PLEASE HELP!! Math Reconstitution

[sleepingbeauty7]

I cannot figure out these problems my teacher gave us. Please help! IDK what i am going wrong?

Calculate mL/hr to set the IV pump to infuse Erythromycin 800 mg. Erythromycin supply: 1 g vial to be reconstituted with 20 mL sterile water and further diluted in 250 mL NS to infuse over 1 hour.

_________________mL/hr

Calculate mL/hr to set the IV pump to infuse Gentamicin 80 mg IV q8h. The vial is labeled 40mg/mL and is to be further diluted in 100mL D5W to infuse over 1 hour.

____________________mL/hr

Calculate mL/hr to set the IV pump to infuse Fortaz 1 g over 30 minutes. Supply: Fortaz 1 g/50mL.

_____________________mL/hr

Thank you so much!!

[SolaireSolstice, BSN, RN]

More people will be willing to help if you show what work you have so far.

[sleepingbeauty7]

Calculate mL/hr to set the IV pump to infuse Erythromycin 800 mg. Erythromycin supply: 1 g vial to be reconstituted with 20 mL sterile water and further diluted in 250 mL NS to infuse over 1 hour.

_________________mL/hr

Heres the work i have so far, although i completely do not understand how to do these problems at all.

I put 1000(mg i have of erythromycin divided by 270 ml X 800 mg erythromycin (need) = 216 ml/hr

Which i have found out is not the right answer

Someone please help me, just tell me how to go about plugging these numbers in , i do not need people to give me answers, i will figure it out myself.

[John--RN]

Ok, I am gonna take a stab at this....Keep in mind I am a beginng student......

What i would do differently from you is I would only add 800 mg of erythromycin to the NS.

so 800 mg desired / 1000 mg on hand x 20 ml gives me 16 ml. necessary to equil 800 mg

250 ml NS + 16 ml erythromycin =266 ml

So I would answer 266 ml / hr

Doing it this way does not allow the chance of overdose due to somehow infusing the entire iv

Hopefully someone more knowledgeable will stop by and give us a definative answer.

John

[sleepingbeauty7]

Ok, I am gonna take a stab at this....Keep in mind I am a beginng student......

What i would do differently from you is I would only add 800 mg of erythromycin to the NS.

so 800 mg desired / 1000 mg on hand x 20 ml gives me 16 ml. necessary to equil 800 mg

250 ml NS + 16 ml erythromycin =266 ml

So I would answer 266 ml / hr

Doing it this way does not allow the chance of overdose due to somehow infusing the entire iv

Hopefully someone more knowledgeable will stop by and give us a definative answer.

John

Thank you John!

I think you got it right! it makes sense to me, and when i apply that method to other problems, i get them right as well. Much appreciated!!

[John--RN]

Cool let me know how you make out...its a learning experiance for me too.

[locolorenzo22, BSN, RN]

i cannot figure out these problems my teacher gave us. please help! idk what i am going wrong?

calculate ml/hr to set the iv pump to infuse erythromycin 800 mg. erythromycin supply: 1 g vial to be reconstituted with 20 ml sterile water and further diluted in 250 ml ns to infuse over 1 hour.

_________________ml/hr

here's my thought. 1g=1000mg right? so you have 1000mg in 20mls of sterile water. to give 800mg, you need how many mls? 800mg/1000mg * 20 mls = 16mls. 16mls plus the 250mls= 266mls....266mls/hr.

calculate ml/hr to set the iv pump to infuse gentamicin 80 mg iv q8h. the vial is labeled 40mg/ml and is to be further diluted in 100ml d5w to infuse over 1 hour.

ok, so using your last problem, figure out how many mls you need to add to the vial, add that to your bag of fluid, go from there.

____________________ml/hr

calculate ml/hr to set the iv pump to infuse fortaz 1 g over 30 minutes. supply: fortaz 1 g/50ml.

_____________________ml/hr

simple, if you think about it. how many mls do you have, and how fast do you need to run it?

thank you so much!!