From the Guidelines
The Emergency Severity Index (ESI) triage system is a highly effective tool for categorizing patients in emergency departments, with its five-level classification approach significantly improving patient outcomes, as evidenced by the American Heart Association's recommendation for its use in stroke patient triage 1. The ESI system has been refined over time to categorize patients based on acuity and resource needs, with level 1 representing patients requiring immediate life-saving interventions and level 5 representing non-urgent cases.
- Key benefits of the ESI system include:
- Reduced wait times for critically ill patients
- Decreased mortality rates
- Improved resource allocation
- Enhanced communication among healthcare providers The system's effectiveness stems from its algorithmic approach that considers both patient stability and anticipated resource requirements, allowing for more objective and consistent triage decisions, as seen in the context of stroke patient care where timely assessment and treatment are critical 1. For successful implementation, hospitals should provide comprehensive staff training, regular competency assessments, and continuous quality improvement monitoring, with a focus on maintaining high-quality triage practices through regular audits.
- Important metrics to evaluate ESI effectiveness include:
- Undertriage and overtriage rates
- Time-to-provider evaluations
- Patient outcomes by triage category While the ESI system has proven reliable across diverse emergency settings, its effectiveness depends on proper staff training and consistent application of the algorithm, highlighting the need for ongoing education and quality improvement initiatives 1.
From the Research
Development of Emergency Severity Index (ESI) Triage
- The Emergency Severity Index (ESI) is a five-level emergency department triage algorithm that provides stratification of patients on the basis of acuity and resource needs 2, 3.
- The ESI triage system was developed to improve the accuracy of triage assignments and to reduce the time waiting to be seen by a physician 2.
- The algorithm was introduced to triage nurses at two university hospital EDs, and implemented into practice with reinforcement and change management strategies 2.
Outcomes of ESI Triage
- The ESI triage system has been shown to be effective in stratifying patients into five groups with distinct clinical outcomes 2.
- Hospitalization was strongly associated with triage level, decreasing from 92% of patients in triage category 1 to 2% in triage category 5 2.
- Median lengths of stay were two hours shorter at either triage extreme (high and low acuity) than in intermediate categories 2.
- The ESI assigned upon arrival correlated with the median waiting time, exposing undertriaged patients to longer waiting times 3.
- The implementation of the ESI system has been shown to improve some indicators of emergency and improve the performance indices 4.
Comparison with Other Triage Systems
- The ESI triage system has been compared with other triage systems, such as the spot check triage, and has been shown to be more effective 4.
- The ESI system has also been compared with the Manchester Triage System (MTS), and both systems have been shown to be effective in identifying patients at increased risk of death and guiding them to rapid and correct treatment 5.
Accuracy of ESI Triage
- The accuracy of the ESI triage system has been evaluated, and it has been shown that certain factors, such as age and vital signs, can affect the accuracy of triage assignments 6.
- The study found that increasing age was a significant factor associated with odds of under-triage, and that certain vital signs, such as severe bradycardia, tachycardia, and severe hypoxia, were connected to the risk of under-triage of moderate acuity 6.