How many categories can discourse support?

Group PMs work great for the team here on Meta. In your case, it sounds like you would have a PM between

  • the patient
  • the assigned medic(s)
  • the @support_staff group

The support_staff group would benefit from our polished group inbox view, where messages can be “archived” after it’s determined that the group has nothing more to do with the message as it stands.