Glasgow Coma Scale (GCS) Calculator

Standardised tool for assessing level of consciousness following head injury or for neurological assessment.

Important Disclaimer: This calculator is for informational purposes only and should be used by qualified healthcare professionals. GCS assessment requires proper training and should be used alongside other clinical assessments. Always follow your local clinical protocols and guidelines.
Assessment Parameters
Opens eyes spontaneously
Opens eyes when asked to do so
Opens eyes in response to painful stimulus
Does not open eyes
Fully oriented to person, place, and time
Answers questions but confused
Random or exclamatory articulated speech
Moaning, groaning, no recognisable words
No verbal response
Patient unable to make verbal response due to endotracheal tube or tracheostomy
Follows simple commands
Purposeful movement towards painful stimulus
Pulls away from pain
Decorticate posturing (abnormal flexion)
Decerebrate posturing (abnormal extension)
No motor response
About Glasgow Coma Scale

The Glasgow Coma Scale (GCS) is a neurological scale developed by Graham Teasdale and Bryan Jennett at the University of Glasgow in 1974. It aims to provide a reliable and objective way to record the conscious state of a person, particularly after traumatic brain injury.

The GCS assesses three aspects of responsiveness:

  • Eye opening (E) - scored from 1-4
  • Verbal response (V) - scored from 1-5
  • Motor response (M) - scored from 1-6

Scores can range from 3 (deep coma) to 15 (fully awake and alert). The individual scores for E, V, and M should be noted separately as well as the total score.

For intubated patients, the verbal score cannot be assessed, and is often recorded as 'T' (for tube). In these cases, the score should be reported as E/M (e.g., "GCS 8T = E3M5").

Clinical Usage Guidelines

When to Use GCS

  • Initial assessment of patients with head injury
  • Monitoring neurological status in critical care settings
  • Assessing deterioration or improvement in neurological conditions
  • Triage decisions in emergency situations
  • Standardised communication between healthcare professionals

Limitations of GCS

  • Limited utility in intubated patients (verbal component cannot be assessed)
  • Affected by factors like intoxication, sedation, or dementia
  • Not designed for assessment of young children
  • Inter-observer variability may occur, especially with less experienced users
  • Motor response is the most reliable component, but loss of verbal or eye components reduces sensitivity

FAQs about Glasgow Coma Scale

Frequency depends on the clinical situation:

  • For unstable patients or those at risk of neurological deterioration: Every 15-30 minutes
  • In acute situations with stable GCS: Every 1-2 hours
  • For monitored patients with stable condition: Every 4 hours
  • In recovery phase with consistent scores: Once per shift

Local protocols may vary between hospitals and departments, and the frequency should be adjusted based on the patient's condition and trend in GCS scores.

For intubated patients, the verbal component cannot be tested. Current best practice recommends:

  • Record the score as "E_M_V T" where T indicates intubation (e.g., "E4M6VT")
  • Some clinicians record a derived score (e.g., "10T" for E4M6VT), though this approach is discouraged as it loses information
  • Never estimate or guess what the verbal score might be
  • Focus on tracking changes in the eye and motor scores

When possible, the GCS should be assessed prior to intubation to establish a baseline.

Normal flexion (withdrawal, score of 4):

  • Rapid withdrawal from painful stimulus
  • Arm pulls away/bends at elbow
  • No abnormal wrist flexion or adduction
  • Appears purposeful - like withdrawing from pain

Abnormal flexion (decorticate posturing, score of 3):

  • Slow, stereotyped movement
  • Adduction of arm
  • Wrist and fingers flex
  • May be accompanied by internal rotation of shoulder
  • Not a direct withdrawal from stimulus

Distinguishing between these responses requires training and careful observation.

GCS has several limitations that can affect its accuracy:

  • Pre-existing conditions: Dementia, learning disabilities, hearing impairment, or aphasia can affect verbal responses
  • Facial trauma or orbital swelling: May prevent accurate assessment of eye opening
  • Spinal cord injury: May affect motor responses
  • Intoxication: Alcohol or drugs can temporarily decrease GCS not due to brain injury
  • Medications: Sedatives, paralytics, and analgesics affect responses
  • Paediatric patients: Standard GCS is not designed for young children (use paediatric versions instead)

Always document any factors that might influence GCS assessment alongside the score.

References

  1. Teasdale G, Jennett B. (1974). Assessment of coma and impaired consciousness. A practical scale. Lancet, 2(7872):81-4.
  2. National Institute for Health and Care Excellence (NICE). (2019). Head injury: assessment and early management (CG176).
  3. Teasdale G, Maas A, Lecky F, Manley G, Stocchetti N, Murray G. (2014). The Glasgow Coma Scale at 40 years: standing the test of time. Lancet Neurol, 13(8):844-54.
  4. Royal College of Physicians and Surgeons of Glasgow. Glasgow Coma Scale - Official website.