Glasgow Coma Scale (GCS) Calculator

The Glasgow Coma Scale (GCS) is a neurological scale used to assess and quantify consciousness level in patients with brain injury, altered mental status, or critical illness. Developed in 1974, GCS evaluates three components: Eye opening (1-4 points), Verbal response (1-5 points), and Motor response (1-6 points). Total scores range from 3 (deep coma/death) to 15 (fully awake). GCS is the most widely used consciousness assessment tool worldwide, validated for trauma, stroke, and critical care.

GCS interpretation: 15 = Normal, fully conscious. 13-14 = Mild brain injury/dysfunction. 9-12 = Moderate brain injury. 8 or less = Severe brain injury, coma. GCS <=8 typically indicates need for airway protection and intubation ("GCS 8, intubate"). Serial GCS monitoring tracks neurological improvement or deterioration. Declining GCS suggests worsening brain injury, increased intracranial pressure, or metabolic derangement. GCS also predicts outcomes: lower scores correlate with higher mortality and worse functional recovery.

Eye Opening (E): Spontaneous (4), to voice (3), to pain (2), none (1). Assesses arousal and brainstem function. Verbal Response (V): Oriented (5), confused (4), inappropriate words (3), incomprehensible sounds (2), none (1). Evaluates cognitive function and language. Motor Response (M): Obeys commands (6), localizes pain (5), withdraws from pain (4), flexion to pain/decorticate (3), extension to pain/decerebrate (2), none (1). Tests motor pathways and brainstem integrity. Record as E+V+M (e.g., GCS 9 = E2V3M4).

GCS should be assessed in: head trauma patients, altered mental status, suspected stroke, post-cardiac arrest, drug overdose, metabolic encephalopathy, post-operative neurosurgery, any critically ill patient. Initial GCS establishes baseline severity. Serial assessments (every 15-60 minutes initially, then as clinically indicated) detect neurological changes. Document best response achieved. Factors affecting GCS: sedation, paralysis, intubation (cannot assess verbal), orbital swelling (cannot assess eyes), aphasia, language barriers. Note confounders when recording GCS.

GCS limitations: Verbal component cannot be assessed in intubated patients (use "T" suffix, e.g., GCS 10T). Eye opening unreliable with severe facial trauma/swelling. Doesn't assess brainstem reflexes (pupil response, corneal reflex). Less sensitive for detecting focal neurological deficits. Cultural/language barriers affect verbal assessment. Sedation and paralytic medications invalidate GCS. Not designed for children <2 years (use pediatric GCS modification). Despite limitations, GCS remains gold standard for consciousness assessment due to simplicity, reproducibility, and universal acceptance.