Each ED should have its own acuity system. The 3-level system is most basic. One 5-level system, the Emergency Severity Index (ESI), groups patients according to their acuity and the resources needed to provide care. Group 1 is most urgent and group 5 is least urgent.
| Level | Acuity | Treatment and reassessment time | Sample conditions |
|---|---|---|---|
| 1 | Emergent | Immediate | Respiratory distress, coma |
| 2 | Urgent | 20 min-2 hr | Noncardiac chest pain, severe abdominal pain |
| 3 | Nonurgent | 2-4 hr | Sprains, earaches |
