6:26 PM PT -- Austin North just addressed the situation online, and he says he was having a very severe panic attack where he thought he might die ... adding he doesn't remember much of the incident at all.

AN posted a lengthy description of what he says happened that day -- noting he's been dealing with this condition for a long time, and that the attack he endured Tuesday was by far the worst he's ever experienced. He apologizes to the hospital staff, and says he hopes to shed more light on his condition as time goes on.

Austin North went haywire at a hospital in Vegas this week -- attacking several emergency room staffers and needing to be restrained ... so claim cops, anyway.

According to the police report, obtained by TMZ, officers were dispatched to UMC Hospital Tuesday night for reports of an assault and battery that had occurred in the ER ... and when they arrived, cops say they interviewed the alleged victims.

According to a couple nurses and a phlebotomist -- who claim to have been struck by Austin in a bum-rush they say came out of nowhere -- the actor was throwing fists and shoving all three of them in succession ... for no apparent reason whatsoever.

He's alleged to have punched a nurse in the head, shoved the face of another nurse and pushed the phlebotomist into a table -- only for the latter alleged victim to use a tray nearby to smack him in the head in self-defense.

At this point, cops say Austin was restrained by security officers ... but he's alleged to have attacked one last person -- although it's not clear from the report what her job was.

In any case, they finally cuffed him to a gurney there in the hospital. The cops who arrived to deal with this say they read Austin his Miranda rights when they told him they were arresting him for battery, and when asked if he understood ... they claim he said "yes."

He was hauled off to jail, where he was booked for gross misdemeanor battery ... and posed for this mug shot. Austin has since bonded out. The one thing that isn't addressed in this whole narrative is ... what the hell was he doing in the ER in the first place???

That remains to be seen ... but it's a very bizarre hole in the story. Interestingly enough, Austin was kinda documenting his weekend in Vegas -- the dude has a whole compilation up on his social media page that shows off everything he was up to ... and it looks like a lot.

We've reached out to his team for comment ... so far, no word back.