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Emergency Severity Index, Version 4: Implementation Handbook, 2012 Edition


The Emergency Severity Index (ESI) is a simple to use, five-level triage instrument that categorizes emergency department (ED) patients by evaluating both patient acuity and resources. The algorithm provides clinically relevant stratification of patients into five groups from 1 (most urgent) to 5 (least urgent). ED educators, clinicians, and managers can use this practical guide to develop and conduct an ESI educational program, implement the algorithm, and design an ongoing quality improvement program.

This handbook is arranged into the following chapters:
  1. Introduction to the emergency severity index: a research-based triage tool
  2. Overview of the emergency severity index
  3. ESI level 2
  4. ESI levels 3-5 and expected resource needs
  5. The role of vital signs in ESI triage
  6. The use of ESI for pediatric triage (new with this edition)
  7. Implementation of ESI triage
  8. Evaluation and quality improvement
  9. Practice cases
  10. Competency cases
The Web page also provides information for obtaining a DVD set of Emergency Severity Index, Version 4: Everything You Need To Know, as well as print copies of the Implementation Handbook.
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ESI Triage Research Team

Funding Sources

Agency for Healthcare Research and Quality

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  • Release Date: 05/2005
  • Review Date: 01/2012
  • Recent Summary: 01/2012
  • Original Summary: 05/2005
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Last updated: October 09, 2013.