Mercy Hospital St. Louis is the only Level I (highest) Trauma Center among St. Louis area hospitals in St. Louis County. Mercy Hospital St. Louis provides critical care access for St. Louis County, St. Charles County, and the surrounding areas through its Emergency Department, staffed by board-certified emergency physicians, nurse practitioners, physician assistants and nursing staff. Emergency Department physicians provide oversight for several paramedic districts who bring critically injured and ill patients to the hospital by ambulance and helicopter.