A few of the terms commonly encountered when discussing aeromedical services are listed below. Some terms are used interchangeably and not exactly in accordance with the definitions proposed.

Evacuation of a patient from an acute setting to a health service facility such as a hospital. For example, evacuation from a road accident, mine site, small aboriginal community.

Transport of a patient from a health service facility to another. For example, transport of a patient from district hospital to regional hospital, or regional hospital to teaching hospital.

Often used to refer to evacuation of a patient by a medical team, sent out from a regional centre and returning to the same centre. In Western Australia, with its vast distances and highly centralised specialist medical services, it is often used just to denote transport of patients by a medical team, irrespective of their origin and destination. (Often a team is located in a rural centre but transports the patient to a metropolitan centre). May be a primary or secondary transport, by road, air or other means.

Transport of a patient by air. May be a primary or secondary transport. "Evacuation" is generally used to refer only to primary transport but it is often used to refer to both. Used interchangeably with air medical transport.

Transport of a patient by air. A change in terminology arising in the U.S. (supposedly to distinguish transport of patients by air, from the study of aviation and aerospace medicine). Sometimes used to refer to other medical requirements for air transport, for example, organ transport.

Evacuation of a patient using a clinic flight.

Used by RFDS to define transport of a patient from a location which does not have a hospital with inpatient facilities and attending medical practitioners. These are primary transport.

Used by RFDS to define transport of a patient from one hospital to another, where a hospital is defined as health service facility with an inpatient capacity and attending medical officers. These are secondary transport.

Transfer of a patient back to their referring hospital or home at the conclusion of treatment or for convalescence. (Normally only occurs on an opportunity basis). These are also secondary transport.

A patient being repatriated to their referring hospital or home.

A person carried on an aeromedical aircraft who does not require a stretcher or any continuing medical or nursing care during the trip. For example, a relative, a health professional or an ambulant person being carried on an opportunistic basis to attend a hospital or clinic service.

Used to refer to patients who do not warrant a specific air medical flight but who will be carried on an opportunity basis. (If transported, the flight is subsequently recorded as a Priority 3).

An indication of the urgency of a patient's transfer. RFDS air medical transports are currently coded using a national three-point numeric scale. Priority 1 & 2 are "Life-threatening emergency" and "Urgent medical transfer" respectively. Priority 3 is an elective (non-urgent) transfer.

An indication of the severity of a patient's condition. (Not necessarily the same as priority. A patient may be seriously ill but stable and have low urgency). RFDS air medical transports are currently coded using a national five-point scale.

Time interval from receipt of flight request to the initial departure of the aircraft. (Includes the time involved in obtaining clinical details, determining priority, equipment, aircraft and crew requirements, tasking flight, assembling crew, flight planning and departing.)

Time interval spent by the medical on the ground attending the patient at the referring location.

Where a patient who does not require or receive the full normal assessment, observation and treatment by RFDS staff on a properly equipped aircraft, is transferred on a clinic flight. Patients on such flights will be categorised as "clinic passengers".

Where a patient is transferred on a charter aircraft without the full normal assessment, observation and treatment by RFDS staff . Patients on such flights will be categorised as "charter passengers".

Where RFDS staff are used on a charter aircraft due to weather, distance or other operational reasons and provide the normal assessment, observation and treatment in flight which is duly recorded on an observation chart, the flight will be categorised as an "Evacuation" or "Interhospital transfer" as if done on an RFDS medical aircraft.

The physiological and clinical effects resulting form the reduced partial pressure of inspired oxygen at altitude.

The physiological and clinical effects resulting from the change in volume of gases occurring at altitude.

An aircraft system which maintains a higher cabin pressure (lower cabin altitude) in an aircraft in flight than that outside the aircraft. Used to minimise the effects of altitude on patients and crew. Pressurisation may be used to allow flights at much higher altitudes than in unpressurised aircraft, or to allow medical flights to maintain a sea level cabin altitude.

Pertaining to reduced pressure, such as at altitude.

Pertaining to increased pressure, such as in diving.