to aspirate air or not when taking meds from vial?

[pixyforest]

hi! please help im confused, i just want to know if i still need to aspirate air if i want to get the vial's content or should i just inject straight in and aspirate the content? because sometimes i can aspirate the contents straight from the vial with no problem but other times there is resistance and the only way for me to take the solution is to aspirate air then inject the air inside the vial before i can aspirate the content. how will i know if a particular vial needs air aspiration or not? thanks!

[MPKH, BSN, RN]

When taking medication from vials, you inject the same volume of air as the dose into the vial before you withdraw the medication. So for example, if your dose is 5ml, you would inject 5ml of air into the vial and then take out 5ml of the medication. All medications stored in vials are required for air injection prior to medication withdrawal.

[Double-Helix, BSN, RN]

First, understand the reason why you're taught to inject air. Medications are stored in air tight vials. The theory is that, due to the pressure inside the vial, it's imposible/difficult to withdraw the medication due to the unequal pressure in the vial. So you inject air equal to the amount that you want to withdraw to create positive pressure in the vial. Then it's easier to withdraw the fluid and equalize the pressure.

In real life, there are vials that don't require you to inject air first. The general rule is that if you're only drawing up a small amount of the medication in the vial (such as an insulin dose from a multi-dose vial or 1mL from a 10mL vial) then you probably don't need air. In the case of multiple use vials, they tend to lose the air tight seal due to all the punctures and don't require air).

Where you will need air when you're withdrawing all of the medication in a vial or using a really large volume vial, such as mannitol. Mannitol usually comes with 50 mL in a vial and is extrememly difficult to draw up, even with air.

There's no harm injecting air, so it's easiest just to do it each time. Here's a hint, though. Make sure you either 1. Inject slightly less air then you need to draw up or 2. Turn the vial back upright before withdrawing the needle. There have been multiple times when I have injected air into a vial, drawn up my needed amount and taken out the needle. Due to the pressure caused by the air, the medication squirts out of the puncture hole in the rubber. (This only happens if you inject too much air or you're not drawing up all the medicine.)

[mindlor]

Bottomline is this....if you want to pass clinicals you will inject air......get into the habit.