An air ambulance is just what it sounds as though it is: a medical transport that takes place in the air. It is generally characterized by a helicopter that rescues individuals with medical emergencies and evacuates them to medical centers for treatment. Depending on the nature of the emergency, however, an air ambulance might also be a large plane, used to move patients with sensitive medical conditions.
There are two types of air ambulances: those simply responsible for transporting patients without the ability to care for them on board; and those that have been retrofitted for patient care. Crews on air ambulances with the purpose of on-board patient care are generally certified emergency medical technicians and may sometimes be comprised of a crew of doctors and nurses trained in this type of transitional care. This is key because many air ambulance patients are often critically injured or ill and need immediate care until they are able to make it to a medical facility. They may need access to specialized equipment and medications, including heart monitoring units, stretches, ventilators, pain medication and more.
The proper military term for the distinction between the two is a medical evacuation - or MEDEVAC - for those air ambulances that treat patients in the air and a casualty evacuation - or CASEVAC - which simply moves patients to a place for proper treatment. This particular mode of transport may be operated by a private medical facility and dispatched in conjunction with a local authority in charge of handling calls for medical emergencies. Private companies also own fleets used for this purpose, and contract with medical facilities to reach patients in critical care situations. Businesses may also donate funds or actual planes/copters for the use of medical transport.
In many instances, access to an air ambulance - whether just for transport or for treatment while on the move - can be the difference between life and death. Critical care situations that necessitate such a mode of transport might include a heart attack or stroke, animal bite (particularly a snake bite), a fall where swelling of the brain might be an issue, a spinal or neck injury or internal bleeding, all of which often need surgery in a timely manner to reverse course of the injury.
An air ambulance can often get to places a traditional ambulance cannot, including rural areas, natural settings where people might be hiking or camping or even busy highways, where snarled up traffic can hold up a traditional ambulance for hours. Crews must undergo training to gain access to remote areas and places where landing an air ambulance can be tricky, such as in the case of landing on a busy highway to access someone in need of medical treatment.
There are certainly risks to operating and utilizing this mode of transport, including the possibility of a crash (which also exists for a traditional ambulance) and the constant jostling of the patient, due to uncontrollable issues when in the air (think turbulence and things of that nature). Staff has to work quickly to secure patients, which can be tricky when there are limited supplies and space in which to work. Most medical staffs on board an air ambulance are simply charged with stabilizing the patients to whatever degree possible in order to get them to the facility, where doctors can then go to work on them.
However, air ambulances are generally a part of every major medical facility's operation because of the access they offer to patients that desperately need care. While they can be a major expense for a facility, they also save lives, which is the benefit of having this type of fleet.