Triage is a dynamic process used by medical professionals to sort and prioritize patients based on the severity of their condition and the need for immediate care. This system is necessary when the number of injured people exceeds available resources, ensuring the greatest good is done for the greatest number of potential survivors. Triage forms the first step in managing any influx of patients, whether from a mass casualty incident or a busy emergency department. The goal is to quickly assess a patient’s stability to determine how long they can safely wait for definitive treatment.
The Foundational Three-Tier Classification
The concept of triage is built upon a foundational three-level classification system, often employed during mass casualty events or in field training. This system relies on color-coding to quickly communicate patient priority to first responders and medical personnel.
Red (Immediate)
This category is reserved for patients with life-threatening injuries who require intervention within minutes to survive, such as those with severe hemorrhage or an obstructed airway.
Yellow (Delayed)
This is assigned to individuals with serious injuries that require care within a few hours, but their conditions are not immediately life-threatening after initial stabilization. Examples include stable major fractures or moderate burns, where treatment can be postponed without significantly increasing the risk of death.
Green (Minor)
This designates the “walking wounded” who have small cuts, sprains, or other injuries that can wait for care until after higher-priority patients have been treated.
The full foundational classification includes a fourth category, Black, which designates the Expectant or Deceased. This applies to patients whose injuries are so severe that survival is unlikely even with immediate care, or those who are already deceased. In resource-constrained situations, these individuals are not the focus of immediate life-saving efforts so that limited medical resources can be directed toward those with a higher chance of survival.
Criteria for Assigning Triage Priority
A triage officer determines priority by rapidly assessing specific physiological parameters and clinical indicators. The process centers on evaluating the Airway, Breathing, and Circulation, commonly referred to as the ABCs. An immediate red tag is assigned if the patient has a compromise to any of these systems, such as a respiratory rate outside the normal range or an absent radial pulse, indicating poor circulation.
The assessment also includes a rapid check of the patient’s mental status or level of consciousness, which indicates a severe head injury or inadequate blood flow to the brain. A patient unable to follow simple commands is often categorized as Immediate (Red), even if their breathing and circulation appear stable. The mechanism of injury, such as a high-speed motor vehicle collision, also influences the initial prioritization, suggesting the potential for internal injuries.
Triage in Modern Emergency Departments
While the three-tier system is a quick sorting method for mass casualty incidents, modern Emergency Departments (EDs) rarely rely on only three levels for daily operations. Hospital settings require a finer distinction between urgency levels to manage patient flow effectively. Most contemporary EDs utilize five-level triage systems, such as the Emergency Severity Index (ESI) in the United States or the Manchester Triage System (MTS).
These five-level systems enhance accuracy by stratifying patients into five distinct acuity groups.
- Level 1 (Resuscitation): Reserved for patients who require immediate, life-saving interventions, such as those in cardiopulmonary arrest.
- Level 2 (Emergent): Includes high-risk situations or patients with severe pain who must be seen by a provider within minutes.
- Level 3 (Urgent): Allows for a nuanced categorization of stable patients who require multiple resources.
- Level 4 (Semi-Urgent): Stable patients who require fewer resources than Level 3.
- Level 5 (Non-Urgent): Stable patients who can safely wait the longest.
The ESI system assigns Levels 3 through 5 based on the anticipated number of resources (e.g., laboratory tests or X-rays) a patient will need, alongside their vital signs. This approach ensures that patients who can safely wait are seen after those with time-sensitive conditions, optimizing the use of personnel and equipment.