So, today I was doing a spinal for a THA. The only thing different is that I would typically go to a 22G Quincke for a paramedian approach (which I started out with after noticing her spinous processes being very prominent (thin lady) but very very tight). What I did was use (because I had forgotten to drop the 22) the regular 25 G with the introducer and sort of guessed correctly on my angle, and accessed the IT space with one small redirect. I got very good CSF flow, no parasthesia, and I did not suspect that I was somehow intraforaminal. So, I pull back a bit of CSF with my marcaine syringe hubbed just as well as I typically will snug it. The typical BBraun luer slip (vesus luer lock) syringe. But, when I pulled back I pulled back quite a bit of air bubbles WITH CSF. I repositioned the needle (after tapping the air out of my syringe), got great CSF flow, hubbed it again, this time with a tighter fit, and the same thing happened. Ultimately, I just injected (after again ridding the air from my syringe), and hoped for the best. Interestingly, the patient did just fine. Maybe a slight tolerance deviation when I aspirated back and atmospheric air got entrained in the marcaine spinal syringe??? Has anyone experienced this before? This was a first and we do a ton of neuraxial.