Strategies for delivering care

Although a variety of differing philosophical approaches are used in the provision of EMS care around the world, they can generally be placed into one of two categories; one physician-led and the other led by pre-hospital allied health staff such as emergency medical technicians or paramedics. These models are commonly referred to as the Franco-German model and Anglo-American model.

Studies have been inconclusive as to whether one model delivers better results than the other. A 2010 study in the Oman Medical Journal suggested that rapid transport was a better strategy for trauma cases, while stabilization at the scene was a better strategy for cardiac arrests.

Levels of careedit

Many systems have tiers of response for medical emergencies. For example, a common arrangement in the United States is that fire engines or volunteers are sent to provide a rapid initial response to a medical emergency, while an ambulance is sent to provide advanced treatment and transport the patient. In France, fire service and private company ambulances provide basic care, while hospital-based ambulances with physicians on board provide advanced care. In many countries, an air ambulance provides a higher level of care than a regular ambulance.

Examples of level of care include:

• First aid consists of basic skills that are commonly taught to members of the public, such as cardiopulmonary resuscitation, bandaging wounds and saving someone from choking.
• Basic Life Support (BLS) is often the lowest level of training that can be held by those who treat patients on an ambulance. Commonly, it includes administering oxygen therapy, some drugs and a few invasive treatments. BLS personnel may either operate a BLS ambulance on their own, or assist a higher qualified crewmate on an ALS ambulance. In English-speaking countries, BLS ambulance crew are known as emergency medical technicians or emergency care assistants.
• Intermediate Life Support (ILS), also known as Limited Advanced Life Support (LALS), is positioned between BLS and ALS but is less common than both. It is commonly a BLS provider with a moderately expanded skill set, but where it is present it usually replaces BLS.
• Advanced Life Support (ALS) has a considerably expanded range of skills such as intravenous therapy, cricothyrotomy and interpreting an electrocardiogram. The scope of this higher tier response varies considerably by country. Paramedics commonly provide ALS, but some countries require it to be a higher level of care and instead employ physicians in this role.
• Critical Care Transport (CCT), also known as medical retrieval or rendez vous MICU protocol in some countries (Australia, NZ, Great Britain, and Francophone Canada) refers to the critical care transport of patients between hospitals (as opposed to pre-hospital). Such services are a key element in regionalized systems of hospital care where intensive care services are centralized to a few specialist hospitals. An example of this is the Emergency Medical Retrieval Service in Scotland. This level of care is likely to involve traditional healthcare professionals (in addition to or instead of critical care-trained paramedics), meaning nurses and/or physicians working in the pre-hospital setting and even on ambulances.

Transport-onlyedit

The most basic emergency medical services are provided as a transport operation only, simply to take patients from their location to the nearest medical treatment. This was historically the case in all countries. It remains the case in much of the developing world, where operators as diverse as taxi drivers and undertakers may transport people to hospital.

Transport-centered EMSedit

The Anglo-American model is also known as "load and go" or "scoop and run". In this model, ambulances are staffed by paramedics and/or emergency medical technicians. They have specialized medical training, but not to the same level as a physician. In this model it is rare to find a physician actually working routinely in ambulances, although they may be deployed to major or complex cases. The physicians who work in EMS provide oversight for the work of the ambulance crews. This may include off-line medical control, where they devise protocols or 'standing orders' (procedures for treatment). This may also include on-line medical control, in which the physician is contacted to provide advice and authorization for various medical interventions.

In some cases, such as in the UK, South Africa and Australia, a paramedic may be an autonomous health care professional, and does not require the permission of a physician to administer interventions or medications from an agreed list, and can perform roles such as suturing or prescribing medication to the patient. Recently "Telemedicine" has been making an appearance in ambulances. Similar to online medical control, this practice allows paramedics to remotely transmit data such as vital signs and 12 and 15 lead ECGs to the hospital from the field. This allows the emergency department to prepare to treat patients prior to their arrival. This is allowing lower level providers (Such as EMT-B) in the United States to utilize these advanced technologies and have the doctor interpret them, thus bringing rapid identification of rhythms to areas where paramedics are stretched thin.

Major traumaedit

The essential decision in prehospital care is whether the patient should be immediately taken to the hospital, or advanced care resources are taken to the patient where they lie. The "scoop and run" approach is exemplified by the MEDEVAC aeromedical evacuation helicopter, whereas the "stay and play" is exemplified by the French and Belgian SMUR emergency mobile resuscitation unit or the German "Notarzt"-System (preclinical emergency physician).

The strategy developed for prehospital trauma care in North America is based on the Golden Hour theory, i.e., that a trauma victim's best chance for survival is in an operating room, with the goal of having the patient in surgery within an hour of the traumatic event. This appears to be true in cases of internal bleeding, especially penetrating trauma such as gunshot or stab wounds. Thus, minimal time is spent providing prehospital care (spine immobilization; "ABCs", i.e. ensure airway, breathing and circulation; external bleeding control; endotracheal intubation) and the victim is transported as fast as possible to a trauma centre.

The aim in "Scoop and Run" treatment is generally to transport the patient within ten minutes of arrival, hence the birth of the phrase, "the platinum ten minutes" (in addition to the "golden hour"), now commonly used in EMT training programs. The "Scoop and Run" is a method developed to deal with trauma, rather than strictly medical situations (e.g. cardiac or respiratory emergencies), however, this may be changing. Increasingly, research into the management of S-T segment elevation myocardial infarctions (STEMI) occurring outside of the hospital, or even inside community hospitals without their own PCI labs, suggests that time to treatment is a clinically significant factor in heart attacks, and that trauma patients may not be the only patients for whom 'load and go' is clinically appropriate. In such conditions, the gold standard is the door to balloon time. The longer the time interval, the greater the damage to the myocardium, and the poorer the long-term prognosis for the patient. Current research in Canada has suggested that door to balloon times are significantly lower when appropriate patients are identified by paramedics in the field, instead of the emergency room, and then transported directly to a waiting PCI lab. The STEMI program has reduced STEMI deaths in the Ottawa region by 50 per cent. In a related program in Toronto, EMS has begun to use a procedure of 'rescuing' STEMI patients from the Emergency Rooms of hospitals without PCI labs, and transporting them, on an emergency basis, to waiting PCI labs in other hospitals.

Physician-led EMSedit

Physician-led EMS is also known as the Franco-German model, "stay and play", "stay and stabilize" or "delay and treat". In a physician-led system, doctors respond directly to all major emergencies requiring more than simple first aid. The physicians will attempt to treat casualties at the scene and will only transport them to hospital if it is deemed necessary. If patients are transported to hospital, they are more likely to go straight to a ward rather than to an emergency department. Countries that use this model include Austria, France, Belgium, Luxembourg, Italy, Spain, Brazil and Chile.

In some cases in this model, such as France, there is no direct equivalent to a paramedic. Physicians and (in some cases) nurses provide all medical interventions for the patient. Other ambulance personnel are not non-medically trained and only provide driving and heavy lifting. In other applications of this model, as in Germany, a paramedic equivalent does exist, but is an assistant to the physician with a restricted scope of practice. They are only permitted to perform Advanced Life Support (ALS) procedures if authorized by the physician, or in cases of immediate life-threatening conditions. Ambulances in this model tend to be better equipped with more advanced medical devices, in essence, bringing the emergency department to the patient. High-speed transport to hospitals is considered, in most cases, to be unnecessarily unsafe, and the preference is to remain and provide definitive care to the patient until they are medically stable, and then accomplish transport. In this model, the physician and nurse may actually staff an ambulance along with a driver, or may staff a rapid response vehicle instead of an ambulance, providing medical support to multiple ambulances.