IV question

[LPN trying for RN]

Hey everyone. I have a math homework problem that I can't seem to figure out. Any help is much appreciated.

You're working with an IV solution that contains 250 mg of dobutamine in 250 ml D5W. Your patient, who weighs 108 lbs (49 kg) is suppose to receive 6 mcg/kg/min. If the drip factor is 60 gtt/mL, how many microdrops per minute and how many milliliters per hour should be received?

What I have figured out is that the patient should receive 4.2 mL/hr. However, I cannot figure out the mcgtt/min.

I figured out that the patient is receiving 294 mcg/min. but i'm stuck as to what to do next....please help...thanks

[tamadrummer]

You have to take the 4.2ml = 252 drips in the microdrip tubing = 4.2 drips per minute

Basically 4 drips per minute

I am using your numbers from the bottom. If you did the original math right then that is the answer

[LPN trying for RN]

thanks i'm not sure if I did the ml/hr right or not either.....this one has me sooo confused...

[SolaireSolstice, BSN, RN]

Convert the mcg/min into mg /min. Then convert the mg/min to mg/hr. Since it's 250 mg/250ml, your mg/hr will = ml /hr. You've already calculated the mcg/kg/min and I got the same.

I got a completely different mg/hr than you though.

49 kg X 6 = amount of mcg/min pt should receive.

That amount converted to mg x 60 = mg/hr

250mg/250ml x the amount of mg/1 hr = # of ml/hr (and I didn't get 4.2)

For the drip factor

(amount of solution X drop factor)/time in minutes = drops per minute

So you take your calculation from above which will give you ml/hr, that's the (amount of solution x 60gtt/hr)/60 minutes = drops per minute.

Someone check my math. That one was hard but mostly because of the number of steps. You need to take it step by step, converting as you go to the final calculations, and it will be easiler if you calculate ml/hr then the gtt/min.

[tamadrummer]

my drug calculator says 17.7 ml/hr

1062 drips hr

[SolaireSolstice, BSN, RN]

I'm still trying to figure out where the 4.2 came from. You got the 294 mcg/min, how did you get 4.2 mg/hr? 294 mcg/min = 0.294 mg/min right? Then 0.294 mcg x 60 = 17.6 mg/hr

No matter which way I do it, I can't get 4.2 anywhere.

Oh well, I always hated these types of math problems. They take so much time to break it down. It's funny how now in the field, I can convert on the fly and not even think twice about it, though I usually have someone check my math if it gets too complicated. Heparin and insulin drips make my brain hurt.

[SolaireSolstice, BSN, RN]

Ok, look you need to do the math again.

Double check me but I believe that is right.

Where did the 0.6 mg come from? Ack!! Now I'm gonna start over from the beginning.

ROFL now we're all confused. You're fixing it to I'll just keep going.

[LPN trying for RN]

okay so now i have the ml/hr as 17.64mL/hr....my next question is i have 294 mcg/min but how do i convert that to mcgtt/min??

and thanks so much for your help

[SolaireSolstice, BSN, RN]

ok i got 49 kg x 6 mcg/kg/min = 294 mcg/min

294 mcg/min = 0.294 mg/min

0.294 mg/min = 17.6 mg/hr

17.6 mg/hr = 17.6 ml/hr

then: (17.6 ml x 60 gtt/min)/60 min = 17.6 gtt/min and i'd round it up to 18 gtt/min.

[SolaireSolstice, BSN, RN]

okay so now i have the ml/hr as 17.64mL/hr....my next question is i have 294 mcg/min but how do i convert that to mcgtt/min??

and thanks so much for your help

Use that calculation I gave you up there; it's:

(Amount of solution X drop factor)/time in minutes = drops per minute

[LPN trying for RN]

you guys rock....i have been trying to figure that out for 2 days always got stuck on the 294....and the way i first got the 4.2 is crazy but i just divided 60 into 250.....wrong way to do it but thats how i did it

[SolaireSolstice, BSN, RN]

And does it really say microdrops/min? is that some new conversion I don't know? You can't calculate a microdrop can you?

I'm seriously giggling now, mcgtt? It sounds like something you could order at McDonald's. At least it's not apothocary conversion. Those REALLY made me irritated and luckily we only have like 2 MDs who still order that way.