Aspirating an air bubble

I recently started working in a pediatric office where today I gave a rocephin injection IM. We don't normally aspirate with vaccines but with rocephin we do. Since I don't aspirate much, because we do vaccines more, I'm a little concerned about an incident today. When giving a rocephin today to a 9 month old I aspirated, no blood return but what looked like an air bubble formed. I proceeded to inject the medication and then went on the rest of my day not thinking much about it til now. Was that incorrect to inject the air bubble? Will it harm the patient? Still learning ! Thank you!
I always aspirate a glute shot, but not deltoid. Of course, I don't have to inject babies which suits me fine. But I've never heard of aspirating an air bubble. I don't think small amounts of air IM do any harm. Hopefully you get some posts from someone who's up on the latest and greatest.

Thank you for your response! It was given in the thigh, not arm. Just thought I'd clarify...

I was able to talk to someone I work with and they said yes that's just fine as long as there is no blood.

The air bubble was most likely not air but rather vacuum. This is much easier to do with smaller gauge syringes. As an experiment, close the cap tight on a syringe and pull back on the plunger, then let go.

If you don't pull back blood, something has to "fill" the extra volume you have now created in the syringe (either that or the syringe has to collapse on itself). The irony to it, it that the space is "filled" with nothing--i.e. a vacuum, as Asystole stated. And, even so, it is OK to inject air--remember the airlock technique for IM injections.

As an unlucky one-time recipient of a Rocephin IM injection, I hope it had lidocaine in it.

Quote from TriciaJI always aspirate a glute shot, but not deltoid. Of course, I don't have to inject babies which suits me fine. But I've never heard of aspirating an air bubble. I don't think small amounts of air IM do any harm. Hopefully you get some posts from someone who's up on the latest and greatest.