Keynote Address: Acute Medical Care in the United States
William G. Barsan, M.D.
University of Michigan Medical Center, Ann Arbor
In the United States, acute medical care is delivered in a variety of settings. Although some minor acute care is delivered in physicians' offices and free-standing urgent care centers, the majority of major acute medical care is delivered in hospital-based emergency departments (EDs). The development of hospital-based EDs is a relatively recent phenomenon, evolving in the 1960s. In 1993, there were more than 5,600 hospital-based EDs in the United States serving more than 95 million patients annually (1).
In 1967, Robert H. Kennedy, who had formerly been the chairman of the Committee of Trauma for the College of Surgeons, established the standards for emergency medical services (EMS) in the United States. Although the development of EMS emphasized injured patients, it was recognized that patients with acute medical conditions also required such emergency services (2). The late 1960s also saw the development of the first mobile coronary care units, which became the predecessors for modern advanced life-support ambulance services. The first emergency medicine training program was established in Cincinnati in 1969 and there are currently 110 accredited emergency medicine training programs in the United States (3). Although there are more than 25,000 physicians currently staffing EDs in the United States, there are only 13,000 emergency physicians with board certification from the Amer. Board of Emergency Medicine (1).
Although the systems for care of acutely ill and injured patients are dynamic, acute medical care will likely continue to revolve around the coordination of EMS and hospital EDs. There has been notable success in advancing the care of trauma patients and patients with acute myocardial infarction. This presentation will focus on the structure of EMS in the United States and describe the development of programs for the treatment of trauma and acute myocardial infarction.
The local organization of EMS is not uniform and takes a variety of different forms often determined by historical factors and natural and political boundaries. Although there are many specific structures, five basic types of EMS organizations exist (4).
Fire Service.--This is probably the most common type of EMS structure. In this model, the fire department will coordinate and run EMS. Due to advances in fire detection and prevention, the main business in many fire departments has shifted from fire service to EMS over the last 5 to 10 years. In many areas, fire personnel are used as first responders for basic life-support/emergency medical technicians and will be backed up by paramedics or advanced life-support personnel.
Third Service.--In a third service model, EMS may be governed by municipalities or regional authorities but is separate from police and fire services. In this type of organization, the EMS coverage is not limited to the same municipal areas as the fire and police services.
Private Providers.--Private ambulance companies provide prehospital care on a contract basis throughout much of the country. Although private providers will often provide acute medical care, they are more often used as backups to the acute medical care system and for patient transfers between institutions.
Volunteer Services.--Volunteer EMS providers are more common in small and rural communities. Although these services may be independent, they are often part of a fire department or other governmental agency.
Hospital-Based Systems.--In this model, the prehospital care providers are employed and owned by the hospital or health system. Hospital-based systems frequently will include air medical services as well.
Any system for acute medical care will need to incorporate certain basic components. There must be a method for patients to access the system, some prioritization of the information received from the access call and dispatch of appropriate services, and finally procedures for appropriately trained technicians to respond to the call and provide appropriate care and transport.
Patient access to EMS must be simple and reliable. The method most commonly used in the United States is the 911 enhanced telephone system (5). In parts of the country without 911, other access numbers are used. Regardless of the type of system, public education is vital to ensure that all citizens understand how to access EMS. Public education is also needed so that patients understand conditions for which EMS is essential.
Once EMS is contacted, communication will be with a dispatcher. The dispatcher has several key roles. First, the dispatcher will attempt to assess the nature of the complaint. Based upon the assessment of the complaint, the dispatcher may deliver prearrival instructions for medical care prior to arrival of the EMS providers. In advanced systems, the dispatcher will determine the need for a basic or an advanced life-support response and the priority of the response. A key aspect in measuring the effectiveness of dispatch is maintenance of adequate and accurate time logs that indicate the time the call was received and the time at which EMS arrived at the scene. Most EMS services will have a tiered response system. In a tiered system, medical first responders or basic EMTs will be dispatched immediately to the scene and will assess the patient. Transport to the hospital may be through these first responders. If the nature of the illness or injury is one which requires advanced life support, the first responders will request a second tier or a paramedic response. In some systems, the dispatcher may determine that the nature of the complaint requires an advanced response rather than an initial response by first responders. In these cases, the advanced life-support or paramedic units will be the first responders to the scene.
On-site response requirements for selection and training of personnel at different levels of care will vary from state to state and municipality to municipality. The number of hours of training for paramedic certification can vary substantially from state to state. Standard certifications in order of increasing skill level are first responder, basic EMT, intermediate EMT, and paramedic. Medical direction and control is an integral part of all prehospital systems. On-line medical control indicates communication that occurs between medical control personnel and the prehospital provider usually via cellular phones or two-way radios. Off-line medical control includes all other areas. One form of off-line medical control is patient care protocols. These protocols are by and large developed on a local level and may vary considerably. These patient care protocols will allow the prehospital providers to initiate certain treatments in the field without on-line medical control or physician orders. The patient care protocols may vary tremendously in the degree of autonomy they give to the prehospital providers. For example, paramedics in certain areas can perform rapid sequence intubation in the field using neuromuscular blocking agents.
The destination of the patient after EMS systems are activated may also vary from community to community. For most complaints, patients will be taken to the hospital they request unless standing protocols contravene such requests. In situations where patients are deemed to be unstable, transport to the nearest facility will usually be done regardless of the patient's request. In areas that have a regionalized trauma protocol, traumatized patients meeting certain criteria will usually be taken to a designated trauma center even if this means bypassing a closer hospital or the patient's choice of hospital.
The establishment of trauma systems in the United States and elsewhere has been a major development in the last 20-30 years and has clearly led to improved survival and outcome (6). The impetus for the development of trauma systems occurred primarily through the military experience. It was clearly demonstrated in statistics from World War I, World War II, the Korean Conflict, and the Vietnam War that improving the access of battle casualties to definitive care led to a lowering of mortality.
In World War II, the time from injury to definitive surgical care ranged from 6 to 12 hours and mortality was 5.8%. In the Vietnam War, the average time from injury to emergency care was 65-80 minutes and the mortality was 1.7%. In the United States, development of a trauma system in Orange County, California, led to a reduction in preventable deaths from 73 to 9% when patients were treated in one of five designated trauma centers (7). For patients who were sent inappropriately to a nontrauma center hospital, the preventable mortality rate remained at 67%. It has been estimated that development of regionalized trauma systems will reduce mortality by 33%.
Development of a trauma care system requires a major commitment from medical and health professionals and the public. One of the key aspects in creating public support is to establish the need for improved trauma care. This requires the collection of extensive data on the nature and frequency of injuries, percentage of the population involved in trauma, trauma severity, deaths, and disabilities. Once the need has been demonstrated, legal authority is necessary for the development of such a system. Typically a public agency may be established with the responsibility to develop criteria for the system, establish prehospital protocols, designate appropriate facilities, establish a trauma registry, and monitor quality improvement programs. The key factor in establishing a trauma system is the formation of a team approach to the care of the trauma patient that involves all individuals at every stage of management. This would include prehospital providers, emergency physicians and nurses, trauma surgeons, anesthesia and operating room personnel, and rehabilitation staff. The American College of Surgeons (ACS) has developed a verification process for trauma centers which establishes the capabilities of an institution to care for different levels of trauma (8).
A key feature of the ACS verification process is the need for system evaluation. A trauma system must be able to keep accurate data on its own performance and establish thresholds for key features of patient management. Changes in the system should be driven by the quality improvement program and adequate data should be gathered to assess the impact on patient outcomes of changes to the system.
Another important component of the ACS process is the carefully prescribed hierarchy of the trauma team composition and the designation of the trauma surgeon as the team leader and focus. Facility requirements, credentialing requirements, and the quality improvement process are also carefully spelled out. The verification process includes a paper review as well as an on-site visit with chart reviews and interviews.
Like trauma systems, processes for the improvement of care to patients suffering acute myocardial infarction (AMI) have led to improvements in care and decreases in mortality (9). The advent of thrombolytic treatment and angioplasty requires teamwork and an efficient system for patient evaluation and entry into treatment protocols.
AMI is the leading cause of death in the United States (10). Although death rates have declined by 54% since 1963, almost 500,000 people will die each year in the United States from AMI. Acute mortality and long-term morbidity are determined largely by the extent to which the myocardium is damaged by the AMI (11). There are two main reasons for advocating early arrival and treatment for AMI: (a) most AMI deaths will occur within the first hour after symptom onset and are due to cardiac dysrhythmias, and (b) early treatment with thrombolytic therapy will decrease mortality (12-14).
The greatest reduction in mortality is achieved in patients who are treated within 1 hour of symptom onset (15,16). In one trial, patients receiving treatment within 1 hour had a mortality of 1.3% compared with 8.7% in patients treated later (9). In 1991, the National Heart, Lung, and Blood Institute launched the National Heart Attack Alert Program (NHAAP) to promote rapid identification and treatment of patients with AMI (17). The thrust of these efforts was to reduce morbidity and mortality from AMI. The program sought to reduce the time from symptom onset to treatment into identifiable time phases and to analyze each phase in detail. These phases include patient/bystander factors (those that delay recognition and access to care), prehospital factors (those that occur from the time medical care is accessed to arrival at the hospital), and hospital factors (those that delay treatment after arrival at the hospital).
In distinction to the development of trauma systems where the system is prescribed in detail and the results of the system are measured and analyzed, the NHAAP identified a set of goals for treatment without specifying in detail how those goals should be reached in an individual institution. The NHAAP identified a time of 60 minutes from symptom onset to treatment as the goal for programs designed to reduce mortality from AMI. The time from ED arrival to treatment should ideally be 30 minutes or less. Suggestions were made for ways to realize these goals but the achievement of the goals is the main endpoint rather than the formation of the system.
Acute medical care in the United States is at its best when managing patients with major trauma or AMI. In developing systems for acute stroke treatment, important lessons can be learned from an in-depth analysis of the procedures and systems for treatment of AMI and trauma victims. It is unlikely that either system will be utilized in exactly the same way for stroke treatment, but we hope the end results of decreased morbidity and mortality will be achieved.
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National Institute of Neurological Disorders and Stroke
National Institutes of Health
Bethesda, MD 20892
Last updated May 17, 2011