Well, from what Casino has seen, they are strapped with heavy autopistols (those are the weapons they've taken out to deal with the threat). They have Beretta 1010 MP medium submachine guns in their squad car. Casino can easily imagine that the two of them have some sort of holdout on their persons... maybe even two. Casino's Automag was confiscated and put in the trunk of the squad car when they loaded Casino up.
Welcome to Casino's own version of Die Hard!
Exits? For ease of imagination, consider the room that Casino is in to be 20 meters by 30 meters with the entrance to the actual emergency room at one end of the 30-meter stretch and the exit to the parking lot (the area these goons came through) at the other. The three of you would be about 10 meters from the emergency room door. There's also another door to the left as you're heading towards the emergency room at about the 15-meter mark that looks like it heads deeper into the hospital, but this door is already past the furthest progression of the gunmen.
The emergency room nurse's station is behind bulletproof glass in a booth just to the left of the emergency room door as you're approaching it. There are two of those vacuum cleaner looking bots that distribute morphine in the room, but they are 5-meters and 8-meters away, respectively.