Triage in mass casualty events

When multiple people are injured simultaneously and resources are insufficient to treat everyone at once, treating patients in order of arrival kills the ones who could have been saved. Triage — from the French word for "sorting" — is the discipline of rapidly categorizing casualties by survivability and resource need so that limited care reaches the right people first. The START system, developed in 1983 at Hoag Hospital and Newport Beach Fire Department, can be performed by a single untrained bystander in 30–60 seconds per patient. Learning it before a mass casualty event is the difference between a coordinated response and a futile one.

START triage flowchart for mass casualty events — five-step decision tree assigning Green, Yellow, Red, or Black categories based on walking ability, breathing, respiratory rate, pulse, and ability to follow commands

Educational use only

This page provides general educational information for emergency preparedness scenarios when professional medical care is unavailable. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified healthcare provider. Use this information at your own risk.

When triage applies

Triage is indicated whenever:

  • The number of injured people exceeds the immediate capacity to treat all of them
  • You are the only or one of few responders
  • Resource limitation forces prioritization — limited bandages, limited hands, limited transport
  • An ongoing hazard means not all patients can be reached at once

A single rescuer with two critically injured patients must triage. A preparedness group with one medic and six casualties must triage. Triage does not mean abandoning patients — it means ensuring the patients who can survive with treatment receive it first, rather than all resources going to the first person reached regardless of survivability.

Triage is emotionally brutal

You will assess people in front of you and move on without treating them. This is the correct action. Spending 20 minutes attempting resuscitation on an unsurvivable casualty while five salvageable patients bleed out is a failure of nerve, not an act of compassion. The discipline to move on is what makes triage work.

The four triage categories

Every triage system uses four categories. Colors are international standard.

Color Name Criteria Action
RED Immediate Life-threatening injury survivable with immediate intervention Treat now — this patient dies without care in minutes
YELLOW Delayed Serious injury but can wait 30–60 minutes Treat after Immediates — monitor for deterioration
GREEN Minor Ambulatory, minor injuries, can self-care or receive buddy care Do not tie up rescuer time — direct to a holding area
BLACK Expectant / Deceased Unsurvivable injuries or no signs of life Do not attempt resuscitation in an active MCI with multiple salvageable patients

The hardest category is BLACK — not just for obvious death (no breathing after airway repositioning) but for casualties with injuries that would require resources beyond what is available and still be unlikely to survive. In a hospital with a surgical team, these patients might be salvageable. In a field setting with one rescuer, pursuing them costs lives elsewhere.

The one exception to BLACK: pediatric patients (see JumpSTART below) and patients with environmental hypothermia are exceptions to the "no resuscitation" rule. A hypothermic patient may appear dead but survive full resuscitation.

START triage — step by step

START = Simple Triage And Rapid Treatment. It was designed to be performed by rescuers with basic first-aid training, in 30–60 seconds per patient, using only visual and tactile assessment.

The START sequence is called RPM: Respirations → Perfusion → Mental status.

Step 0 — Walking wounded (before RPM begins)

Before assessing individual patients:

  1. Call out loudly: "Anyone who can walk — come to me now" (or direct to a specific safe location).
  2. Everyone who responds and walks under their own power is GREEN. Direct them to a designated area. Assign one capable GREEN patient to monitor the group and report changes.
  3. This step clears ambulatory patients from the scene and lets you focus on non-ambulatory casualties who are more likely to be critically injured.

Step 1 — Respirations

Approach each non-ambulatory patient in sequence. Do not skip patients, do not return to previously assessed patients until the first pass is complete.

Is the patient breathing?

  • No: reposition the airway — head-tilt/chin-lift if no spinal injury concern, or jaw thrust if spinal injury is possible. Wait 5–10 seconds.
  • Still not breathing after repositioning: TAG BLACK. Move on.
  • Breathing after repositioning: TAG RED. Move on.
  • Yes: count or estimate the breathing rate.
  • Rate > 30 breaths per minute (labored, rapid, shallow): TAG RED. Move on.
  • Rate 10–29 breaths per minute (normal range): proceed to Step 2.
  • Rate < 10 breaths per minute (agonal, near absent): TAG RED (or BLACK if breathing is near-absent and repositioning does not improve it). Clinical judgment applies.

Field note

You do not need to count exactly. Watch the chest for 6 seconds and multiply by 10 — this gives you breaths per minute fast enough for a triage assessment. Labored breathing (visible effort, accessory muscle use, gasping) at any rate is RED.

Step 2 — Perfusion

For patients who passed Step 1 (breathing 10–29/min): assess circulation.

Method A — Radial pulse: Press two fingers to the inside of the wrist at the base of the thumb.

  • Absent radial pulse: TAG RED. Move on.
  • Present radial pulse: proceed to Step 3.

Method B — Capillary refill (when pulse assessment is difficult, or at night):

  • Press firmly on the patient's fingernail for 2 seconds, then release.
  • Normal: color returns to the nail bed within 2 seconds.
  • Capillary refill > 2 seconds (color is slow to return, stays pale or white): TAG RED. Move on.
  • Capillary refill ≤ 2 seconds: proceed to Step 3.

Note: capillary refill is less reliable in cold environments (peripheral vasoconstriction can slow refill in any patient) and in dark lighting. Use radial pulse when possible; use capillary refill as a backup or in poor conditions.

Step 3 — Mental status

For patients who passed Steps 1 and 2:

Give a simple command: "Squeeze my hand" or "Open your eyes" or "What's your name?"

  • Cannot follow commands (no response, inappropriate response, confused): TAG RED. Move on.
  • Can follow commands (squeezes hand, follows direction, answers appropriately): TAG YELLOW. Move on.

START summary — the decision tree

Not breathing → reposition airway
   → Still not breathing → BLACK
   → Breathing after reposition → RED

Breathing > 30/min → RED

Breathing 10–29/min → check perfusion
   → No radial pulse OR cap refill > 2 sec → RED
   → Pulse present AND cap refill ≤ 2 sec → check mental status
      → Cannot follow commands → RED
      → Can follow commands → YELLOW

Walking wounded (Step 0): all ambulatory patients → GREEN before Step 1 begins.

JumpSTART — pediatric modification

JumpSTART is the standard pediatric mass casualty triage algorithm, used for patients under 8 years old or under 50 lbs (23 kg). It parallels START but accounts for the physiological differences in children.

Key differences from adult START

Apneic pediatric patient — do not immediately tag BLACK:

In children, respiratory failure frequently precedes cardiac arrest. An apneic child with a pulse has a significantly greater chance of surviving resuscitation than an apneic adult.

If a pediatric patient is not breathing after airway repositioning: 1. Check for a pulse (brachial artery on the upper arm or femoral artery in the groin — radial pulse is less reliable in young children). 2. If no pulse: TAG BLACK. 3. If pulse is present: give 5 rescue breaths (mouth covering mouth and nose, gentle puffs just enough to see chest rise). - Breathing resumes: TAG RED. - Still not breathing after 5 breaths: TAG BLACK.

Respiratory rate thresholds (different from adults):

Rate JumpSTART classification
Not breathing, no pulse BLACK
Not breathing, pulse present — attempt 5 breaths RED if resumes; BLACK if not
< 15 breaths/min RED
15–45 breaths/min Continue to perfusion assessment
> 45 breaths/min RED

Normal respiratory rate for young children is higher than adults (15–30 is normal at rest; a distressed child may breathe at 30–45 and still have acceptable reserve). The adult threshold of > 30 = RED is not applicable.

Mental status — use AVPU for children:

Children may not follow verbal commands due to age, fear, or developmental stage. Use: - A — Alert (age-appropriate alertness): YELLOW - V — Responds to Voice: YELLOW - P — Responds to Pain only: RED - U — Unresponsive: RED

SALT triage — alternative system

SALT = Sort, Assess, Lifesaving Interventions, Treatment/Transport. Developed as a national all-hazards MCI standard endorsed by ACEP, ACS-COT, and NAEMSP.

SALT allows brief immediate lifesaving interventions (LSI) during the sorting phase that START does not. This makes it more appropriate in settings where tourniquet application or airway opening is feasible during initial assessment.

SALT sorting sequence

  1. Wave/Walk first: any patient who can walk or wave purposefully → assessed last (lower acuity).
  2. Purposeful movement but not walking: assessed second.
  3. Still / obvious life threat (no movement): assessed first.

SALT lifesaving interventions during assessment

SALT permits the following interventions during the sort/assess phase (not a full treatment): - Apply tourniquet to life-threatening extremity hemorrhage - Open the airway (reposition, jaw thrust) - 5 rescue breaths for pediatric patients - Needle decompression for tension pneumothorax (if trained and equipped)

After LSI, the patient is tagged using similar categories to START/JumpSTART.

START vs. SALT: when to use which

Factor START SALT
Rescuer training Basic — works with no medical training Better with some medical training
Speed Faster (no interventions during sort) Slightly slower (brief LSI allowed)
Setting Multi-victim trauma scenes All-hazards, including HAZMAT, blast
Pediatric Requires JumpSTART modification Built-in pediatric protocol
Adoption Most widely used in US EMS Endorsed as national standard

In a preparedness context, learning START is sufficient for most scenarios. If your group includes medically trained members, SALT provides a framework that matches their capabilities better.

Running the scene as a single responder

The hardest triage scenario is the solo responder. One person, no backup, multiple casualties. Follow this sequence:

  1. Scene safety first — you cannot triage if you become a casualty. Identify ongoing hazards (fire, active threat, structural collapse, chemical exposure). Position upwind and uphill if applicable.
  2. Call for help — shout, use radio, call 911. Do this before beginning patient assessment. Give dispatch: location, approximate patient count, mechanism of injury.
  3. Announce for walking wounded: "Anyone who can walk — come to me!" Direct GREEN patients to a safe gathering point. Assign the most capable GREEN person to keep that group together and call out if anyone worsens.
  4. Move through remaining patients in a systematic path — do not skip back, do not return to a patient mid-pass. Move in rows or a grid.
  5. 30–60 seconds per patient maximum — RPM only. No treatment during the first pass except opening airways for patients who become breathable (these get RED, not BLACK).
  6. Tag every patient as you go — use what you have:
  7. Permanent marker on the forehead or back of hand (R/Y/G/B or words)
  8. Triage tags if in your kit (fold or tear to show category)
  9. Masking tape with marker on clothing
  10. Color-coded flagging tape from a work kit
  11. After first pass: announce to any incoming responders — "I have [number] patients: [number] RED at [location], [number] YELLOW, all GREEN are at [location]." This 10-second brief saves the next responders minutes of scene orientation.
  12. Begin treatment with RED patients in the order you tagged them. Pair each RED with a YELLOW or GREEN bystander to maintain monitoring while you move to the next RED.

What to do during triage — and what to not do

Do during triage Do NOT do during triage
Reposition airway for apneic patients Begin cardiopulmonary resuscitation (CPR) (exception: JumpSTART 5 breaths for pediatric with pulse)
Apply tourniquet to life-threatening extremity bleed (SALT only during sort) Wound care or bandaging
Move patients out of immediate danger Detailed patient history
Tag and mark clearly Phone calls or documentation until all patients are tagged
Reassure briefly as you move Stop at one patient to provide comfort

Re-triage — when to reassess

Triage status is not permanent. Patients change.

Re-triage whenever: - More time has passed and treatment resources have not arrived (YELLOW patients become RED) - A patient you tagged YELLOW is now showing shock signs - A new responder arrives and can free up your hands for re-assessment - Treatment of a RED patient has succeeded (they may now be YELLOW) - Environmental conditions worsen (temperature drop, smoke, flooding)

Build a re-triage cycle of every 10–15 minutes into your scene management once the initial sort is complete.

Triage tags and marking

Purpose-built triage tags (METTAG, SMART Tag) are folded tear-off cards that move through the color categories as the patient's status changes. Each tag includes spaces for:

  • Patient name/description
  • Mechanism of injury
  • Vital signs assessed
  • Interventions performed
  • Time of assessment

In the absence of commercial tags, any clear system works — the goal is a mark that the next responder can read in 2 seconds without asking questions.

Field improvisations in order of preference: 1. Masking tape + permanent marker on the patient's forehead or dominant hand 2. Marker directly on forehead (washes off — note this in your kit) 3. Colored ribbon or flagging tape tied to the wrist 4. Notes on a phone or notepad if reliable power exists

Triage in a preparedness group

A prepared group of 4–12 people can function as a coordinated triage and treatment team if roles are pre-assigned.

Role Responsibility
Triage officer Assesses only — does not treat. Moves through patients, calls categories, delegates treatment. One person, the most medically trained.
Treatment lead Receives RED patients and begins interventions (bleeding control, airway, etc.)
Supply runner Moves equipment from kit to where it is needed
Documentation Tracks patients, interventions, and times. Can be any capable person.
Communications Calls EMS, manages radio, coordinates with incoming responders
Green area monitor Watches GREEN patients for deterioration, prevents them from re-entering the scene

The triage officer role is critical and counterintuitive — a highly skilled medical provider should resist the urge to treat and instead maintain the triage function. One person assessing all patients is faster than having every provider stop to treat the first RED patient they reach.

Practice drill: Run a tabletop once every six months with your group. Assign 3–5 "casualties" with index cards describing their injuries. Time the triage pass. Debrief on decisions made under time pressure. The 30-second patient limit feels impossible until you have practiced it.

Common triage mistakes

Mistake Why it happens Correct action
Treating before triaging Emotional response to visible suffering Tag all patients before treating any — first pass only
Over-tagging everyone RED Wanting to ensure everyone gets care Follow RPM exactly; a walking patient is GREEN
Under-tagging to avoid the BLACK decision Reluctance to designate anyone expectant BLACK is the correct category for unsurvivable injuries with limited resources
Returning to one patient repeatedly Familiarity, emotional connection Complete the full pass before returning to any patient
Skipping pediatric modification Not recognizing age difference Children under 8 get JumpSTART, not START
Forgetting to re-triage Initial pass feels final Build re-triage into your scene management cycle

Triage readiness checklist

  • Memorize the START sequence: Walking wounded (GREEN) → Respirations → Perfusion → Mental status
  • Know the RPM mnemonic: 30-2-Can Do (respirations < 30, perfusion present, can follow commands = YELLOW)
  • Know JumpSTART difference: apneic child with pulse → 5 rescue breaths before BLACK
  • Keep a permanent marker and triage tags (or masking tape) in every trauma kit
  • Assign triage officer role in your group before an incident occurs
  • Practice the 30-second patient limit in tabletop drills at least twice a year
  • Know your evacuation plan: where do RED patients go first?

Triage works because it is disciplined, fast, and impersonal. It requires that you override the instinct to stop at the most visibly distressed patient and force yourself to assess the entire scene. The preparedness context pairs triage directly with bleeding control — the intervention most likely to convert a RED patient to survivable — and with shock management for the ongoing care of tagged patients while awaiting evacuation. Gunshot wounds are among the most common RED-category presentations in any ballistic mass casualty event; the hemorrhage control and cavity wound management procedures there apply directly to your triage treatment sequence. If you are the first trained person on any mass casualty scene, triage is your highest-value contribution to survival outcomes.