Revised Trauma Score (RTS)

Clinical Overview & History

The Revised Trauma Score (RTS) is a physiological triage scoring system developed in 1989 by Champion et al. to assess injury severity and predict survival probability in trauma patients. It was designed as an update to the older Trauma Score (TS) to simplify clinical parameters and improve inter-rater reliability.

RTS has two distinct applications in trauma care:

1. Triage RTS (T-RTS): A simplified version used by pre-hospital emergency medical service (EMS) personnel for rapid field triage. The scores (0 to 4) for Glasgow Coma Scale (GCS), Systolic Blood Pressure (SBP), and Respiratory Rate (RR) are summed directly to yield a score from 0 to 12.
2. Physiological RTS (RTS): A weighted version primarily used for research, quality control, and epidemiological assessments of trauma systems. It applies regression-derived weights to the coded values.

Pathophysiology and Scoring Criteria

Severe physical trauma disrupts the body's homeostatic mechanisms. The RTS focuses on the three critical organ systems whose failure leads to immediate mortality: the brain (neurological), the cardiovascular system (perfusion), and the lungs (gas exchange).

The variables are coded from 0 (severely compromised) to 4 (normal):

• Glasgow Coma Scale (GCS): Reflects central nervous system integrity and traumatic brain injury.
  • $13 - 15 o$ 4 points
  • $9 - 12 o$ 3 points
  • $6 - 8 o$ 2 points
  • $4 - 5 o$ 1 point
  • $3 o$ 0 points
• Systolic Blood Pressure (SBP): Reflects hemodynamic stability and systemic perfusion. Hypotension indicates hemorrhagic or neurogenic shock.
  • $> 89\text{ mmHg} o$ 4 points
  • $76 - 89\text{ mmHg} o$ 3 points
  • $50 - 75\text{ mmHg} o$ 2 points
  • $1 - 49\text{ mmHg} o$ 1 point
  • $0\text{ mmHg} o$ 0 points
• Respiratory Rate (RR): Evaluates airway compromise, chest wall trauma, or neurological respiratory drive. Both tachypnea ($> 29/\text{min}$) and bradypnea are penalized.
  • $10 - 29\text{ breaths/min} o$ 4 points
  • $> 29\text{ breaths/min} o$ 3 points
  • $6 - 9\text{ breaths/min} o$ 2 points
  • $1 - 5\text{ breaths/min} o$ 1 point
  • $0\text{ breaths/min} o$ 0 points

Formula & Scoring Interpretation

The unweighted Triage RTS (T-RTS) is calculated as:

The weighted Physiological RTS is calculated using the following formula:

$\text{RTS} = 0.9368(\text{GCS}_{\text{coded}}) + 0.7326(\text{SBP}_{\text{coded}}) + 0.2908(\text{RR}_{\text{coded}})$

Where the coded values represent the points (0 to 4) assigned to each variable. The Triage RTS (T-RTS) is interpreted as follows:

• Triage RTS = 12: Represents normal physiology (probability of survival $\approx 99%$).
• Triage RTS le 11: Indicates physiological compromise. In the field, any score of 11 or lower mandates rapid transport to a designated Level 1 or Level 2 trauma center.
• Triage RTS le 3: Associated with a survival probability of less than 10%, representing extreme physiological distress or cardiovascular arrest.

Step-by-Step Clinical Scenario

Consider a clinical case: A 28-year-old male is brought to the emergency department following a high-speed motor vehicle collision. Upon initial assessment:

• Glasgow Coma Scale is calculated as 8 (eye opening to pain, incomprehensible sounds, abnormal flexion) (Coded GCS = 2).
• Systolic Blood Pressure is $82\text{ mmHg}$ (Coded SBP = 3).
• Respiratory Rate is $32\text{ breaths/min}$ (Coded RR = 3).

Let's calculate both scores:

• Triage RTS (T-RTS):

$\text{T-RTS} = 2 + 3 + 3 = 8\text{ points}$

A T-RTS of 8 represents severe physiological derangement and signals that the patient requires immediate resuscitation and transfer to a major trauma center.

• Physiological RTS:

$\text{RTS} = 0.9368(2) + 0.7326(3) + 0.2908(3) = 1.8736 + 2.1978 + 0.8724 = 4.9438$

An RTS value of $4.94$ corresponds to a predicted survival probability of approximately $60% - 70%$. This value is used by trauma registries to analyze outcomes and audit system performance.

Clinical Utility and Trauma System Audit

RTS is a key component of the TRISS (Trauma and Injury Severity Score) methodology, which combines physiological injury (RTS), anatomical injury (Injury Severity Score, or ISS), and patient age to calculate survival probability. TRISS allows hospitals to compare their actual mortality rates with expected rates to evaluate the quality of trauma care.

⚠️ Medical Disclaimer: This calculator is for educational and reference purposes only. It is not intended to diagnose, treat, or cure any disease, and should not be used as a substitute for professional clinical judgment.