In any discussion of an emergency room or an emergency department or an emergency service, a definition of the terms of reference is always helpful at the start. Unfortunately, definitions of what constitutes an "emergency room" are not easily found and although numerous regulations governing hospitals refer to the provision of emergency service, none have hazarded a precise definition. Thus far, definitions all seem to be in agreement that personnel, materials and regulations should be present to insure immediacy or promptness of care. But uniform agreement on how immediacy and promptness are to be provided does not seem to be present in the authorities that we have consulted.
Charles U. Letourneau, Legal Aspects of the Hospital Emergency Room, 16 Clev.-Marshall L. Rev. 50 (1967)