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EMS in the United States is a hierarchical care delivery system, with physician leaders working in partnership with EMT/paramedic providers to rescue, care for, and transport patients. Alternative system structures are possible, and work well in other countries and settings. These include both systems with more physician involvement (physicians routinely staffing ambulances), and systems where EMS providers organize and manage their system with little or no physician input. The US model includes a robust prehospital emergency care network in which care is directly provided by predominantly nonphysician prehospital providers. The physician role in this type of system is heavily weighted toward oversight and direction of the system and through direct contact with providers in the field when called for medical control. This chapter will provide an overview of these topics and following chapters will provide greater detail on each of the elements discussed.


  1. Define the terms medical control, medical direction, and medical oversight.

  2. Describe online (telecommunications and in person) and off-line medical direction.

  3. Discuss qualifications for providing medical direction.

  4. Describe proper base-station training for EM and EMS physicians.

  5. List the components of medical oversight.


Although not explicitly stated in some of the original governmental documents describing the EMS system in the United States, medical direction and physician oversight have always been key components to the development and operation of prehospital emergency care services. Although it has been surmised that physician involvement was always assumed, later documents specifically call for medical oversight. This function has evolved over time and can be described in terms of four general types of physician involvement.


Online medical control, also known as direct medical control, refers to consultation between EMS providers and a physician, typically by radio or telephone, to guide care for an individual patient or EMS incident. These physicians are usually required to take a base-station course and maintain up-to-date knowledge of the EMS treatment protocols. The majority of the physicians providing this type of medical control are not EMS physicians or EMS agency medical directors. Typically, they are the emergency physicians on duty in receiving emergency departments (Figure 4-1). However, in some cases they may also be assigned this duty exclusively when working a medical control shift in a larger system. Another form of online medical control is on-scene medical control. This refers to the presence of the physician at the patient's side during EMS care, working directly with EMS providers to deliver care (Figure 4-2). These physicians may be referred to as EMS physicians or flight physicians. When the on-scene EMS physician is also the medical director, this allows for four components: (1) provision of orders and direction of care, (2) evaluation of provider performance, (3) provision of postincident education, ...

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