Reconstitution HELP Pleaseeeeeee!!!!!!! :(

[HalfMoons]

I'm having a hard time understanding a certain group of reconstitution problems and my ATI is useless...

Here's the question:

A patient is to receive 300,000 units of a medication. The reconstitution directions read:

1) Add 5.5 ml to yield a concentration of 600,000 units/mL

2)Add 6.3 ml to yield a concentration od 400,000 units/mL

3) Add 7.6 ml to yield a concentration of 200,000 units/mL

Which concentration should the nurse use? Why?

I chose #1 and said b/c it's easier to withdraw half of one vial than to withdraw 1/3 or use 2 vials

How much sterile water should the nurse add to the vial?

I got 2.75mL (i just halfed the 5.5mL for this answer)

How many mL should the nurse administer to the patient?

I got 0.5mL (i did the D/H x mL, but idk if i'm even supposed to use it for this?!)

I have a bunch of these questions and I really think i'm doing them wrong b/c how can what the nurse administers be less than the mL that was added to the reconstitution in the first place?! Am I missing something blatantly obvious (this is a major possibility, which is why can someone please please pleaseee help me!)

[nurseprnRN, BSN, RN]

Perhaps the faculty want to be able to learn which students can see there's more than one way to, um, skin a cat (with apologies to the student who's squeamish about anatomy lab).

Hint: When something says, "...for a FINAL CONCENTRATION OF...." that's where you find what you need to get your answer.

[Esme12, ASN, BSN, RN]

I'm sure you will agree that one miscalculation in one post (out of the thousands, no doubt, you have answered) hardly makes one an idiot. The baby let me sleep last night. :-) You are forgiven.

LOL.....I love you Ashley.........and a cutie pie she is!!!!!!!!!!!!!!!!!!!!!!