ABCDE and triage for the acutely ill (Basic Emergency Care)

WHO Basic Emergency Care · reviewed October 2026 · gpreasoning.uk/global

Reasoning GP
Global Primary Care

Who / when

Every patient arriving at a facility (triage), and any patient who is acutely ill, injured or getting worse (ABCDE).
Before you start: is the scene safe (fire, traffic, violence, chemicals)? Gloves and eye protection; call for help early if several people are hurt.

Red flags: refer now

Triage: RED, move to resuscitation now (age 12 and over)

Unresponsive. Stridor. Respiratory distress or central cyanosis.
Capillary refill over 3 seconds; weak, fast pulse; heavy bleeding; pulse under 50 or over 150.
Active convulsions; low glucose; any two of: altered mental state, stiff neck, headache, fever or low temperature.
High-risk trauma; poisoning or dangerous chemical exposure; threatened limb; snakebite; acute chest or abdominal pain over age 50; violent or aggressive.
Pregnant with: heavy bleeding, severe abdominal pain, fits or altered mental state, severe headache, visual changes, BP 160/110 or more, active labour, or trauma.

Children under 12 have their own IITT chart: use it.

Assess

SAMPLE history (after the ABCDE)

S: Signs and symptoms: what happened, when
A: Allergies
M: Medicines, including traditional remedies
P: Past illnesses, pregnancy
L: Last oral intake
E: Events leading up to the illness or injury

Then a full set of vital signs: BP, pulse, breathing rate, temperature, oxygen saturation and glucose.

Classify

Interagency Integrated Triage Tool (IITT), age 12 and over.
Category	Includes	Where
RED: high acuity	Any red criterion (see Red flags)	Resuscitation area, seen immediately
YELLOW: moderate acuity	Facial or neck swelling; wheeze; vomiting everything, ongoing diarrhoea or unable to drink; severe pallor; ongoing bleeding; recent fainting; agitation or confusion; acute weakness, focal neurological or visual problem; severe pain; limb deformity, open fracture, dislocation; other trauma or burns; sexual assault; unable to pass urine; pregnancy referred for complications; exposure needing urgent prophylaxis (animal bite, needlestick)	Treatment area, seen soon
Up-triage	Pulse under 60 or over 130; breathing under 10 or over 30; temperature under 36 or over 39 °C; SpO₂ under 92%; AVPU anything other than Alert; or clinical concern	Immediate review by the supervising clinician
GREEN: low acuity	None of the above	Waiting area; reassess if worse

Treat

ABCDE: assess and act in this order; fix each problem before moving on

	Look for	Do now
A Airway	Can they talk? Stridor, snoring, gurgling, secretions, swelling, foreign body	Head-tilt chin-lift (jaw thrust if trauma); suction; airway adjunct; back blows or thrusts if choking. Swelling, hives or stridor: IM adrenaline
B Breathing	Rate, effort, wheeze, unequal breath sounds, SpO₂	Oxygen if fast breathing or hypoxic; bag-valve-mask if breathing inadequate; salbutamol for wheeze; tension pneumothorax: needle decompression
C Circulation	Cool skin, capillary refill over 3 s, fast pulse, low BP, bleeding (external and internal)	Stop bleeding with direct pressure; IV access; fluids for shock; bind pelvis, splint femur
D Disability	AVPU (GCS in trauma), glucose, pupils, limb movement, seizures	Glucose if under 3.5 mmol/L or untestable and confused; recovery position if no trauma; benzodiazepine for seizures; magnesium sulphate if pregnant; naloxone for small pupils and slow breathing
E Exposure	Hidden injuries, rashes, bites, temperature	Cover to prevent hypothermia; remove wet clothes; immobilise a bitten limb; log roll if spinal injury possible

WHO BEC doses (adults)

Adrenaline 1 mg/mL (1:1000) for anaphylaxis or severe wheeze: 0.5 mg IM if 50 kg or more; repeat every 5 minutes as needed.
Shock: normal saline or Ringer's lactate 1 litre in under 30 minutes; reassess; a second litre if still shocked and no fluid overload. Severe anaemia, malnutrition or fluid overload: 500 mL at a time.
Glucose: 25 to 50 mL of 50% IV (or 125 to 250 mL of 10%). No IV: 2 to 5 mL of 50% glucose or sugar solution inside the cheek.
Diazepam for seizures: 10 mg slow IV or 20 mg rectally; after 10 minutes 5 mg IV or 10 mg rectally. Watch breathing.
Aspirin 300 mg chewed for a suspected heart attack.

Follow-up

Repeat the ABCDE after every intervention and whenever the person changes or worsens.
Recheck vital signs often while waiting for transfer.
Reassess people waiting in yellow and green; up-triage if they worsen.

Counsel

Tell the person and family what you are doing and why, in simple words.
Explain why some people are seen before others.
Respect privacy and dignity while examining.

We are checking the most dangerous things first: breathing, blood and the brain. Then we will ask you more questions.

When to refer

Arrange transfer as early as possible for: airway problems needing advanced management; tension pneumothorax after decompression; internal bleeding; shock not responding to 2 litres; head injury with unequal pupils; severe burns; snakebite; anything beyond your facility.
Hand over with ABCDE findings, SAMPLE history, treatments given and times, and the response.
Keep monitoring and treating on the way.

Sources

World Health Organization and International Committee of the Red Cross. Basic emergency care: approach to the acutely ill and injured. Participant workbook. 2018. World Health Organization, International Committee of the Red Cross and Médecins Sans Frontières. Interagency Integrated Triage Tool (age 12 and over) and reference card. 2023.

Adapted from WHO guidance; not endorsed by WHO. This page paraphrases and adapts the WHO publications listed under Sources, which are licensed CC BY-NC-SA 3.0 IGO; the adapted text is shared under the same licence for non-commercial education. Reasoning GP is not affiliated with WHO or any other organisation named here. Use it alongside your national guidelines, essential medicines list and formulary, and your clinical judgement. Doses are given only where they come from a WHO source; otherwise follow your national guideline or formulary.