What is the best approach to assess injury severity and guide patient management in cases of trauma using trauma scores such as Injury Severity Score (ISS) and Revised Trauma Score (RTS)?

Optimal Approach to Trauma Scoring for Injury Severity Assessment and Patient Management

The most effective approach to trauma scoring combines physiologic parameters from Step One triage criteria (GCS, SBP, respiratory rate) with anatomic criteria from Step Two, rather than relying on complex calculated scores like RTS alone. 1

Trauma Scoring Systems Overview

Physiologic Assessment (Step One)

The primary assessment should focus on these key physiologic parameters:

• Glasgow Coma Scale (GCS):

  • GCS <14 is a significant predictor of mortality
  • Patients with GCS <14 show reduced mortality when transported to Level I trauma centers (OR: 0.7; CI = 0.6-0.9) 1

• Systolic Blood Pressure (SBP):

  • SBP <90 mmHg indicates shock
  • Critical threshold for triage decisions

• Respiratory Rate:

  • <10 or >29 breaths per minute indicates severe injury
  • Abnormal respiratory rate is associated with reduced mortality when treated at Level I trauma centers (OR: 0.6; CI = 0.4-0.8) 1

Anatomic Assessment (Step Two)

If physiologic parameters appear normal, proceed to anatomic criteria:

• Penetrating injuries to head, neck, torso, and extremities proximal to elbow/knee
• Flail chest
• Two or more proximal long-bone fractures
• Crushed, degloved, or mangled extremity
• Amputation proximal to wrist/ankle
• Pelvic fractures
• Open or depressed skull fracture
• Paralysis 1

Recommended Scoring Approach

For Initial Field Triage:

Use individual physiologic parameters (GCS, SBP, respiratory rate) rather than calculated scores. The 2006 Decision Scheme specifically removed RTS due to:

• Complex calculation making it unwieldy in the field
• Rare actual use by EMS providers for decision-making
• Redundancy with individual parameters already assessed 1

For Hospital Assessment and Outcome Prediction:

TRISS (Trauma and Injury Severity Score) shows superior performance with:

• Highest predictive value for mortality (AUC: 0.93, sensitivity 97.1%, specificity 76.7%) 2
• Better sensitivity (94.7%) and specificity (76.6%) than ISS alone 3

For ICU Admission Decisions:

NISS (New Injury Severity Score) performs best with AUC value of 0.81 2

Common Pitfalls and Caveats

1. Overreliance on single scoring systems:

   • Using RTS alone has limitations with 21% missing data in large studies 4
   • Physiologic criteria alone had sensitivity of 0.7 for severe injury (ISS >15) 1
   • Anatomic criteria alone had sensitivity of only 0.5 1

2. Calculation complexity:

   • RTS calculation is unwieldy in emergency situations
   • The formula (GCS×0.9 + SBP×0.7 + respiratory rate×0.3) is time-consuming 1

3. Undertriage risk:

   • Relying solely on physiologic parameters may miss severe injuries
   • Combining physiologic and anatomic criteria improves sensitivity to 0.8 1

4. Missing data problems:

   • When RTS cannot be fully calculated, the combination of GCS-Motor with SBP shows comparable predictive power (AUROC 0.85) with fewer missing cases 4

Practical Implementation

1. Begin with rapid assessment of physiologic parameters (GCS, SBP, respiratory rate)
2. If any abnormalities present, transport to highest level trauma center available
3. If physiologic parameters normal, assess anatomic criteria
4. For hospital-based outcome prediction, calculate TRISS when data available
5. For quality improvement purposes, document all parameters for retrospective analysis

This approach balances practical field application with evidence-based outcome prediction, prioritizing rapid identification of patients needing the highest level of trauma care.