Modern EMS systems developed following the 1966 publication of a National Academy of Sciences paper entitled Accidental Death and Disability: The Neglected Disease of Modern Society29 and the work of J.F. Pantridge extending emergency cardiac care to the prehospital setting in the United Kingdom.30 Dr. Pantridge’s program in Northern Ireland inspired the pioneering efforts of physicians such as Eugene Nagel in Miami and Leonard Cobb in Seattle to extend emergency cardiac care to the patient’s home.31,32
Federal Involvement in EMS Begins
Accidental Death and Disability called for improving prehospital trauma care.29 As a result, Congress passed the Highway Safety Act in 1966, which established the National Highway Traffic Safety Administration (NHTSA) within the Department of Transportation. Because motor vehicle crash injuries constituted a substantial proportion of the EMS patient load, NHTSA was charged with improving EMS systems by administering grants for ambulance purchases, communications systems, and training programs, and with supporting other traffic related system improvements. NHTSA furthered its role in the advancement of prehospital care by developing national standard curricula for the education of EMS personnel and by lending its foresight, leadership, and commitment to the development of EMS systems.
In 1973, Congress enacted the EMS Systems Act (Public Law 93-154). This Act provided funding for the development of regional EMS systems and authorized a program of research in emergency techniques, methods, devices and delivery. The National Center for Health Services Research (NCHSR), predecessor to the Agency for Healthcare Research and Quality (AHRQ), was responsible for administering this applied research effort. Between 1974 and 1981, the NCHSR supported approximately 50 EMS demonstration projects.
In 1984, Congress established the federal EMS for Children (EMSC) program as a demonstration grant co-sponsored by NHTSA and housed in the Maternal and Child Health Bureau. The Institute of Medicine issued a 1993 report on EMS for children that identified several priority areas, including a call for additional data collection, evaluation and research.4 Since the report was issued, the EMSC program has played a valuable part in advancing the cause of EMS research and in establishing directions for the future of EMS for children. In addition to providing funding and leading EMS initiatives, the program has developed a consensus document of research priorities, including identifying appropriate outcomes.33
In January 2001, seven federal agencies participated on an interagency program announcement, PA-01-044, titled Emergency Medical Services for Children Research. The topics to be studied include asthma, traumatic brain injury, and violence prevention. HRSA’s other federal partners in this effort (besides the Agency for Healthcare Research and Quality) were the National Institute for Occupational Safety and Health at the Centers for Disease Control and Prevention, as well as the National Heart, Lung and Blood Institute, National Institute for Child Health and Human Development, National Institute on Drug Abuse, National Institute of Mental Health, and the National Institute of Nursing Research, all from the National Institutes of Health.
Other EMSC initiatives providing funding for EMS research include the support of the development of a National EMS Database jointly with NHTSA, awards to promote pediatric patient safety research in EMS, and the EMSC Network Development Demonstration Project (NDDP) Cooperative Agreement Grant (CDA#93.127L). The $1.8 million NDDP grant is being supported by the EMSC program in collaboration with the Division of the Research, Training and Education of the Maternal and Child Health Bureau. NDDP will support the best proposals to create research networks for performing high quality collaborative research on EMSC topics. Each research node will collect data from participating EDs in its area in order to get answers to pediatric emergency care research questions which were previously difficult to obtain.
Beginning of EMS Research
During the late 1960’s, a growing number of EMS organizations around the world recognized that their ambulance services required advancement.34-38 Improvements in these systems were generally implemented without undergoing unbiased evaluation. For example, in 1966 an editorial in the British Medical Journal suggested that patients were dying of suffocation because ambulance service personnel were inadequately trained in airway management.34 EMS systems responded by introducing airway interventions formerly reserved for the hospital emergency department directly into the field setting. The prevailing attitude was that if an intervention was useful and effective in the hospital then it would be similarly useful in the prehospital environment.
However, study results from one particular environment do not necessarily translate successfully to other environments and may not apply to other populations. Studies of efficacy (i.e., does something work under ideal conditions) do not necessarily indicate effectiveness (i.e., does it work in the real world). Interventions that work in the emergency department might not work in the ambulance, interventions that work in an ambulance might not work in a helicopter, and interventions that work in a moderately busy suburban EMS system may not work in an overburdened urban system. While it makes intuitive sense to take the emergency department to the patient, the compressed time frame for patient evaluation, the lack of many medical technologies such as x-rays, and the limited training of EMS professionals sometimes alter the risk-benefit ratio.39
The earliest scientific analyses of EMS practices were limited in scope and methodology. Only three EMS-related randomized, controlled clinical trials were published before 1980.40-42 The remaining published studies were observational, descriptive, or retrospective in nature. Many studies were designed simply to demonstrate that certain hospital interventions, such as inserting a peripheral intravenous line or performing defibrillation, could be extended to the prehospital environment.30,43 Often the results indicated that the intervention could be applied in the field but gave no clue as to whether the patient benefited. For example, the early studies of the pneumatic anti-shock garment (PASG) and the esophageal obturator airway (EOA) observed physiologic responses such as increased blood pressure but did not evaluate the relationship of the physiologic changes to patient outcome.44,45
The science of EMS has been criticized for providing insufficient evidence to support many of its practices. In 1989, Ronald Stewart advised that EMS must begin to prove itself through research.46 Nearly a decade later, Michael Callaham repeated the sentiment and observed, “It is possible to document exactly how much scientific support there is for the efficacy of our present scope of EMS practice, and it is impressively deficient.”27
Progress towards a scientific foundation for EMS practices is slow, in part due to the inherent difficulties in performing research in the field, but also because of the lack of research infrastructure in EMS systems and the absence of funded researchers working in this field. Thousands of people dedicated to improving prehospital care including physicians from a variety of specialties, EMS providers, allied health professionals, public leaders, and even the lay public have been working both individually and through myriad professional organizations toward creating that scientific basis. Most research accomplished to date within EMS has been conducted on shoestring budgets using volunteer labor, surplus supplies, and in kind contributions from hospitals, medical schools, and EMS agencies.
A Case Study
In EMS Research
The experience with the pneumatic anti-shock garment (PASG) is illustrative of the early research experience in EMS. Many EMS physicians promoted its use in a wide variety of medical and surgical conditions with little evaluation of its effectiveness,47,48 while others were less convinced of its value.49 PASG use became widespread, with many jurisdictions requiring them as minimal equipment for ambulances at an expense of several thousand dollars per vehicle. Several years after gaining acceptance as a standard item to be stocked on ambulances, a single, randomized clinical trial found that application of the PASG to victims of truncal penetrating trauma in an urban environment actually worsened patient outcome.50 In the wake of that study, the popular sentiment rapidly shifted to renounce the use of the PASG. Yet, a comprehensive review of the literature established that some patients might in fact benefit from use of the PASG.17 This is but one example in which misinformation and the lack of scientific knowledge about optimal patient care has confused clinicians and left them floundering to provide the best care without the guidance of good science.
Decisions about the effectiveness of any intervention must be based upon reliable evidence. This requires that there be enough studies to provide sufficient information upon which, among other things, effectiveness and generalizability of the intervention can be determined. Due to the paucity of available research, EMS decision makers have been forced to make judgments based upon limited evidence. Two current issues in which this problem is readily apparent are pediatric airway management, where one controlled trial has questioned the efficacy of endotracheal intubation;18 and the use of amiodarone for cardiac arrest, where another randomized controlled trial has suggested a positive effect.51 While both of these studies are examples of methodologically sound research and add to the overall understanding of their respective issues, additional high quality investigations are needed.
