AVPU

The AVPU scale (an acronym from "alert, verbal, pain, unresponsive") is a system by which a health care professional can measure and record a patient's level of consciousness. It is mostly used in emergency medicine protocols, and within first aid.
It is a simplification of the Glasgow Coma Scale, which assesses a patient response in three measures: eyes, voice and motor skills. The AVPU scale should be assessed using these three identifiable traits, looking for the best response of each.
Meaning of the mnemonic.
The AVPU scale has four possible outcomes for recording (as opposed to the 13 possible outcomes on the Glasgow Coma Scale). The assessor should always work from best (A) to worst (U) to avoid unnecessary tests on patients who are clearly conscious. The four possible recordable outcomes are:
In first aid, an AVPU score of anything less than A is often considered an indication to get further help, as the patient is likely to be in need of more definitive care. In the hospital or long term healthcare facilities, caregivers may consider an AVPU score of less than A to be the patient's normal baseline.
In some emergency medical services protocols, "Alert" can be subdivided into a scale of 1 to 4, in which 1, 2, 3 and 4 correspond to certain attributes, such as time, person, place, and event. For example, a fully alert patient might be considered "alert and oriented x 4" if they could correctly identify the time, their name, their location, and the event.
EMS crews may begin with an AVPU assessment, to be followed by a GCS assessment if the AVPU score is below "A."
The AVPU scale is not suitable for long-term neurological observation of the patient; in this situation, the Glasgow Coma Scale is more appropriate.
Limitations.
As mentioned above, it should not be used for long-term follow up of neurological status.
Comparison with other classification systems.
When compared to the Glasgow Coma Scale (GCS) the AVPU classification of alertness has been suggested to correspond in the following manner: 