GAP Trauma Score Calculator

Overview

Calculates the Glasgow Coma Scale, Age and systolic blood Pressure trauma score. The calculator is intended to make the underlying equation transparent while preserving the requirement for clinical assessment and source-data verification.

Clinical Significance

Higher scores indicate lower predicted mortality in the derivation cohorts. Common bands are 19–24 low risk, 11–18 intermediate risk and 3–10 high risk, but local validation and clinical context are essential.

When to Use

• Stratify adult trauma mortality risk using immediately available variables.
• Use after an initial reliable GCS and blood-pressure assessment.
• Combine with anatomical injury and clinical judgement.

How It Is Calculated

• GAP = GCS + 3 points if age under 60 + SBP points: 6 for ≥120, 4 for 60–119 and 0 for <60 mmHg.
• MedicalC validates required values, applies the stated equation and rounds only the displayed result.
• Review intermediate measurements and assumptions whenever the result appears discordant with the clinical picture.

Interpretation

• Higher scores indicate lower predicted mortality in the derivation cohorts. Common bands are 19–24 low risk, 11–18 intermediate risk and 3–10 high risk, but local validation and clinical context are essential.
• Interpret trends only when the same technique, units and clinical conditions are reasonably comparable.

Worked Example

Enter the required measurements in the displayed units. MedicalC applies: GAP = GCS + 3 points if age under 60 + SBP points: 6 for ≥120, 4 for 60–119 and 0 for <60 mmHg. Confirm the result against the original observations before using it in a clinical decision.

Patient Considerations

• Consider age, body size, pregnancy, organ support, medication, rhythm, ventilation, measurement conditions and acute physiological change where relevant.
• Use the earliest reliable values for prognostic trauma scores unless the score definition specifies otherwise.
• Repeat calculations only when a changed result could influence care and the source data remain valid.

Limitations

• Sedation, intoxication and intubation can invalidate GCS.
• The score does not incorporate anatomical injury or mechanism.
• Performance varies between trauma systems and populations.

Clinical Pearls

• Treat the calculator as a transparent equation, not an autonomous recommendation.
• Record the exact time and method of important measurements.
• Resolve a clinically implausible result by checking inputs before assuming unusual physiology.

Common Mistakes

• Entering values in the wrong unit.
• Combining measurements obtained at different clinical time points.
• Applying a published threshold outside its validated population or setting.
• Allowing a score to delay urgent treatment.

Evidence Base

The calculator implements the stated published or established relationship. Principal source: Kondo Y, et al. Revised trauma scoring system to predict in-hospital mortality in the emergency department: GAP score. Crit Care. 2011.

References

1. Kondo Y, et al. Revised trauma scoring system to predict in-hospital mortality in the emergency department: GAP score. Crit Care. 2011. — Primary publication, authoritative guideline or recognised specialty source.