GCS scores level of consciousness from eye, verbal, and motor responses, and is best known in respiratory care as the classic trigger for deciding whether a patient needs their airway protected with intubation.
Mild / minimal impairment.
Moderate impairment.
Severe — classic intubation threshold for airway protection.
Intubation isn't only for lung failure. A patient who can't protect their own airway — from vomiting, secretions, or the tongue obstructing it — needs a tube to prevent aspiration, regardless of how well their lungs work.
A GCS of 8 or below is the classic teaching threshold for considering intubation to protect the airway, though it's a guide rather than an absolute rule.
Eye opening (1–4), verbal response (1–5), and motor response (1–6), summed to a total of 3–15. The motor score carries the most prognostic weight.
13–15 is mild impairment, 9–12 is moderate, and 8 or below is severe.