All doctors see these patients. We recently had one obnoxious patient who scared my staff for days. We had to kick him out of our practice to maintain sanity. My colleague had a violent female patient who crashed into her car and had to get a restraining order from the Court.
http://www.cnn.com/2007/HEALTH/07/11/nurse.violence/index.html
Back in the old days, when I worked in Toledo, Oh, many of us carried ankle holsters in the ER, usually with a short barreled .357 or something of similar stopping power.
But you've got to keep in mind the area. It was Mercy Hospital in downtown Toledo. The parking garage was separate from the hospital without a covered walkway. Employees complained about getting wet in the rain and so the hospital admin remedied it by buying some large, bright blue umbrellas emblazoned with the Mercy Hospital name. They placed them in the parking garage conveniently next to the elevator. Within 24 hours, every prostitute on the main thoroughfare adjacent to the hospital was plying her trade under a Mercy Hospital umbrella. It was not a great area of town.