Start with the patient’s physiology
At triage, the useful question is what this patient needs next. A complaint label gives you a starting point; the examination tells you whether that label is safe.
This guide uses ESI Version 5, described in ENA’s fifth-edition handbook (2023). ENA’s triage education complements local training; an online course labelled 2.0 is not ESI Version 2.
The four decisions
A: An intervention needed immediately to sustain life means ESI 1: assisted ventilation, emergency pacing or hemorrhage resuscitation, for example. Routine IV access alone does not.
B: Otherwise, high risk, newly altered mentation, or severe pain/distress can establish ESI 2. A pain number alone is insufficient.
C: Only after A and B are excluded, predict resource types: none → ESI 5; one → ESI 4; two or more → ESI 3.
D: Reassess provisional levels 3–5 using age-appropriate vital signs. An abnormal value triggers clinical review, not automatic ESI 2. Normal values do not exclude danger.
Count resources correctly
Laboratory tests count together; radiographs and CT separately. IV hydration and parenteral drugs are distinct resources. Simple procedures count once; procedural sedation twice. Exclude oral drugs, point-of-care tests and simple dressings.
Young infants need a separate safety check
Febrile neonates need prompt assessment and at least ESI 2, or ESI 1 when immediate lifesaving treatment is needed.
For treatment decisions, use the age-specific infant pathway. The AAP febrile-infant guideline addresses well-appearing, term infants aged 8–60 days with temperature ≥38.0°C. It separates ages 8–21, 22–28 and 29–60 days because evaluation and management differ. It is not an ESI scoring rule and does not cover every infant. A newborn younger than eight days, an ill-appearing infant or a preterm infant falls outside that guideline’s stated population.
Keep the complete ESI age-specific vital-sign reference available; an abbreviated adult threshold is unsuitable for children.
Apply it: dizziness with a pulse of 34
Hypothetical case: an 80-year-old is dizzy and pale, with a pulse of 34/min. Being awake does not answer whether the circulation is adequate.
Bradycardia can reduce cardiac output. Check blood pressure, mental state, perfusion, ischemic symptoms and heart-failure findings while arranging monitored assessment. The 2025 AHA bradycardia algorithm distinguishes persistent bradycardia with cardiopulmonary compromise from cases without compromise and directs urgent treatment accordingly.
Immediate lifesaving treatment → ESI 1. High risk without that immediate need → ESI 2.
Make the handover useful
State what worries you, what you observed and what must happen next. “Dizzy, pulse 34, pale; perfusion assessment and monitoring underway” gives the receiving clinician more than a number alone. Record the time and the plan for reviewing anyone still waiting. If symptoms change, communicate the change directly.
Triage does not diagnose the cause or guarantee that a patient will remain stable.
References
ENA: Emergency Severity Index Handbook, fifth edition (2023); current triage education; AAP febrile-infant guideline (2021); AHA adult bradycardia algorithm (2025).
