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Triage of multiple casualties

Triage (sorting) is needed when the immediate demands exceed the available resources.

The aim of the triage sieve is to identify as rapidly as possible those patients/casualties who require care most urgently.

If there are more casualties than people to care for them, triage must be carried out before starting treatment.

Remember the casualty shouting the most may be the most physiologically intact - worry about the casualties who are making no noise.

The triage methods below are used in the UK. Other approaches are used elsewhere, though the aim is consistent.

Whichever triage system is used it is vital to remember that triage is a dynamic process - being repeated as casualties are moved, their condition changes or the availability of resources alters.

Triage is a difficult task, and should be carried out by the most senior/experienced personnel possible (one rule of thumb is for the most experienced clinician to take overall charge and for the next most senior clinician to carry out triage).

The Triage Sieve

Is used in incidents with multiple casualties.
Casualties must be triage before treatment - it is difficult for clinicians to move away from someone who is clearly badly injured.
Stop the assessment as soon as you are able to assign a triage category. Do not do the complete triage assessment on all casualties as this will slow down triage.
When triaging make a note of the number of casualties in each triage category. Do this as you are going along.

The triage categories are:
delayed [P3]

urgent [P2

immediate [P1]


It operates as follows:
1) Those who can mobilise independently are delayed [P3] (lowest priority).
Once other casualties have been assessed the P3 casualties should be reassessed as conditions do change.
Watch for ambulant casualties carrying other casualties (especially adults carrying their children); every casualty must be triaged.

2) In those who cannot walk determine if the casualty is breathing (done very quickly if the casualty can talk).
If there is no breathing ensure the airway is open (basic manoeuvres + adjuncts only).
- if breathing is absent still the casualty is treated as dead and no further resuscitation undertaken.
- if breathing does return after airway opening the casualty is immediate [P1](top priority); efforts should be made to ensure the airway remains patient: this must not delay the triage - get someone else to maintain airway position.
No further assessment is needed for triage in P1 patients .

3) In those who are breathing without the need for airway opening assess the respiratory rate.
If high ( more than 29) or low (less than 10) the casualty is immediate [P1].
No further assessment is needed for triage in P1 patients .

4) In those who are uncategorised so far assess the circulation
either by capillary refill (be aware this may be delayed by cold rather than by shock) or by the pulse rate.
If these are abnormal (more than 2 seconds, or HR more than 120/minute) the casualty is P1, if normal they are urgent [P2].

5) As soon as the casualty has been assigned a triage category further assessment stops,
and personnel carrying out triage move to the next casualty to triage them.
Treatment does not start until casualties have been triaged.

6) Casualties' triage category should be indicated on them,
so P1 casualties can be identified and treated first.

7) Personnel carrying out triage should maintain a record of the total number of casualties they triage and the numbers within each category.


NB the criteria for respiratory rate - 10 to 29 is OK
Some books/sites wrongly have 10 to 30

This is an alternative sieve. Although similar to most of the algorithm above it changes the "C" assessment to presence or absence of the radial pulse. Since this is the parameter used to determine whether or not to start IV fluids prehospital [at least in the UK] it makes sense to use it for triage too. It does not assess the ability of the casualty to mobilise independently but does include as assessment of "D".


The triage sort

This is a slightly longer assessment using the revised trauma score,
It generates a numerical value; the lower this is the more urgent the patient's management.

3 aspects of the patient's physiology are assessed in the RTS:
Glasgow Coma Score (15 point version)
Systolic BP
Respiratory Rate

TRTS score triage category
1-10 immediate
11 urgent
12 delayed

The triage assessment should be documented and should accompany the patient.





Expectant Category

(very) Occasionally resources are so overwhelmed that it is impossible to deal with all the immediate category casualties. In this situation a decision may be taken to subdivide this group into immediate and expectant. The immediate casualties remain the top priority for treatment and transport. The expectant category casualties are even more badly injured and are unlikely to survive even if treated promptly. Resources directed the them are less likely to yield benefit than if directed to immediate casualties.
The decision to use the expectant category is not one to be taken lightly. It is the responsibility of the most senior clinician to initiate its use.


Paper on critical appraisal of papers describing triage systems
Short video about triage in Rwanda
Presentation on triage from USA
Guidelines for field triage of injured patients

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