Reference — Emergency Nursing
ESI Triage Levels Reference
Emergency Severity Index (ESI) quick reference — patient criteria, resource utilization, example presentations, reassessment intervals, and nursing actions for ESI 1 through ESI 5.
Educational use only. This content is intended for nursing students and exam preparation. Always follow your institution's triage protocols and ESI implementation guidelines. 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.
Requires immediate life-saving intervention. Patient is in immediate danger of death without intervention now.
Patient Criteria
- ✦Not breathing or apneic
- ✦Pulseless (cardiac arrest)
- ✦Severe respiratory distress with impending respiratory failure
- ✦Unresponsive or minimally responsive (GCS ≤8)
- ✦Active, uncontrolled hemorrhage
- ✦SpO₂ <80% not responding to oxygen
- ✦Active status epilepticus
Example Presentations
- —Cardiac arrest (CPR in progress on arrival)
- —Respiratory arrest — apneic with cyanosis
- —Unresponsive trauma patient with uncontrolled bleeding
- —Active status epilepticus
- —Anaphylaxis with loss of consciousness and no pulse
| Resources | Unlimited — all resuscitative resources deployed simultaneously |
| Time to provider | Immediately — nurse initiates intervention before provider arrival if necessary |
| Reassessment | Continuous monitoring |
| Nursing action | Activate trauma/code team immediately. Initiate ABCDE. Do NOT leave patient. Begin CPR/airway management as trained. Call for help and documentation simultaneously. |
Patient is in a high-risk situation, severely distressed, or may rapidly deteriorate without rapid assessment and intervention.
Patient Criteria
- ✦High-risk chief complaint that requires rapid evaluation
- ✦Confused, lethargic, or disoriented on presentation
- ✦Severe pain or distress (pain scale 8–10 with physiological signs)
- ✦Vital sign instability: SBP <90, HR >130, RR >28, SpO₂ <92% on room air, temp >104°F (40°C) or <96°F (35.5°C)
Example Presentations
- —Chest pain with diaphoresis and radiation to left arm (possible STEMI)
- —Sudden onset of facial droop, arm weakness, slurred speech (acute stroke — FAST positive)
- —'Worst headache of my life' (subarachnoid hemorrhage until proven otherwise)
- —High fever (>104°F) with altered mental status (meningitis, sepsis)
- —Suicidal patient with a plan, means, and intent
- —Anaphylaxis with hives and throat tightening but maintaining airway
- —Child with fever + petechiae (meningococcemia)
- —Hemodynamic instability: HR 130, BP 82/50, diaphoresis
| Resources | Any number anticipated — often requires labs, imaging, IV access, specialist |
| Time to provider | Within 10 minutes |
| Reassessment | Every 15 minutes while in waiting area |
| Nursing action | Do not allow ESI 2 patients to remain in waiting room unmonitored. Apply cardiac monitor and SpO₂ immediately. Notify provider. Begin IV access and labs per standing orders. |
Patient is stable and not in immediate danger, but requires two or more resources to evaluate and treat. Most ED visits fall into this category.
Patient Criteria
- ✦Vital signs are stable and within acceptable parameters
- ✦No immediate threat to life
- ✦Complaint requires multiple resources: labs AND imaging AND/OR IV medications
Example Presentations
- —Abdominal pain requiring labs, CT scan, and IV pain medications
- —UTI with fever requiring urinalysis, culture, and IV antibiotics
- —Ankle injury requiring X-ray and analgesics
- —Chest pain (non-cardiac appearing) requiring ECG, troponin, CXR
- —Moderate asthma exacerbation — stable on initial SpO₂
- —Diabetic patient with blood glucose 450, no AMS — requires labs and insulin
| Resources | ≥2 resources anticipated (e.g., labs + IV fluid + imaging) |
| Time to provider | Varies by department volume — typically within 1–2 hours |
| Reassessment | Every 30–60 minutes while waiting |
| Nursing action | Assign to treatment room or fast-track based on volume. Initiate standing orders as available. Triage nurse monitors waiting room for ESI 3 deterioration. |
Patient is stable. Only one resource needed. Condition is not expected to deteriorate.
Patient Criteria
- ✦Vital signs normal
- ✦No acute distress
- ✦Complaint expected to require only one resource
Example Presentations
- —Simple laceration requiring wound closure only
- —Urinary symptoms requiring urinalysis only (no fever, no AMS)
- —Sprained ankle requiring X-ray only
- —Ear pain with suspected otitis media — exam and prescription only
- —Sore throat with strep test needed
| Resources | 1 resource only (e.g., X-ray alone, or urinalysis alone, or wound care alone) |
| Time to provider | Non-urgent — may have extended wait |
| Reassessment | Every 1–2 hours |
| Nursing action | Fast-track appropriate if available. Educate on expected wait. Monitor for deterioration. |
Patient is stable. No resources anticipated beyond a physical examination. Complaint is minor and non-urgent.
Patient Criteria
- ✦Vital signs normal
- ✦No distress
- ✦Requires only a physical examination — no labs, no imaging, no IV medications
Example Presentations
- —Cold symptoms, mild URI — requesting documentation only
- —Prescription refill (no immediate need)
- —Bug bite without signs of infection or allergic reaction
- —Minor rash without systemic symptoms
- —Follow-up for already-diagnosed stable condition
| Resources | 0 resources anticipated (examination only) |
| Time to provider | Non-urgent — longest expected wait |
| Reassessment | Every 2 hours |
| Nursing action | Appropriate for fast-track or redirection to urgent care. Provide estimated wait time. Monitor waiting room for unexpected deterioration. |
Resource Definition in ESI
A “resource” in ESI = laboratory tests, IV/IM medications, IV fluids (for rehydration), specialty imaging (CT, X-ray, ultrasound, MRI), ECG (12-lead), specialist consultation, or simple procedure. A physician examination does NOT count as a resource.
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 →