What are the different triage categories in a clinical setting?

Clinical Triage Categories

Triage categories in clinical settings are standardized systems that prioritize patients based on the severity of their condition to ensure those with the most urgent medical needs receive timely care. The most widely accepted triage systems use five levels to categorize patients according to acuity and urgency of care required 1.

Standard Five-Level Triage Systems

Four internationally recognized five-level triage systems are currently in use:

1. Australasian Triage Scale (ATS)

   • Categorizes patients based on symptoms using specific descriptors
   • Focuses on symptom presentation and physiological parameters

2. Manchester Triage System (MTS)

   • Uses defined presentational flow charts combined with clinical indicators
   • Structured approach with specific pathways for different presenting complaints

3. Canadian Triage and Acuity Scale (CTAS)

   • Based on the ATS but also incorporates diagnoses
   • Combines physiological parameters with clinical presentations

4. Emergency Severity Index (ESI)

   • First excludes life-threatening and severe conditions
   • Then stratifies remaining patients according to estimated resource utilization
   • Two-step approach focusing on both acuity and resource needs

Common Triage Categories

The five standard levels used in most emergency department triage systems are:

1. Level 1 (Red) - Resuscitation/Immediate

   • Life-threatening conditions requiring immediate intervention
   • Examples: cardiac arrest, severe trauma, respiratory failure
   • Time to physician: Immediate

2. Level 2 (Orange) - Emergent/Very Urgent

   • High-risk conditions that could rapidly deteriorate
   • Severe pain or distress
   • Time to physician: Within 10-15 minutes

3. Level 3 (Yellow) - Urgent

   • Conditions requiring treatment but with stable vital signs
   • Moderate pain or distress
   • Time to physician: Within 30-60 minutes

4. Level 4 (Green) - Semi-urgent/Standard

   • Minor injuries or illnesses
   • Minimal pain or distress
   • Time to physician: Within 1-2 hours

5. Level 5 (Blue) - Non-urgent

   • Minor conditions that could be treated in primary care settings
   • Chronic or minor acute conditions
   • Time to physician: Within 2-4 hours

Mass Casualty Triage Systems

During mass casualty incidents, specialized triage systems are employed:

1. START (Simple Triage And Rapid Treatment)

   • Categorizes patients into four groups: Immediate (red), Delayed (yellow), Minor (green), and Deceased/Expectant (black)
   • Based on ability to walk, respiratory rate, perfusion, and mental status 2

2. SALT (Sort, Assess, Lifesaving Interventions, Treatment/Transport)

   • More recent system with similar categories to START
   • Includes early lifesaving interventions during the triage process 2

Critical Care Triage During Disasters

During disasters or pandemics when resources are limited, specialized critical care triage protocols may be implemented:

• Uses exclusion criteria to determine ICU admission eligibility 3
• Employs scoring systems like SOFA (Sequential Organ Failure Assessment) to prioritize patients 3
• Considers factors such as likelihood of survival and resource requirements

Implementation Considerations

When implementing triage systems:

• Regular training of triage nurses is essential to minimize under-triage, which poses a significant risk to patient safety 4
• Under-triage rates should ideally be kept below 5-10% to ensure patient safety 4
• Over-triage (assigning higher acuity than needed) is less dangerous but wastes resources

Pitfalls and Limitations

Important considerations when using triage systems:

• Triage accuracy varies significantly between providers and systems 5
• Neither START nor SALT has demonstrated high sensitivity or specificity for predicting clinical outcomes in some studies 2
• Triage decisions should be periodically reassessed as patient conditions can change rapidly
• Special populations (pediatric, geriatric, pregnant) may require modified triage approaches
• Cultural and language barriers can affect accurate triage assessment

Effective triage is fundamental to emergency department operations and directly impacts patient outcomes by ensuring timely care based on clinical need rather than arrival time.