Where a mass casualty situation is present, a triage process will be used to triage patients. This may be described as red, amber, green – p1, p2, p3. Different services and areas may use different categories. There is also the addition of ‘Dead’ for patients who are deceased.
Depending on your area/trust will determine the criteria for certain categories. As a general sense, any patients who are in a poor state requiring immediate treatment, such as a catastrophic haemorrhage, will be classed as p1 or red. P2 or amber will be individuals who are injured, in a somewhat stable state, but are unable to remove themselves from the scene due to injury. P3 will be individuals who have minor injuries, or injuries but are stable, and are able to walk out of the scene to a CCP. Dead patients will be those who are deceased even after basic interventions.
As mentioned, this is just a general sense of the prioritising process of patients but there will be specific criteria for this, different in different trusts and countries around the world. There can also be different triage criteria for different situations such as CBRN (Chemical, Biological, Radiological, Nuclear).