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.

[akulahawkRN, ADN, RN, EMT-P]

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

Second question... Might be a good idea to determine the concentration of Pitocin per mL. Then you can either determine how many U/Hr and find the mL/hr that way or find how many mL/min and then from there how many mL/hr.

Third question... You're going to need to convert lbs to kg and determine the concentration of med per mL.

Post back what you've come up with. Actual answers, I'll not give... but point you in the direction of it, I will!

[mb1323]

That's what the first question has. Really confusing.

For the second question I've got units per ml after dividing 20 by 500. I've got my units/ml but I don't know what to do from there.

I was thinking multiply it by the .002 or multiply the .002 X 60 then multiply.

3rd question I've got 68.2 then I multiply that time 5.2.

[mb1323]

I got 3 for #2

[akulahawkRN, ADN, RN, EMT-P]

According to my calculation, you're correct about #2. It's 3 ml/hr. It's probably easiest to convert U/min to U/hr and go from there. As for #3, are you certain that it was given in mg/kg/min and not mcg/kg/min? The reason I ask is because the whole amount would be gone in about 42 seconds...

[mb1323]

Ya it's mcg. I got 1020

As the answer for that one.

[akulahawkRN, ADN, RN, EMT-P]

For #3: find how much dobutrex is needed per min. Convert lbs to Kg. Then 5.2x that result = mcg/kg/min. After that, it's a matter of figuring out the concentration of med in the bag, converted to mcg instead of mg. From there, just figure out how many ml's you need to deliver that much med in that one minute x 60 and you'll have your answer. Trust me, it's a LOT lower than your answer.

[chare]

Magnesium sulfate 50% refers to the concentration of the solution. A 50% solution contains 50 grams dissolved in a total concentration of 100 mL.

With the information available you can determine the volume of magnesium you need to withdraw.

[mb1323]

For the first question I got 80

[mb1323]

And I got 21.3 for #3

[mb1323]

I got 17 for the last question.

[furelite]

I got 17 as well for 3. As for # 1, 50% concentration 50g/100 mL = 10g/20 ML = 1 gram/2 ML (at least that's how I see it). Correct or not?