BS in other field, how to fastest become a CRNA?

An accelerated BSN would be the fastest, but that's if your prior degree meets all the pre-req's for the Accelerated program. An accelerated BSN is a 12 month program designed for people with prior BS degrees, and is very intensive. If you have a science degree with good grades it's a good option. Many CRNA students have gone this route.

Another option would be to get an Associate Degree RN, many nurse anesthesia programs will accept BS degrees other than the BSN. They take a little longer, but are often less expensive.
Once you pass boards, are an RN, get 2 years experience in a busy ICU. Then you can see if you like the intensity of the ICU and want to go on the a nurse anestheia program. By NP do you mean Nurse Practitioner? That's another type of Advanced Practice Nurse, also requireing a graduate degree after a BSN.

Good-Luck

Look at the how to become a CRNA, FAQ thread on this site. An NP is an advanced practice nurse - which requires graduate level schooling for the experienced RN. You would need to find an RN (nursing) program and then work on (specifically) ICU experience before CRNA school.

Check out www.aana.com as well. That's the national body for CRNA's and there is a lot of good information there such as what CRNA's do, what their scope of practice is, how to be one, etc.... There's a drop down menu on the left I believe it says "becoming a CRNA."

I would do your pre-reqs for nursing school, then a 1 year accelerated BSN. Then get your critical care experience (I suggest at least 2 years). And finally, get in to anesthesia school. You could probably get to that point within 3-4 years, depending on how many nursing pre-reqs you need, if you can get directly into critical care, and how long it takes you to get into anesthesia school.

Good luck!

What's your BS in?

don't forget that if u think in the future you may want your DNP or DNAP you will need a BS in nursing not a AAS.

ever think about taking prereqs for anesthesiologists assistant school? any trouble with this path is that they can't work in a lot of states.