The Glasgow Coma Scale is a neurologicalscale which aims to give a reliable and objective way of recording the state of a person's consciousness for initial as well as subsequent assessment. A person is assessed against the criteria of the scale, and the resulting points give a person's score between 3 and either 14 or 15. GCS was used to assess a person's level of consciousness after a head injury, and the scale is now used by emergency medical services, nurses, and physicians as being applicable to all acute medical and trauma patients. In hospitals, it is also used in monitoring patients in intensive care units. The scale was published in 1974 by Graham Teasdale and Bryan J. Jennett, both professors of neurosurgery at the University of Glasgow's Institute of Neurological Sciences at the city's Southern General Hospital. GCS is used as part of several ICU scoring systems, including APACHE II, SAPS II, and SOFA, to assess the status of the central nervous system. The initial indication for use of the GCS was serial assessments of people with traumatic brain injury and coma for at least six hours in the neurosurgical ICU setting, though it is commonly used throughout hospital departments. The similar Rancho Los Amigos Scale is used to assess the recovery of traumatic brain injury. GCS was updated following a review of the helpfulness and usefulness of the scale from clinicians. It was decided that several things required updating, like the EyeResponse element, meaning that instead of responding to "Painful Stimuli" being regarded as a 2, a person that opens their eyes in response to pressure is now considered a 2 in the Eye Response element.
Elements of the scale
Note that a motor response in any limb is acceptable. The scale is composed of three tests: eye, verbal and motor responses. The three values separately as well as their sum are considered. The lowest possible GCS is 3, while the highest is 15.
Eye response (E)
There are four grades starting with the most severe:
There are five grades starting with the most severe:
No verbal response
Incomprehensible sounds. Moaning but no words.
Inappropriate words. Random or exclamatory articulated speech, but no conversational exchange. Speaks words but no sentences.
Confused. The person responds to questions coherently but there is some disorientation and confusion.
Oriented. Person responds coherently and appropriately to questions such as the person’s name and age, where they are and why, the year, month, etc.
Motor response (M)
There are six grades:
No motor response
Decerebrate posturing accentuated by pain
Decorticate posturing accentuated by pain
Withdrawal from pain
Localizes to pain
Obeys commands
Interpretation
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". Generally, brain injury is classified as:
Severe, GCS < 8–9
Moderate, GCS 8 or 9–12
Minor, GCS ≥ 13.
Tracheal intubation and severe facial/eye swelling or damage make it impossible to test the verbal and eye responses. In these circumstances, the score is given as 1 with a modifier attached. Often the 1 is left out, so the scale reads Ec or Vt. A composite might be "GCS 5tc". This would mean, for example, eyes closed because of swelling = 1, intubated = 1, leaving a motor score of 3 for "abnormal flexion". The GCS has limited applicability to children, especially below the age of 36 months. Consequently, the Paediatric Glasgow Coma Scale was developed for assessing younger children.
Revisions
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 "abnormal flexion". Some centres still use this older scale, but most have adopted the modified one.
The Rappaport Coma/Near Coma Scale made other changes.
Meredith W., Rutledge R, Fakhry SM, EMery S, Kromhout-Schiro S have proposed calculating the verbal score based on the measurable eye and motor responses.
The most widespread revision has been the Simplified Motor and Verbal Scales which shorten the respective sections of the GCS without loss of accuracy.
The GCS for intubated people is scored between 2 and 10 as the verbal component falls away
Controversy
The GCS has come under pressure from some researchers who take issue with the scale's poor inter-rater reliability and lack of prognostic utility. Although there is no agreed-upon alternative, newer scores such as the Simplified motor scale and FOUR score have also been developed as improvements to the GCS. Although the inter-rater reliability of these newer scores has been slightly higher than that of the GCS, they have not gained consensus as replacements.
