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Disaster Triage &
Mass Casualty Principles

Learn how nurses sort patients to do the greatest good for the greatest number when resources are limited.

NCLEX-RN

What Is Triage?

Triage is the process of sorting and prioritizing patients based on the severity of their condition and their likelihood of survival with available resources.

Two Different Contexts

Daily / ER Triage
Adequate resources. The sickest patient is seen first. Goal: best outcome for each individual.
Disaster / Mass Casualty
Demand exceeds resources. Care goes to those most likely to survive. Goal: maximize total survivors.

The Four Triage Colors

RED Immediate Life-threatening but survivable Priority 1 YELLOW Delayed Serious but can wait briefly Priority 2 GREEN Minor Walking wounded Priority 3 BLACK Expectant Deceased or unsurvivable Priority 4

The Core Principle

In plain terms: a nurse should treat patients whose lives can be saved with limited intervention before those who would need overwhelming resources or are beyond saving.

The START Algorithm

START = Simple Triage And Rapid Treatment. Assess three things in under 60 seconds each: RPM — Respirations, Perfusion, Mental status.

Can walk? Yes → GREEN (Minor) Respirations? None after airway → BLACK >30/min → RED Perfusion? Cap refill >2s → RED Mental status? Can't follow command → RED All normal → YELLOW

RED vs. BLACK

The hardest distinction in disaster triage is between RED (immediate) and BLACK (expectant). Both are critically injured — but only one can be saved with the resources available.

RED — Immediate
Severe but survivable injuries. Examples: airway obstruction, tension pneumothorax, severe controllable bleeding, shock that responds to fluids.
BLACK — Expectant
Injuries incompatible with survival given resources. Examples: pulseless/apneic after airway opened, massive head trauma, full-thickness burns over most of body.

How to Apply Triage

1
Call out the walking wounded. Anyone who can walk to a safe area is tagged GREEN.
2
Assess respirations. Open the airway; if no breathing returns, tag BLACK and move on.
3
Check perfusion. Capillary refill over 2 seconds or absent radial pulse → tag RED.
4
Check mental status. If they cannot follow simple commands → tag RED.
5
Tag YELLOW if RPM is stable but injuries are serious. Treat REDs first, then YELLOWs.

Worked Example 1

Reasoning: Respirations over 30/min automatically meets RED criteria in START. The compromised breathing is the priority — even though the patient is alert.

Worked Example 2

A
Walking, minor cuts
B
Tension pneumothorax, hypoxic
C
No pulse after airway opened
D
Closed arm fracture, stable

Worked Example 3

Reasoning: Applying $$ \text{Maximize} \;\; \sum S_i $$ the ventilator goes to the patient who can survive with it. Resources are not allocated by "first come first served" or by who is sickest, but by survival benefit.

Common Mistakes

✕ Treating sickest first
In a disaster, resources go to survivable patients — not those needing overwhelming care.
✕ Spending time on BLACK
Expectant patients get comfort care only. Don't delay treating REDs to attempt CPR.
✕ Forgetting to re-triage
Conditions change. A YELLOW can deteriorate to RED and must be reassessed.

Triage Summary

ColorPriorityMeaning
RED1 — ImmediateLife threat, survivable. Treat first.
YELLOW2 — DelayedSerious, can wait briefly.
GREEN3 — MinorWalking wounded, minimal care.
BLACK4 — ExpectantDeceased / unsurvivable. Comfort care.

Triage Is Dynamic

A triage tag is not permanent. As more resources arrive or a patient's condition changes, their category may change.

Question 1 of 5

In a disaster with limited resources, who should receive care first?

Question 2 of 5

A patient is apneic after the airway is opened and has no pulse. What triage color applies?

Question 3 of 5

In the START method, what does the first step identify?

Question 4 of 5

A patient has a respiratory rate of 34/min but is alert with a minor leg laceration. What color?

Question 5 of 5

A YELLOW-tagged patient suddenly begins to bleed heavily and lose consciousness. What should the nurse do?

Key Takeaways

1
Disaster goal: greatest good for the greatest number — maximize total survivors.
2
Order of treatment: RED → YELLOW → GREEN; BLACK gets comfort care.
3
START method: assess RPM — Respirations, Perfusion, Mental status.
4
Re-triage often: categories change as conditions and resources change.