Sorry I missed this before. As a former psych patient I have had a Doctor in the ED do this for me (i.e take a few moments to sit with me during a panic attack, be reassuring, and offer some basic relaxation/grounding exercises that they thought might be helpful). I really appreciated what they did that night (I should state that it was one of the rare traversing of the sun around the earth kind of moments, where they actually had the time to do this), and tried to arrange a pizza delivery for the ED staff a week later, but was told that wouldn't be appropriate (but hey the thought was there).
Now this is where I'm gonna put a rather large (and probably obvious) caveat on this. In my layperson's opinion there is a huge difference between a patient, like myself that night, who comes in having experienced either a cluster of symptoms that is outside the norm for their diagnosis or is experiencing a sudden acute onset of symptoms that might be considered emergent outside of any psychiatric symptoms, and someone who is just there to suck all the energy out of the room with their entitlement and willful ignorance. Unless you are floridly psychotic, having a mental illness, or disorder, should not give someone the right to not take responsibility for their negative behaviour with excuses like, 'but mah anxiety disorder/adhd/autism/bipolar/tourettes/etc etc'.