Emergency Severity Index
| ESI-1 | ESI-2 | ESI-3 | ESI-4 | ESI-5 | |
|---|---|---|---|---|---|
| ABC, airway, breathing, circulation; ESI, Emergency Severity Index. | |||||
| Vital functions (ABC) and level of consciousness | Unstable or unresponsive | Threatened or severe pain/distress | Stable | Stable | Stable |
| Life threat or organ threat | Obvious | Reasonably likely | Unlikely (possible) | No | No |
| Requires resuscitation | Immediately | Sometimes | Seldom | No | No |
| Expected resource use—x rays, labs, consultations, procedures | Maximum (⩾2) | High (⩾2) | Medium (⩾2) | Low (1) | Low (none) |
| Response time | Immediate team effort | Minutes | Up to 1 h | Can be delayed | Can be delayed |