Emergency Medical Services: Overview and Ground Transport

Emergency Medical Service Systems

Multiple EMS system designs exist, all predicated on the type of community served. Whereas this is a local decision, all states incorporate an administrative office that governs or oversees the provision of EMS activities. The role of the state office includes planning, licensing services and providers, and establishing or enforcing the scope and standards of practice. Other functions may include disaster preparedness and response activities, public health initiatives, record keeping, data collection, and auditing or investigating programs or providers. A description of EMS systems for the 200 most populous cities in the United States is periodically published in the Journal of Emergency Medical Services. For simplicity, the following categorization of systems is used: private and public agencies; basic life support (BLS) and advanced life support (ALS) services; and single-tiered, multitiered, and first responder systems.

Private and Public Agencies

Where local government has not assumed primary responsibility for EMS services, communities may depend on private providers. Financial responsibility varies but usually depends on federal reimbursement (Medicare or Medicaid) and user fees. A local government subsidy may or may not supplement the operation. If multiple providers are serving one jurisdiction, calls may be allocated by rotation or specified zone coverage. Dispatching varies by system but may be by the provider or by a central agency. Medical direction is often provided by a contracted physician or physician oversight board.

Hospital-based EMS systems are few in number and may be managed by a single hospital or hospital corporation. Not all hospital-based EMS programs are considered private, in that the hospital may be a division under local or state government or operate under a public authority. Financial responsibilities and dispatching are similar to private models outlined previously. An emergency physician from a sponsor or base hospital typically provides medical direction.

A public utility model is a hybrid between private and public design that allows local government to contract with a private or public provider. The service selected, usually through a request for proposal and competitive bidding process, becomes a contracted entity that agrees to provide the specified services (ALS, BLS, or both) and, depending on the arrangement, bills the patient directly or receives uniform reimbursement. A subsidy may or may not be provided by the local jurisdiction, dispatching may be performed by an existing public safety organization or by the parent company, and medical direction is usually performed by a specified individual subject to contractual terms.

When municipal governments were faced with planning and establishing EMS systems, many decided that fire departments would be well-equipped to provide EMS in addition to fire services. Fire stations are strategically located throughout the community and personnel are already used to providing emergency response and public services. Firefighters can be cross-trained as firefighters-paramedics or dedicated to performing either fire or EMS functions separately. Public EMS systems that were not incorporated into fire departments evolved into their own separate entity, referred to as a municipal third-service system . Such agencies are endorsed and supported by local government. Many cities have been successful in combining police, fire, and EMS under a global public safety agency, with all department heads or chiefs reporting to one administrator. Financially, public EMS systems may be supported by a per-capita tax base, which may or may not be supplemented by user fees. Regardless of design, medical oversight for a municipal EMS system may be provided by a physician appointed and contracted by the municipality, a local hospital, an advisory council or medical society, or a medical oversight board.

Basic Life Support and Advanced Life Support Service

Basic life support describes the provision of emergency care without the use of advanced therapeutic interventions. Skills include airway management (oral and nasal airways, bag-mask ventilation, extraglottic airways), cardiopulmonary resuscitation (CPR), hemorrhage control, fracture and spine immobilization, and childbirth assistance. Defibrillation with an automated external defibrillator (AED) is often included by many BLS systems. Services are provided by emergency medical responders (EMRs) or emergency medical technicians (EMTs), and medical direction may or may not be a requirement depending on individual state regulations. Few urban communities across the United States operate solely at the BLS level. Many rural and some suburban EMS services rely on volunteers who may not wish to become advanced-level providers. Because these services may have low call volumes, it becomes difficult for personnel to maintain advanced skills. Also, such communities may not have access to medical supervision or hospital sponsorship for ALS care.

The effectiveness of ALS for medical and traumatic emergencies is debatable, although systems categorized as ALS offer a more comprehensive level of service by highly educated providers, usually certified at the advanced emergency medical technician (AEMT) or paramedic level. Provider skills include advanced airway interventions, intravenous line placement, medication administration, cardiac monitoring and 12-lead electrocardiographic (ECG) interpretation, and certain invasive procedures.

Most EMS systems in cities operate at this level of care; however, the number of paramedics in any jurisdiction has come under scrutiny, in that cities with more paramedics per capita tend to have lower survival rates. Although this may seem counterintuitive, one explanation might be that the number of patient encounters per paramedic decreases and skill performance degrades when more providers are competing for the same number of experiences.

Single-Tiered, Multitiered, and First Responder Systems

In a single-tiered system, every response regardless of call type receives the same level of personnel expertise and equipment allocation (all BLS or ALS). Multiple-tiered systems use a combination of ALS and BLS levels, depending on the nature and potential severity of the call. Differences in cost and effectiveness between a mixed ALS-BLS service and an all-ALS service have been debated. A single-tiered ALS response may prove to be cost-effective in specific locales, ensures the capability of providing a consistent advanced level of care to all patients regardless of illness or injury severity, and obviates the potential for undertriage or overtriage by 911 telecommunicators. Alternatively, a multitiered system may meet the needs of individual communities and could be less costly because EMTs are usually compensated less than paramedics. This design also has the potential to preserve ALS resources for higher priority calls.

Regardless of single- or multiple-tier design, EMS systems usually include first responder services as part of their structure. The first responder, usually a police officer or firefighter, is the nontransport BLS or ALS provider who responds to the scene of an emergency to provide initial care before definitive medical care and transportation assets arrive. The first responder quickly assesses the scene and patients, determines whether additional resources are required, initiates patient care, and provides information to responding personnel prior to their arrival.

The design of an EMS system is targeted toward providing quality patient care in the briefest time after unexpected injury or illness. A desirable and cost-effective design might include BLS nontransport first responders with short response times (average 2 to 4 minutes) having the capability of providing early defibrillation and airway support, coupled with ensuing ALS care and transport services.

Emergency Medical Responder

The EMR, formerly referred to as medical first responder, is typically the first to arrive on the scene of an incident. Initial scene and patient assessment along with limited lifesaving interventions is the primary function. Along with CPR and basic airway management skills, the EMR should be able to control hemorrhage, manually secure an airway, stabilize fractures, perform CPR, and operate an automatic external defibrillator (AED). The EMR also assists the EMT or paramedic with ongoing care following their arrival.

Emergency Medical Technician

The EMT, formerly referred to as the EMT-Basic, is the minimum level required to staff an ambulance and is commonly used for nonemergency and convalescent transport services or paired with a higher-level provider for ALS care. In addition to the skills of the EMR, the EMT is also involved with triage, more detailed patient assessment, and transportation.

Many but not all states have expanded the EMT scope of practice to include extraglottic airway insertion; use of continuous positive airway pressure; epinephrine administration for anaphylaxis, naloxone, chemical nerve agent antidote autoinjections; and administration of aspirin, nitroglycerin, and albuterol by handheld nebulizer or metered-dose inhaler.

Advanced Emergency Medical Technician

The AEMT, formerly referred to as the EMT-Intermediate, was established to allow a more comprehensive approach to care when paramedic services are unavailable or unobtainable due to a limited workforce. Many states recognize the AEMT certification, but others designate alternative but comparable levels depending on specific skills and procedures. This level is useful for rural systems because it provides some ALS care for less cost and education time. The scope of practice for the AEMT varies across the United States. In addition to all EMT skills, most systems allow the AEMT to establish an intravenous line, to manually defibrillate, and to administer limited medications.

Paramedic

Paramedics are the most advanced prehospital providers. Their scope of practice includes a wide variety of therapeutics and procedures including 12-lead ECG rhythm interpretation, expanded pharmacologic treatments, and advanced airway interventions. Invasive and lifesaving procedures include needle decompression of a tension pneumothorax, needle or surgical cricothyrotomy, and transthoracic cardiac pacing.

Initial training courses for all levels of providers include didactic, clinical, and field education, each escalating in complexity for higher levels of certification and all focusing on technical and professional competencies. Additional coursework programs exist for paramedics that expand the scope of practice, including the flight paramedic for fixed or rotor wing services, the community paramedic who serves in a population health capacity, and the critical care paramedic for high-risk adult and pediatric transfers. With the expansion of EMS technology and management career options, many paramedic educational programs have advanced from 1-year certificate curricula to 2-year associate or 4-year baccalaureate degrees. Since 2018, as a means to ensure quality prehospital education and consistency, any individual applying for national paramedic certification must have graduated from a program accredited by the Commission on Accreditation of Allied Health Education Programs.

In keeping with the spirit of the EMS Agenda for the Future, which specifically calls for integration of health services and prevention attributes, some systems have implemented programs that engage interprofessional health providers into the existing structures of care. Examples include embedding a nurse triage system at the 911 access level, where low-acuity complaints as determined by evidence-based algorithms are transferred to alternative call centers. Here, nurses determine and arrange appropriate care at a clinic or facility other than an emergency department (ED). Another example that is becoming popular is having prehospital providers, usually at the paramedic level, provide patient evaluation services to pre-identified patients with chronic conditions such as hypertension, diabetes, congestive heart failure, and substance abuse. These programs, referred to as community paramedics, mobile integrated health, or advanced practice paramedics , among others, often include interprofessional providers (nurses, social workers, case managers), and are designed to prevent or reduce the need for EMS calls and decrease ED utilization for targeted patients or frequent users.