The core principle of triage is to do the most for the most. The initial triage method in a multiple casualty situation is the triage sieve. Triage sieves can be applied to either adults or children.

At the point when it has been identified that multiple casualties will require treatment, the fire control room should be notified so that the required resources can be mobilised. It may be appropriate to declare a major incident using the JESIP M/ETHANE model.

The triage sieve will identify immediately life-threatening problems based on the C < A B C > system, and correctly prioritise casualties for treatment. Not doing this will potentially risk lives.

Fire and rescue services should be prepared to employ triage sieves if there are multiple casualties or at a major incident.

As a principle, at a poorly resourced incident, minimal casualty care is provided if there are multiple casualties. The following actions can be achieved without breaching the core principle of triage:

• Quickly turn a casualty to protect their airway
• Encourage self-help
• Encourage a bystander to apply direct pressure

The Ambulance Clinical Practice Guidelines (JRCALC) acknowledge that now ambulance services are all practising C < A B C > in their initial patient assessment, the standard triage sieve needs to take account of the importance of initial assessment and treatment of catastrophic haemorrhage.

The diagram below is the National Ambulance Resilience Unit (NARU) Triage Sieve, which was published for use by all ambulance staff at a major incident.

The priorities are described as:

• P1 or red tags (immediate) are used to label those who cannot survive without immediate treatment but who have a chance of survival
• P2 or yellow tags (observation) are for those who require observation (and possible later re- triage). Their condition is stable for the moment and they are not in immediate danger of death. These casualties will still need hospital care and would be treated immediately under normal circumstances.
• P3 or green tags (wait) are reserved for the 'walking wounded' who will need medical care at some point, after more critical injuries have been treated.

The JESIP casualty triage has an additional priority:

• P4 or P1E (expectant) is used for those whose injuries are so extensive that they will not be able to survive given the care or resource that is available. This is only to be used under authorisation of the Medical Incident Officer. They alone have the responsibility to match these casualties’ injuries with the number and type of the other casualties and the remaining resources available to the hospitals.

The same triage principles apply to children. Paediatric triage tape is available, which groups children by length, weight and age and provides normal physiological values for respiratory rate and pulse in each of the groups to carry out the triage process.

Having labelled the casualty with their priority, casualties are handed over to medical responders. A record or log of the numbers of each priority should be kept and the fire control room notified.

When referring to casualties and the above priorities at the scene of an incident, everyone should be sensitive to those who could overhear the information; this could include relatives, members of the public or the media.