Help with 3 practice questions

[mb1323]

Med order: magnesium sulfate 2 g IV

Available: magnesium sulfate 50% in 20 ml.

How many ml will you administer?

I can't figure this out.

The 2nd question is

The pt. is to receive 500 ml of D5w with 20 units of pitocin at a rate of 0.002 units/min.

How many ml per hour will the pt. receive?

Last question:

The med order is to administer dobutrex at 5.2 mg/kg/min. Pt weighs 150 lbs.

Prepare the iv sol. By adding dobutrex 250 mg to 200 ml of d5w.

Calculate flow rate in micro drops (60 drops per ml).

Any help would be greatly appreciated.

[mb1323]

For #1 would it be 4 ml? I have no idea.

[chare]

For #1 would it be 4 ml? I have no idea.

Rather than just posting your answer, show your work as well; this will allow us to better assist you.

[mb1323]

From what they give me in the question I would say there is 10 ml of magnesium sulfate in that 20 ml vial.

And 1 ml=1 gram. The answer I come up with is 40 ml to get to 100%

[chare]

For #1 would it be 4 ml? I have no idea.

Yes, 4 mL is the correct answer.

There are many formulae that can be used to solve this; however, when I work this type of problem I use the following: (D ÷ H) × V. D represents the dose that you need to administer, H is the amount that you have available, and D is the volume for H.

For example. You are caring for a hypoglycemic patient who weighs 15 kg. The physician orders 0.5 g/kg, or 7.5 g of intravenous D25. D25 is available in a 25 mL vial. How many mL of D25 do you administer?

(7.5 ÷ 25) × 100 = 30 mL

When solving this type of problem, the important information is the concentration and the dose. Always use the amount of medication and volume that you determined from the concentration.

[Goose Xx, MSN, RN, EMT-P, CRNA]

% Solutions are easy to figure out.

0.5% solution = 5 mg / ml

0.75% solution = 7.5 mg / ml

1% solution = 10 mg / ml

2% solution = 20 mg / ml

50% solution = 500 mg / ml

See the trend. Take your percent and multiply by 10. Simple decimal position change.

So for this problem you need 2 grams. 50% solution = 500 mg / ml. 4 x 500 mg = 2000 mg or 2 grams.

[nurseprnRN, BSN, RN]

First question... there's something missing that is preventing you from answering the question.

No, there isn't anything missing. Unless it's the fact that the OP doesn't remember how to figure out what a 50% solution means... Look that up and then try again.