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Glasgow Coma Scale

Assessment of Level of Consciousness

Interpretation

The Glasgow Coma Scale (GCS) was developed and standardized for the assessment and classification of the severity of Traumatic Brain Injury (TBI). Outside the context of TBI, however, it is widely used as a descriptive tool for level of consciousness, assisting clinical decision-making.

In TBI — ATLS and Brain Trauma Foundation

Score Classification
13 – 15 Mild TBI
9 – 12 Moderate TBI
3 – 8 Severe TBI

In other clinical scenarios — descriptive use (scale not standardized for this purpose)

Score Classification
15 Consciousness intact on behavioral examination
13 – 14 Mild depression of consciousness
9 – 12 Moderate depression of consciousness
3 – 8 Severe depression of consciousness

Note: The GCS threshold of ≤ 8 is widely used in guidelines as a reference point for considering advanced airway management, but is not an absolute rule — the decision must be individualized. The application of the GCS may be limited by sedation, prior intubation, aphasia, and pre-existing neurological deficits. When a component cannot be assessed, the total sum is invalid; report the components separately with appropriate notation (e.g. VNT for verbal not testable). It is recommended to always record the total score together with the component notation (e.g. GCS 11 = E3V3M5).

References

  • 1. Teasdale G, Jennett B. Assessment of coma and impaired consciousness: a practical scale. Lancet. 1974;2(7872):81–84. PubMed ↗
  • 2. Teasdale G, et al. The Glasgow Coma Scale at 40 years: standing the test of time. Lancet Neurol. 2014;13(8):844–854. PubMed ↗
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