If you want blood you got it AC/DC , could make it worse though. Sharpies Rule.
A long time ago, I heard a guy say the best song a band can play during a bar fight was Silent Night.
Evidently, it can make guys stop in their tracks. It must be difficult, or at least awkward, to try to kick someone's ass when a Christmas hymn is playing in the background.
I would approach this situation in 1 way:
I'm not saying you have to use it, but that noise it makes will snap anyone out of a fight as they get to close to you.
Pepper spray is legal to possess in all 50 states.
The problem with pepper spray is that it will indiscriminately affect the entire bar for the whole night. Its use will likely result in a quantifiable loss of revenue to the bar, which puts you in a position of civil liability. The other issue is the angry drunken mob you've just created.
The other issue is that PS doesn't immediately deter highly motivated individuals. I speak from experience, having been maced and managing to disarm and incapacitate the assailant prior to experiencing the second worst night of my life.