubing.

In my drug books (Lippincott and Davis), it always says to give IV lasix at 4mg/min or less to prevent ototoxicity. Which references are y'all seeing that say up to 20 min for IVP?