Emergency medical dispatch
Medical Aid Calls
The Medical Priority Dispatch System (MPDS) is a medically-approved, unified system used to
dispatch appropriate aid to medical emergencies including systematized caller interrogation
and pre-arrival instructions. MPDS starts with the dispatcher asking the caller key questions.
These questions allow the dispatchers to categorize the call by chief complaint and set a
determinant level ranging from A (minor) to E (immediately life threatening) relating to the
severity of the patient’s condition.
Each call is also assigned a sub-category or code, often used as a means of gathering
further statistics about performance. It also helps when analyzing the calls for how the call
was described by the informant, compared to the injury or illness found when the crew
attends. This can then be used to help improve the questioning system which gives the MPDS
classification. Each category is numbered from 1 (abdominal pain) through 32 (unknown).
This is usually used for brevity and privacy over the radio.
Letter
Severity
Resources
Non Life-Threatening
Basic Life Support
Non-Emergency
Alpha 21%
Response
Alpha
Echo 2%
Bravo
Possibly Life-Threatening
Basic Life Support
Emergency
Charlie
Life-Threatening
Advanced Life Support
Emergency
Delta
Serious Life Threat
Advanced Life Support
Emergency
Echo
Life Status Questionable
Closest Available
(Multiple Resources Sent)
Emergency
Delta 32%
Bravo 23%
Charlie 22%