requirement for CRNA

I'm pretty positive most schools want at least 1 year recent experience. Best thing to do is call the school and ask.

As you know, the field of medicine/nursing changes fairly rapidly. Recent experience would be best. Get yourself as proficient with all of the drugs, ventilators, invasive lines/techniques as possible. I would also suggest that you try to make some arrangements with one of the CRNA's in your facility to shadow him/her for a few days if possible.

You need recent experience.