Guide — Emergency Nursing
Emergency Department Triage
Triage is the systematic sorting of patients by urgency of need to ensure that the most critically ill receive care first. Accurate triage protects patients, optimizes resources, and is a core NCLEX and clinical competency.
11 min read · Emergency Nursing
Educational use only. This content is intended for nursing students and exam preparation. Clinical decisions require licensed professional judgment and institutional protocols. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
Purpose of Triage
The word triage derives from the French trier — to sort. In emergency nursing, triage accomplishes four core goals:
- ✦Identify immediately life-threatening conditions and intervene without delay
- ✦Assign priority level so the sickest patients receive care first — regardless of arrival order
- ✦Manage patient flow to prevent department overcrowding and delay of critical care
- ✦Provide initial assessment documentation for the clinical team
Triage is NOT a diagnostic process — the triage nurse assigns priority based on chief complaint, vital signs, and appearance, not a confirmed diagnosis. Triage decisions must be made quickly (typically within 2–5 minutes of patient arrival).
ESI (Emergency Severity Index) Overview
The Emergency Severity Index (ESI) is the most widely used triage system in the United States. It uses a 5-level scale that combines acuity (patient stability) and resource utilization (how many resources the patient will need).
| ESI Level | Severity | Resources Needed | Time to Provider |
|---|---|---|---|
| ESI 1 (Critical) | Requires immediate life-saving intervention | Unlimited — resuscitative measures | Immediately |
| ESI 2 (Emergent) | High-risk or severe pain/distress; may deteriorate quickly | Any number — expected complex workup | <10 minutes |
| ESI 3 (Urgent) | Stable but requires multiple resources to evaluate and treat | ≥2 resources (labs, IV, imaging) | Varies by volume |
| ESI 4 (Less Urgent) | Stable, likely needs only 1 resource | 1 resource | Non-urgent queue |
| ESI 5 (Non-Urgent) | Stable, no resources anticipated beyond exam | 0 resources | Non-urgent queue |
Resources in ESI = labs, IV/IM medications, IV fluids, imaging (X-ray, CT, ultrasound, ECG), specialist consultation, simple procedure. A physician exam alone does not count as a resource.
High-Risk Presentations — Never Undertriage These
Certain presentations carry high mortality risk if delayed. These should default to ESI 1 or ESI 2 and be escalated immediately regardless of normal-appearing vital signs.
Cardiac Emergencies (ESI 1–2)
- ✦STEMI — chest pain + ST elevation
- ✦Unstable angina with diaphoresis/radiation
- ✦Acute pulmonary edema — severe dyspnea + pink frothy sputum
- ✦Life-threatening dysrhythmias (VT, VF, complete heart block)
Neurological Emergencies (ESI 1–2)
- ✦Acute stroke — sudden facial droop, arm weakness, speech difficulty, FAST+
- ✦Subarachnoid hemorrhage — 'thunderclap' worst headache of life
- ✦Status epilepticus — ongoing seizure
- ✦Altered mental status of unknown etiology
Respiratory Emergencies (ESI 1–2)
- ✦Respiratory failure or arrest
- ✦Anaphylaxis with stridor or bronchospasm
- ✦Tension pneumothorax — absent breath sounds + tracheal deviation
- ✦Severe asthma or COPD exacerbation with accessory muscle use, SpO₂ <90%
Trauma & Other (ESI 1–2)
- ✦Penetrating chest or abdominal trauma
- ✦Hemodynamic instability (SBP <90, HR >120)
- ✦Septic shock — hypotension + suspected infection
- ✦DKA or HHS with altered mental status
- ✦Pediatric: fever + petechiae (meningococcemia)
Triage Assessment Process
General appearance (across the room assessment)
Before the patient reaches the desk: Are they walking, being carried, or unresponsive? Skin color, work of breathing, positioning, level of distress. A 'sick' or 'not sick' impression guides initial urgency. Trust clinical instinct.
Chief complaint and history
What brought you in today? Onset, duration, severity. Associated symptoms. Past medical history relevant to current complaint. Current medications, allergies. Last tetanus (trauma), last menstrual period (female of childbearing age). Mechanism of injury (trauma).
Vital signs
Temperature, heart rate, blood pressure, respiratory rate, SpO₂, pain scale, weight (pediatric patients). Vital signs may be within normal range early in shock or sepsis — do not rely on vitals alone. Trending is more important than single values.
Focused assessment
Brief targeted physical assessment relevant to chief complaint. Identify any immediately life-threatening findings. Apply the AVPU scale for mental status (Alert, Voice, Pain, Unresponsive) or GCS if altered mental status.
ESI level assignment and documentation
Assign ESI 1–5 based on acuity and anticipated resource needs. Document chief complaint, vitals, assessment findings, ESI level, time, and triage nurse signature. Place patient in appropriate treatment area or waiting room per ESI level.
Reassessment Intervals
| ESI Level | Reassessment Interval | Key Reassessment Focus |
|---|---|---|
| ESI 1 | Continuous monitoring | Continuous vital signs, resuscitation response, airway patency, hemodynamic stability |
| ESI 2 | Every 15 minutes | Vital sign trends, pain response, neurological changes, escalation triggers |
| ESI 3 | Every 30–60 minutes | Vital sign changes, symptom progression, lab/imaging results ready for handoff |
| ESI 4 | Every 1–2 hours or as needed | Symptom changes, escalation of care if condition worsens |
| ESI 5 | Every 2 hours or as needed | Monitor for unexpected deterioration |
Retriage: Any patient whose condition visibly worsens while waiting must be retried immediately — regardless of original ESI level. A patient initially triaged ESI 3 can rapidly deteriorate to ESI 1. The triage nurse is responsible for monitoring waiting room patients.
Nursing Priorities in Triage
Life-threatening conditions identified and acted on immediately
ESI 1 patients are brought to a treatment room and resuscitation begins before a physician arrives if necessary. Nurses do not wait for a physician order to initiate oxygen, monitoring, IV access, or position change in a coding patient.
ESI 2 patients are never left waiting without monitoring
A patient with chest pain, stroke symptoms, severe respiratory distress, or hemodynamic instability placed in the waiting room is at risk of rapid deterioration. Establish monitoring and notify charge RN and provider immediately.
Pediatric considerations
Children compensate well for shock — normal vital signs do not rule out serious illness. Fever + petechiae in any child = ESI 2 minimum (meningococcemia). Age-appropriate pain assessment tools. Weight in kilograms documented at triage for all pediatric patients.
Mental health and behavioral emergencies
Patients with suicidal ideation, homicidal ideation, or active psychosis are ESI 2 regardless of physical appearance. Remove access to sharps, IV lines, and call bells for safety. Complete safety search per protocol before room placement.
Documentation
Triage documentation must include: arrival time, chief complaint, mechanism (if trauma), vital signs, pain score, ESI level assigned, time assigned, any immediate interventions, allergies, last medications. Triage documentation is a medicolegal record — be precise and thorough.
NCLEX Pearls
- ✦Triage priority is determined by acuity (urgency of need), NOT order of arrival. The sickest patient always goes first.
- ✦ESI 1 = immediate life-saving intervention needed (CPR, intubation, defibrillation). Do not delay to take vitals first.
- ✦ESI 2 = high-risk situation — patient may deteriorate without immediate attention. Think: STEMI, stroke, septic shock, severe allergic reaction.
- ✦Resources in ESI: labs, IV/IM medications, fluids, imaging (CT, X-ray, ultrasound), ECG, specialist consult. A physician exam is NOT a resource.
- ✦NCLEX often asks which patient the nurse should see first — choose the patient with the most life-threatening or rapidly deteriorating condition.
- ✦Vital signs can be normal in early shock or early sepsis — never dismiss a sick-appearing patient because vitals are 'fine.'
- ✦Thunderclap headache (worst headache of life, sudden onset) = subarachnoid hemorrhage until proven otherwise → ESI 2.
- ✦Fever + petechiae in a child = meningococcemia = ESI 2 minimum — do not wait in waiting room.
- ✦Retriage is mandatory if a patient's condition worsens in the waiting room — reassignment from ESI 3 to ESI 1 can happen rapidly.
Related Resources
Standards & sources
Fact-checked Jun 20, 2026This page is written to align with Emergency Nurses Association (ENA) · AHA ACLS / PALS Guidelines · Advanced Trauma Life Support (ATLS). It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →