math help!!

Show us your calculations so far? What is confusing you?

I have nothing. I tried it several different ways but can't come up with the right answer. Its the only one out of 50 that has me stumped!! I have the correct answer of 48 ml/hr...just don't know how to get there.

Any help will be appreciated, but I am stumped!

Order: Dobutamine 250mg IV in 500 ml D5W to infuse at 5mcg/kg/min. Mr O weighs 80 kg. What is the flow rate in ml/ hr?

I know it is probably simple lol...pls help!

I won't do the problem, but just looking at the question:

I always look at what the question is asking me first because then I know what I have to deal with.

Okay, so have to have a flow rate in "mL" per "hour".

You have an order for 250 "mg" per 50 "mL" .

You also know the formula is in "mcg" per kg per "mnute"

You also know you have to plug in the 80 kg into the forumula.

So, given the info you have, how do you get mL per hour? If you do the conversions and solve for ml per hour, you should be okay. You can solve using ratio or using dimentional analysis.

lady is correct, the first part of the problem is finding out what units the answer needs to be in. lately i've been using dimensional analysis. i won't do the problem for you either but i can help you understand what we mean by dimensional analysis.

example: say you have 10g medication x in 1000ml and you have an order to run it at 50 mg/hr and you are using a drip factor of 60. how many drips/min do you need to run at?

step 1: find the units you are using for the answer.

gtts

____ = ?

min

step two: start looking at the information you do know and line it up so it that the all the units cancel out to leave only the units you want. you will have to fill in conversion factors along the way.

gtts = 60 gtts 1000ml 1g 50mg 1 hr

____ ________ x ________ x _______ x ______ x ______

min 1 ml 10g 1000mg 1 hr 60 min

step three: double check and make sure all your units cancel. if you did it correctly the only stuff left should be in the format of your answer if not try to figure out where you went wrong.

gtts = 60 gtts 1000[color=#ee82ee]ml 1[color=#b22222]g 50mg 1 hr

____ ________ x ________ x _______ x ______ x ______

min 1 [color=#ee82ee]ml 10[color=#b22222]g 1000mg 1 hr 60 min

step four: multiply the top units all together

60 x 1000 x 1 x 50 x 1 = 3000000

step five: multiply the bottom units

1 x 10 x 1000 x 1 x 60 = 600000

step six: divide the answer you got in step four by the one in step five

3000000

_______ = 5 gtts/min

600000

hope that helps you figure out how to do it on your actual problem. try it out and let us know how it goes.

double check and make sure all your units cancel. If you did it correctly the only stuff left should be in the format of your answer if not try to figure out where you went wrong.

The one step that most stuents skip is checking their work. ALWAYS, ALWAYS CHECK YOUR ANSWERS. If plugging in the answer does not give you the info you need, then there is a problem someplace.

I took my math test this morning and got 100%....thank you for your help!!

I took my math test this morning and got 100%....thank you for your help!!

That's awesome, congrats! Happy to help.

congratulations nolli, for giving the best explanation of why dimensional analysis works that i have ever seen. ::looking around for [color=#daa520]gold star icon:: :yelclap:

Aww thanks GrnTea. Honestly though I'm not a huge fan of math so I feel for anyone else who had the same issues I did when I got my first glimpse of medmath.

Can you show us how you did it. I haven't started the nursing program, i just want to get a feel for those kind of math problems.

I convertd the 80 kg to 176 lbs and plugged it in the problem

500 ml/250 mg x 1 mg/1000 mcg x 5 mcg/ kg * min x 1 kg/2.2 lbs x 176 lbs x 60 min/1 hr

= 26400000/ 550000 = 48 ml/hr