Glasgow Coma Scale (GCS)

Components matter as much as the total. GCS 8 with E2 V2 M4 (eyes-to-pain, sounds, withdraws) is a different patient than GCS 8 with E1 V1 M6 (no eye, no verbal, obeys commands — possibly locked-in or sedated). Always document the breakdown, not just the total. The motor score is the most prognostic component and the most resilient to confounders.

GCS ≤ 8 is the airway threshold. Conventional teaching is that patients with GCS ≤ 8 lose protective airway reflexes and warrant definitive airway management (endotracheal intubation). Like all rules of thumb it has exceptions — sedated, post-ictal, or hypoglycemic patients may have low GCS but be expected to recover quickly. Clinical judgment integrates trajectory, cause, and other factors.