START triage in a mass casualty incident
In a flooding disaster, the public health nurse must rapidly sort casualties so that limited transport and hospital resources go first to those who need immediate life-saving intervention. The Simple Triage and Rapid Treatment (START) algorithm uses four sequential assessments: ability to walk, respiratory rate, perfusion, and mental status. Because all four casualties in this scenario cannot walk and are breathing spontaneously, the decision moves to the next steps.
START assigns a
Red (immediate) tag when any one of the following is present: respiratory rate above
30/min, absent radial pulse or capillary refill longer than
2 seconds, or inability to follow simple commands. A casualty who fails none of these Red criteria but cannot walk is tagged
Yellow (delayed) [1].
Casualty 4 has a respiratory rate of
28/min, a present radial pulse, and can follow simple commands.
None of the three Red criteria is met, so this casualty is correctly classified as Yellow. The respiratory rate of 28/min is elevated but remains below the START threshold of 30/min, and perfusion and mental status are intact.
The other three casualties each meet one Red criterion. Casualty 1 has tachypnea at
32/min, which exceeds the respiratory cutoff. Casualty 2 has a capillary refill of
3 seconds, indicating delayed perfusion. Casualty 3 cannot follow simple commands, reflecting altered mental status. Each of these findings alone is sufficient for a Red tag under START
[1][2].
A key clinical point is that START is designed for speed and simplicity, not diagnostic precision.
The respiratory rate cutoff of 30/min and the capillary refill cutoff of 2 seconds are deliberately conservative thresholds intended to identify casualties who may be deteriorating and need immediate intervention. The protocol sacrifices some specificity to ensure high sensitivity for critical illness, which is appropriate in a mass casualty incident where overtriage is more acceptable than undertriage
[2][3].
Watch out! A respiratory rate of 28/min is not normal, but in START it does not trigger a Red tag by itself. Do not upgrade a casualty to Red based on clinical concern alone; follow the algorithm’s explicit cutoffs.
Key point! The order of assessment matters. In START, you check walking first, then breathing, then perfusion, then mental status. Once a Red criterion is found, you stop and tag Red — you do not continue to the next step. Casualty 4 passes all steps and is therefore Yellow.
| Casualty | Respiratory rate | Perfusion | Mental status | Red criterion met | START tag |
|---|
| 1 | 32/min | Radial pulse present | Follows commands | Tachypnea >30/min | Red |
| 2 | 24/min | Capillary refill 3 sec | Follows commands | Delayed capillary refill >2 sec | Red |
| 3 | 20/min | Radial pulse present | Cannot follow commands | Altered mental status | Red |
| 4 | 28/min | Radial pulse present | Follows commands | None | Yellow |
The rationale for using a simple, reproducible tool like START is supported by field experience. In a train crash disaster, START triage levels were compared with actual clinical outcomes, and the system performed well in identifying the most critically injured patients for priority transport
[2]. Although START was originally developed for prehospital use, its principles also inform hospital-based triage during mass casualty surges, where rapid categorization remains essential
[3].
References (research sources)
- [1]
START triage: does it work?Research articleGebhart ME, Pence R (2007) · DOI: 10.1016/j.dmr.2007.05.002
- [2]
Does START triage work? An outcomes assessment after a disaster.Research articleKahn CA, Schultz CH, Miller KT, Anderson CL (2009) · DOI: 10.1016/j.annemergmed.2008.12.035
- [3]
A review of mass casualty incident triage tools for hospital-based triage.Research articleAbdul-Nabi SS, Hitti E. (2025) · DOI: 10.4103/tjem.tjem_77_25