Pre-charging Vial with Air-Filled Syringe

AstronomyNerd86 · Oct 23, 2011

We had our skills test this past week for injections and med passing. Here is what we were told to do, by our instructors and our books. Draw air into the syringe equal to the amount of medication you will want to obtain from the vial and inject the vial with the air. Do this in the airspace, above the medication. If you inject the air into the medication, then it can cause bubbles to form in the medication, only complicating the procedure. By injecting air, if will create a pressure in the vial which will allow you to easily draw up the actual medication. Once you push the air into the vial, with the needle still in the vial, tilt the vial upside down so that the needle is now in the medication and slowly draw up the amount of medication needed. We were told to draw a tiny bit more than needed so that if we do get an air bubble and need to get rid of it, we will still have the amount of medication needed. Then if after you get rid of the air bubbles and still have a little extra medication in the syringe, you can always expel it, make sense? As for getting rid of the stubborn bubble that always seems to be stuck on the little plunger, is your needle still in the vial when you tap the syringe to get the bubble to go up? If so, try taking the needle our of the vial, safely recapping it (so long as it is an UNUSED needle), and then flicking the syringe to get the bubble to release. Some students in my clinical were trying to get the bubble to release when the needle was still in the vial, but our instructors told us to take the needle out of the vial, then flick it because it's easier to flick the syringe harder. I hope this helps and doesn't confuse you even more. It's hard to explain in words everything.

PsychNurseWannaBe, BSN, RN · Oct 23, 2011

our textbook says to inject the air from the syringe into the airspace of the vial to avoid forming bubbles. but the video that comes with the textbook shows the opposite. then i found another educational video which specifically says to keep the tip of the needle "below the level of the medication" when introducing the air to charge the vial. i am concerned because no matter how many times i practice, i see very small bubbles clinging to the end of the rubber plunger. no matter how hard i tap the barrel, the bubbles stay there.

i stay below the line of medication.

then i am confused in another scenario where the medication is aspirated using a blunt needle. then that needle is switched for a fresh needle to inject the patient. but isn't the new fresh needle full of air? if you were to push that air out before injection, wouldn't the dose in the syringe now be reduced? the more i practice this skill and watch videos online, i am wondering if it is all just an imprecise technique where you wing it. it is very frustrating because so many sources seem to conflict with each other.

switching from a blunt needle to a regular needle does not change the amount of medication in the barrel of the syringe. i normally push a little forward to expel air out of the newly placed needle.

Zaptastic · Oct 23, 2011

We were told to draw a tiny bit more than needed so that if we do get an air bubble and need to get rid of it, we will still have the amount of medication needed.

When you are expelling the air bubble during that step, do you once again have to move the tip of the needle above the fluid level into the airspace?

Some students in my clinical were trying to get the bubble to release when the needle was still in the vial, but our instructors told us to take the needle out of the vial, then flick it because it's easier to flick the syringe harder.

I tried that, but doesn't the bubble just move to the top and now inside the needle ready to cause an air embolism fatality? I tried moving the plunger very slowing in an attempt to just expel the bubble and no medication. But it seems impossible because I was moving it maybe 1/1000 of an inch and still some medication would come out the top indicating that I now would have a reduced dose inside the syringe and fail the test. Also I was flicking the syringe many many times as hard as I could but still saw bubbles at the bottom. I will try to take a picture.

Zaptastic · Oct 23, 2011

It was hard to take a clear picture because my camera didn't want to focus that close:

Zaptastic · Oct 23, 2011

i stay below the line of medication.

then wouldn't that introduce bubbles into the fluid still in the vial?

switching from a blunt needle to a regular needle does not change the amount of medication in the barrel of the syringe. i normally push a little forward to expel air out of the newly placed needle.

but by expelling the air out of the needle and replacing it with medication, aren't you reducing the injected dose? after completing an injection when the plunger is bottomed out, there is still fluid in the needle. if that is taken into account by the manufacturer when placing the fluid measurement lines on the side of the barrel, then by filling the new needle with medication, you've just moved the plunger past the prescribed ml line haven't you?

AgentBeast, MSN, RN · Oct 23, 2011

Yeah, the only reason to get the air out of a syringe when giving IM, ID, or SQ injections is to ensure an accurate measurement. You aren't going to kill somebody if you inject air into muscle, fat, or skin.

Zaptastic · Oct 23, 2011

OK, thanks.

PsychNurseWannaBe, BSN, RN · Oct 23, 2011

then wouldn't that introduce bubbles into the fluid still in the vial?

this shouldn't be an issue. the bubbles will separate out of the fluid and into the empty space.

but by expelling the air out of the needle and replacing it with medication, aren't you reducing the injected dose? after completing an injection when the plunger is bottomed out, there is still fluid in the needle. if that is taken into account by the manufacturer when placing the fluid measurement lines on the side of the barrel, then by filling the new needle with medication, you've just moved the plunger past the prescribed ml line haven't you?

there will always be a little medication left in the used needle. but we are talking very very tiniest of amounts. you do not adjust the amount drawn up to compensate for that.