laughing gas???

Has any one thought about laughing gas during birth?? I went completely natural with my first and I plan to do so again. But I was reading about it and it got me thinking about trying it. Maybe just for contractions, I read if you want to stop you just breathe the regular air. I'm not sure if they use it in the country I live yet my next appt. I'm going to ask my dr. Seems ok to me but I think I might just go natural again