Escala de Coma de Glasgow

Glasgow Coma Scale (GCS)

The Glasgow Coma Scale sums three components: Eye opening (1–4), Verbal response (1–5), and Motor response (1–6), totaling 3–15. Interpretation: 13–15 mild, 9–12 moderate, ≤8 severe (definite criterion for orotracheal intubation to protect the airway). Example: eyes open spontaneously (4) + oriented speech (5) + obeys commands (6) = GCS 15. A patient who opens eyes to pain (2), produces incomprehensible sounds (2), and shows abnormal flexion (3) = GCS 7 — severe.

Clinical context

Developed by Teasdale and Jennett in 1974 at the Institute of Neurological Sciences in Glasgow, it became the universal language for level of consciousness in TBI, ICU, emergency departments, EMS, and neurosurgery. Used to monitor coma progression and guide intubation. Limitations: it is unreliable in intubated, sedated, or aphasic patients (verbal component impossible — annotate as T). Pediatric and neonatal variants exist. Complementary scales: NIHSS for stroke, FOUR score in ICU (assesses brainstem and intubated patients).

FAQ

Why is GCS ≤8 the intubation threshold? Because below that score, airway protective reflexes are typically lost, with risk of bronchoaspiration and respiratory failure.

How to score an intubated patient? Document the verbal component as 1T and report the score as, e.g., E3 V1T M5 = 9T. Some services use the FOUR score instead.

Does GCS predict prognosis? Partially. Low scores correlate with worse outcomes in TBI, but the score alone does not replace neuroimaging, pupillary exam, and clinical evolution.

What is the minimum score? 3 (1+1+1) — never zero. A score of 3 indicates deep coma with no eye opening, no verbal response, and no motor response.