How often have you watched a hospital drama where someone says ‘the patient has a GCS of x’? What does GCS mean, why is such a coding system used and who invented it?
It is 40 years since the GCS scale was first published in 1974 by Graham Teasdale and Bryan J. Jennett.
Both were neurosurgeons at the University of Glasgow’s Institute of Neurological Sciences at Glasgow Southern General Hospital and so, understandably, ‘GCS’ stands for the Glasgow Coma Scale.
This scale was created to give a reliable and objective way of recording the conscious state of a patient and is set against three assessed criteria that give a resulting score between 3 (deeply unconsciousness) and 15 (fully conscious).
Although originally used to assess head trauma it is now applied to all acute medical and trauma patients including patients in intensive care.
The scale comprises three tests, firstly on both eyes (E), secondly responses to verbal commands (V) and thirdly motor responses (M).
Calculations on all three areas are performed and the resulting sum used to calculate the final ‘score’.
For the eyes (E) the lowest score is attained by someone not opening their eyes (1) and progresses to eye opening in response to a painful stimulus (2), eye opening to verbal instructions (3) and lastly eyes opening spontaneously (4).
For the second criterion, verbal response (V), there are five grades starting with the most severe, no verbal response progressing through incomprehensible sounds, inappropriate words, confusion (the patient responds to questions coherently but there is some confusion) to ‘oriented’ where the patient responds coherently and appropriately to questions and is able to give their name, age or date of birth, where they are, what has happened to them etc.
The last criterion is a motor response (M) going from no movement, extension of a limb/rotation of a joint, abnormal response to pain etc. to ‘obeys commands’ where the patient does what they are asked.
If you place the scale in terms of severity, a GCS of less than 8-9 is severe, one somewhere between 9-12 ‘moderate’ and greater than 13 ‘minor’.
There is a variation of the Glasgow Coma Scale that can be applied to children, especially below the age of 3 years (you would not expect for example to be able to assess verbal performance of even a healthy child at this age).
As you can see the Glasgow Coma Scale has stood the test of time and is now internationally recognised as an efficient assessment of consciousness.