dosage calculation

[waterwater]

hi there,anyone please help me how to solve this dosage calculation using dimensional analysis.

A patient is to receive Digoxin 0.25 mg IV push at a rate of 0.5 ml/minute. The ampule contains Digoxin 0.25mg/ml. How many milliliters of Digoxin would you administer and over how much time would you administer this dose?

[CrazierThanYou]

I still can't get the answer to this question. I can't figure it out how to set it up.

I have: .25mg ....... 0.5mL

...........______ x ________ = mL

..............mL ..........1 min

I am leaving something out...

Sorry, its been a long time since I've been to school or done math!

Um, maybe this will show up right!

[braithiar]

Make sure you start with what you're looking for. You're looking for time, so start with minutes. Flip 0.5mL/min (so you would have 1min/0.5mL) and then get the units to cancel until you are left with only minutes.

-B

[TheSquire, DNP, APRN, NP]

The way the question is set up it wants you to do the problem stepwise. Go from mg Digoxin to mL Solution to minutes of pushing. Remember that your conversion factors, such as 0.25mg Dig/1 mL solution, are equivalent to each other and, as manifestations of 1, can be flipped (e.g. to 1 mL solution/0.25mg Dig).

[braithiar]

lol.

TheSquire and I will get you through this. Apparently we are both watching this thread like hawks. I've even brewed some coffee to keep me alert.

[dudette10, MSN, RN]

hi there,anyone please help me how to solve this dosage calculation using dimensional analysis.

A patient is to receive Digoxin 0.25 mg IV push at a rate of 0.5 ml/minute. The ampule contains Digoxin 0.25mg/ml. How many milliliters of Digoxin would you administer and over how much time would you administer this dose?

I really don't understand why nursing schools make you use a particular method of calculation. I don't use dimensional analysis, I don't "get" it, and I never will. I use proportion method usually, but there are other times where no pen-and-paper calculation is needed. This is one of those times.

This one, you can figure out without doing the math. If the ordered dose is 0.25 mg, and the amount available is 0.25 mg/1 ml, well you need to give 1 ml, right?

If you give 0.5 ml over one minute, you'd give 1 ml over 2 minutes.

No calculation needed. Using dimensional analysis for all problems--especially if you don't understand how to do it--will just get you in trouble in the real world. Dangerous, I say.

Students need to figure out the method that works for them, then use it over and over during dosage calcs in school. To force a certain method all the way through school that a student can't "get" is pretty much setting up a student to make med errors when he/she becomes a nurse. Ridiculous.

[TheSquire, DNP, APRN, NP]

I really don't understand why nursing schools make you use a particular method of calculation. I don't use dimensional analysis, I don't "get" it, and I never will. I use proportion method usually, but there are other times where no pen-and-paper calculation is needed. This is one of those times.

This one, you can figure out without doing the math. If the ordered dose is 0.25 mg, and the amount available is 0.25 mg/1 ml, well you need to give 1 ml, right?

If you give 0.5 ml over one minute, you'd give 1 ml over 2 minutes.

No calculation needed. Using dimensional analysis for all problems--especially if you don't understand how to do it--will just get you in trouble in the real world. Dangerous, I say.

Students need to figure out the method that works for them, then use it over and over during dosage calcs in school. To force a certain method all the way through school that a student can't "get" is pretty much setting up a student to make med errors when he/she becomes a nurse. Ridiculous.

So you just did dimensional analysis in your head - because you understood the math and knew how to set up the problem. The issue is more that our math-phobic culture promotes ignorance of simple arithmetic and algebra, which nursing students have to be reintroduced to in order to be able to do basic calculations. I like DA and promote it heavily because, unlike the other methods, it is malleable and can handle any dosage problem. Memorizing formulas might help some students, but makes them worse nurses, because they don't understand the math behind what they do.

Tangentially, one of the nice things about doing DA on drug dosages as opposed to random experimental setups is that drug dosages are designed to make the math as nice as possible, with lots of canceling out on both sides and the like.

[TheSquire, DNP, APRN, NP]

I really don't understand why nursing schools make you use a particular method of calculation. I don't use dimensional analysis, I don't "get" it, and I never will. I use proportion method usually, but there are other times where no pen-and-paper calculation is needed. This is one of those times.

This one, you can figure out without doing the math. If the ordered dose is 0.25 mg, and the amount available is 0.25 mg/1 ml, well you need to give 1 ml, right?

If you give 0.5 ml over one minute, you'd give 1 ml over 2 minutes.

No calculation needed. Using dimensional analysis for all problems--especially if you don't understand how to do it--will just get you in trouble in the real world. Dangerous, I say.

Students need to figure out the method that works for them, then use it over and over during dosage calcs in school. To force a certain method all the way through school that a student can't "get" is pretty much setting up a student to make med errors when he/she becomes a nurse. Ridiculous.

Additionally, I am opposed to giving out answers on the message board - not only because it defeats the point of having the student work through the problem but also, if it is part of an assigned problem set, giving the OP the answer constitutes Academic Dishonesty. Poking and prodding the OP to get them to figure it out for themselves is one thing, giving them the answers outright is quite another.

[braithiar]

OP & CrazierThanYou -> Any success?

[CrazierThanYou]

I feel like a real idiot. My problem is setting the problem up. Always has been, that's why I had so much trouble with word problems in school.

The one poster gave me the answer so...

[braithiar]

True, the answer was already given, so here you go:

min = 1min/0.5mL * 1mL/0.25mg * 0.25mg = 2min

-B

[braithiar]

There are many people in the world who have trouble with math, so you shouldn't feel like an idiot. It's a practiced skill. Keep doing problems and it will make sense eventually.

-B

[SC APRN, DNP, APRN, NP]

Hi,

I've been using dosagehelp.com. I think its very helpfule. They even email you a question every day.