Applies ESI triage methodology to assign acuity levels based on presenting complaints, vital signs, and resource needs. Use when triaging ED patients, assigning acuity scores, or prioritizing emergency cases.
Applies the Emergency Severity Index (ESI) triage methodology to assign acuity levels based on presenting complaints, vital signs, and anticipated resource needs.
Triage errors in the emergency department are a leading contributor to adverse patient outcomes. Studies show that undertriage occurs in 5-10% of ED visits and is associated with a 2-4x increase in mortality for patients who should have been assigned a higher acuity level. The Emergency Severity Index (ESI), now in version 4, is the most widely adopted triage algorithm in the United States and is endorsed by the American College of Emergency Physicians (ACEP) and the Emergency Nurses Association (ENA).
Accurate triage determines not only patient placement and timing of physician evaluation but also drives resource allocation, staffing decisions, and CMS quality metrics. The Joint Commission requires documented triage assessments, and incorrect acuity assignment can trigger compliance findings. This skill ensures consistent, defensible triage documentation that aligns with ESI v4 methodology and supports both clinical decision-making and regulatory requirements.
Before applying the full ESI algorithm, screen for immediate life threats requiring resuscitative intervention.
ESI Level 1 criteria (any one present):
| Criterion | Examples |
|---|---|
| Unresponsive | GCS ≤8, no purposeful movements |
| Pulseless / apneic | Cardiac arrest, respiratory arrest |
| Intubated / active resuscitation | Arrived on BVM, active CPR |
| Severe hemodynamic instability | SBP <80 with AMS, active massive hemorrhage |
| Acute overdose with obtundation | GCS <12, respiratory depression |
If any Level 1 criterion is met, assign ESI-1 immediately and activate the resuscitation team. Do not proceed further in the algorithm.
If the patient is not ESI-1, evaluate for high-risk situations that require rapid physician evaluation.
ESI Level 2 criteria — answer these three decision points:
Should this patient not wait? Conditions where delay causes irreversible harm:
Is there new-onset confusion, lethargy, or disorientation? Any acute change in mental status = ESI-2.
Is the patient in severe distress? Clinical judgment of severe pain (NRS ≥8) or severe emotional distress requiring immediate intervention.
Vital sign danger zone flags (auto-trigger ESI-2):
| Vital Sign | Adult Danger Zone |
|---|---|
| HR | <50 or >130 |
| SBP | <90 or >200 |
| RR | <10 or >30 |
| SpO2 | <92% on room air |
| Temp | >104°F (40°C) or <95°F (35°C) |
For patients who are not ESI-1 or ESI-2, predict the number of ED resources needed.
Resource counting rules (per ESI v4 Handbook):
Resources that COUNT (each = 1 resource):
Resources that DO NOT count:
Assignment table:
| Predicted Resources | ESI Level | Typical Examples |
|---|---|---|
| ≥2 | ESI-3 | Abdominal pain needing labs + CT; chest pain needing ECG + troponin + CXR |
| 1 | ESI-4 | Simple laceration repair; single X-ray for ankle injury |
| 0 | ESI-5 | Prescription refill; suture removal; medication recheck |
Vital sign check for ESI-3: After assigning ESI-3, re-check vital signs against danger zone criteria. If vital signs fall in danger zone, uptriage to ESI-2.
| ESI Level | Reassessment Interval | Scope |
|---|---|---|
| ESI-1 | Continuous | Full vital signs + neuro checks |
| ESI-2 | Every 15-30 min | Vital signs + chief complaint status |
| ESI-3 | Every 60 min | Vital signs + pain reassessment |
| ESI-4 | Every 120 min | Brief check-in, vital signs PRN |
| ESI-5 | Every 120 min | Brief check-in |