Advanced Medical Priority Dispatch System

Star of Life

The Advanced Medical Priority Dispatch System (AMPDS), is a medically-approved, unified system used to dispatch appropriate aid to medical emergencies including systematized caller interrogation and pre-arrival instructions. AMPDS is developed and marketed by Priority Dispatch Corporation which also has similar products for police and fire.

The output gives a main response category - A (Immediately Life Threatening), B (Urgent Call), C (Routine Call). This may well be linked to a performance targeting system such as ORCON where calls must be responded to within a given time period. For example, in the United Kingdom, calls rated as 'A' on AMPDS are targeted with getting a responder on scene within 8 minutes.

Each call is then assigned a sub-category or code, often used as a means of gathering statistics about performance. It also helps when analysing the calls for how the call was described by the informant, compared to the injury or illness found when the crew attend. This can then be used to help improve the questioning system which gives the AMPDS classification.

It should be noted that each category is also referred to by a number from 1 (abdominal pain) through 32 (unknown). This is usually used for brevity and privacy over the radio. In some areas instead of the A, B, C categories, A (alpha) through E (echo) are used.

The software is used widely but its validity is constantly questioned by first reponders in the pre hospital care environment. It is often accused of responding emergency vehicles under fast lights and siren situations for no good reason. The cause of this falling on questions asked to callers that are deliberately kept simple to avoid confusion. For example, call takers ask callers if the "patient is breathing normally" rather than is "the patient is having difficulty breathing" which is considered too technical. Consequently, a patient who is nauseated and vomiting may be considered to be having difficulty breathing as the caller notices that the patient is breathing differently from normal when vomiting. Breathing whilst vomiting does often appear different from normal breathing. This does not mean the patient is having difficulty breathing. The result is an ambulance dispatced under emergency driving conditions that creates an increased risk of accident and potential harm to responding paramedics and the community alike regardless of the care taken whilst driving. An experienced paramedic taking a call would be able to differentiate between the breathing differences of someone vomiting and someone who truly is having trouble breathing. For cost effectivness AMPDS does not generally use medically qualified and experienced call takers. It uses call takers trained to use the software rather than those experienced in the pre hospital care environment. This is a major and on going criticism of the AMPDS software.

References

• United Kingdom Department of Health - AMPDS Call Categorisation Version 11. Her Majesty's Stationery Office. April 2005