HELP! IV push calculation

[treasureu4eva]

I can't for the life of me figure out how this problem works....and why the answers are the answers! Someone plz plz plz help me today! Thanks much appreciated! and if you can break it down for me like I was a dummy that would help alot too :)

Medication Order: Midazolam (Versed) 1 mg IVP

Available: Midazolam 5 mg/mL

Directions: Dilute with normal saline for a total of 0.25 mg per mL and

administer over 2 minutes

How many mL of normal saline will be added?

How many mL per minute will you give?

The answers are:

a. 3.8 mL b. 2 mL/min

[elkpark]

Well, I doubt that you're a "dummy," but here is how I do it:

You're starting with 5 mg of Versed in 1 ml of solution and you want 1 mg of Versed. 1 ml of solution divided by 5 (mg) is 0.2 ml -- so 1 mg of Versed = 0.2 ml

You want to dilute that 1 mg of Versed to 0.25 mg/ml -- that means you want 4 ml, total, of diluted solution (each containing 0.25 mg of the Versed). You're starting with 0.2 ml of Versed solution, so you need an additional 3.8 ml of NS to make the 4 ml total (3.8 ml + 0.2 ml = 4 ml).

4 ml (total) of solution given over 2 minutes = 2 ml/minute.

I've found over the years that what goes wrong for most students with calculation problems is that they freeze up and panic. Stay calm, don't panic, and just think through what the problem is asking you, step by step -- it's really basic math, just a whole bunch of it put together. :)

[treasureu4eva]

How do we get the 4ml of diluted solution??

[elkpark]

Do you mean how did we figure out 4 ml was what we needed, or how do we make the 4 ml of solution that we need?

You have an order for 1 mg of Versed, and the directions for the Versed (in your problem) say to "dilute with normal saline for a total of 0.25 mg per mL." If you have 1 mg of medication and you need to dilute it to 0.25 mg/1 ml solution, how many ml total of solution do you need?

0.25 (mg)/1 (ml) = 1 (mg)/X ( The quick 'n dirty way to do this (if the numbers didn't work out so neatly, you'd have to do the long math) is that 0.25 mg is 1/4 of 1 mg, so that means that 1 ml is 1/4 of the total amount of solution needed -- so 1 ml x 4 = 4 ml)

We are starting with 0.2 ml of the Versed solution (5 mg/1 ml). In order to make the final 0.25 mg/1 ml solution specified in the directions, 4 ml (the final quantity we want) - 0.2 ml (of the Versed) = 3.8 ml (NS needed to dilute to the proper final concentration)

[treasureu4eva]

Thank you ELKPARK, I appreciate you taking the time to break it down for me :)

[elkpark]

You're v. welcome -- I just hope I didn't get you more confused than you were to begin with!

[Gemini85]

.25mg * 4 (since this will make 1mg)

1ml of saline per 0.25mg (we already know we have 4 "o.25mg" units) Therefore, 4ml of saline for the combined 1mg

then take the 4ml/2 since they want u to administer it in 2 minutes.

therefore 2ml/min