Glasgow Coma Scale

Glasgow Coma Scale(GCS)
Definition:
The Glasgow Coma Scale is the most widely used scoring system used in quantifying level of consciousness, especially after a head injury, in which scoring is determined by three factors: amount of eye opening, verbal responsiveness, and motor responsiveness. Graham Teasdale and Bryan J. Jennett first developed the Glasgow Coma Scale in 1974. At the University of Glasgow, these neurosurgery professors continued to develop important work in the field of head traumas, publishing Management of Head Injuries in 1981.
It is used primarily because it is simple, has a relatively high degree of interobserver(meaning different people scale it consistently) reliability and because it correlates well with outcome following severe brain injury.
There are limitations to its use. If the patient has an endotracheal tube in place, they cannot talk. For this reason, many prefer to document the score by its individual components; so a patient with a Glasgow Coma Score of 15 would be documented as follows: E4 V5 M6. An intubated patient would be scored as E4 Vt M6. Of these individual factors, the best motor response is probably the most significant.
Other factors which alter the patients level of consciousness interfere with the scale's ability to acurately reflect the severity of a traumatic brain injury. So, shock, hypoxemia, drug use, alcohol intoxication, metabolic disturbances may alter the GCS independently of the brain injury. Obviously, a patient with a spinal cord injury will make the motor scale invalid, and severe orbital trauma may make eye opening impossible to assess (Ec). The GCS also has limited utility in children, particularly those less than 36 months.
Consequently, both doctors and nurses regularly use the Glasgow Coma Scale multiple times on individual patients to determine their evolving needs and changing conditions.
E + M + V = 3 to 15
90% less than or equal to 8 are in coma
Less than or equal to 8 at 6 hours - 50% die
8 is the critical score
9-11 = moderate severity
Greater than or equal to 12 = minor injury
Coma is defined as: (1) not opening eyes, (2) not obeying commands, and (3) not uttering understandable words.
Mild (13-15)
Moderate Disability (9-12)
Severe Disability (3-8)
Vegetative State (Less Than 3):
Sleep wake cycles
Aruosal, but no interaction with environment
No localized response to pain
Persistent Vegetative State:
Vegetative state lasting longer than one month
Individual elements as well as the sum of the score are important. Hence, the score is expressed in the form "GCS 9 = E2 V4 M3 at 07:35".
The GCS has limited applicability to children, especially below the age of 36 months (where the verbal performance of even a healthy child would be expected to be poor). Consequently the Pediatric Glasgow Coma Scale, a separate yet closely related scale, was developed for assessing younger children.
Glasgow Coma Scale: While the 15 point scale is the predominant one in use, this is in fact a modification and is more correctly referred to as the Modified Glasgow Coma Scale. The original scale was a 14 point scale, omitting the category of ‘withdrawal to pain'. Some centres still use this older scale, but most (including the Glasgow unit where the original work was done) have adopted the modified one.
http://www.patient.co.uk/doctor/Glasgow-Coma-Scale-(GCS).htm