Glasgow Coma Scale
Encyclopedia
Glasgow Coma Scale or GCS is a neurological
scale
that aims to give a reliable, objective way of recording the conscious state of a person for initial as well as subsequent assessment. A patient is assessed against the criteria of the scale, and the resulting points give a patient score between 3 (indicating deep unconsciousness) and either 14 (original scale) or 15 (the more widely used modified or revised scale).
GCS was initially used to assess level of consciousness after head injury
, and the scale is now used by first aid
, EMS
, and doctors
as being applicable to all acute medical and trauma patients. In hospitals it is also used in monitoring chronic patients in intensive care.
The scale was published in 1974 by Graham Teasdale and Bryan J. Jennett, 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
. A similar scale, the Rancho Los Amigos Scale
is used to assess the recovery of traumatic brain injury
patients.
The scale comprises three tests: eye
, verbal and motor
responses. The three values separately as well as their sum are considered. The lowest possible GCS (the sum) is 3 (deep coma
or death
), while the highest is 15 (fully awake person).
Generally, brain injury is classified as:
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 e.g. 'E1c' where 'c' = closed, or 'V1t' where t = tube. 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'. Often the 1 is left out, so the scale reads Ec or Vt.
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.
and lack of prognostic utility. Although there is not an agreed upon alternative, the general suggestion is a simplified motor scale
be used instead.
Neurology
Neurology is a medical specialty dealing with disorders of the nervous system. Specifically, it deals with the diagnosis and treatment of all categories of disease involving the central, peripheral, and autonomic nervous systems, including their coverings, blood vessels, and all effector tissue,...
scale
Scale (ratio)
The scale ratio of some sort of model which represents an original proportionally is the ratio of a linear dimension of the model to the same dimension of the original. Examples include a 3-dimensional scale model of a building or the scale drawings of the elevations or plans of a building. In such...
that aims to give a reliable, objective way of recording the conscious state of a person for initial as well as subsequent assessment. A patient is assessed against the criteria of the scale, and the resulting points give a patient score between 3 (indicating deep unconsciousness) and either 14 (original scale) or 15 (the more widely used modified or revised scale).
GCS was initially used to assess level of consciousness after head injury
Head injury
Head injury refers to trauma of the head. This may or may not include injury to the brain. However, the terms traumatic brain injury and head injury are often used interchangeably in medical literature....
, and the scale is now used by first aid
First aid
First aid is the provision of initial care for an illness or injury. It is usually performed by non-expert, but trained personnel to a sick or injured person until definitive medical treatment can be accessed. Certain self-limiting illnesses or minor injuries may not require further medical care...
, EMS
Emergency medical services
Emergency medical services are a type of emergency service dedicated to providing out-of-hospital acute medical care and/or transport to definitive care, to patients with illnesses and injuries which the patient, or the medical practitioner, believes constitutes a medical emergency...
, and doctors
Physician
A physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...
as being applicable to all acute medical and trauma patients. In hospitals it is also used in monitoring chronic patients in intensive care.
The scale was published in 1974 by Graham Teasdale and Bryan J. Jennett, professors of neurosurgery at the University of Glasgow
University of Glasgow
The University of Glasgow is the fourth-oldest university in the English-speaking world and one of Scotland's four ancient universities. Located in Glasgow, the university was founded in 1451 and is presently one of seventeen British higher education institutions ranked amongst the top 100 of the...
's Institute of Neurological Sciences at the city's Southern General Hospital
Southern General Hospital
The Southern General Hospital is a large teaching hospital with an acute operational bed complement of approximately 900 beds. The Hospital is located in Linthouse in the south west of Glasgow, Scotland, United Kingdom and provides a comprehensive range of acute and related clinical...
.
GCS is used as part of several ICU scoring systems
ICU scoring systems
-Adult scoring systems:* APACHE II was designed to provide a morbidity score for a patient. It is useful to decide what kind of treatment or medicine is given...
, including APACHE II
APACHE II
APACHE II is a severity-of-disease classification system , one of several ICU scoring systems...
, SAPS II
SAPS II
SAPS II is a severity of disease classification system . Its name stands for "Simplified Acute Physiology Score", and is one of several ICU scoring systems.-Application:...
, and SOFA
SOFA Score
The Sequential Organ Failure Assessment score, or just SOFA score, is used to track a patient's status during the stay in an intensive care unit . It is one of several ICU scoring systems....
, to assess the status of the central nervous system
Central nervous system
The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...
. A similar scale, the Rancho Los Amigos Scale
Rancho Los Amigos Scale
The Rancho Los Amigos Scale is a medical scale used to assess individuals after a closed head injury, including traumatic brain injury, based on cognitive and behavioural presentations as they emerge from coma...
is used to assess the recovery of traumatic brain injury
Traumatic brain injury
Traumatic brain injury , also known as intracranial injury, occurs when an external force traumatically injures the brain. TBI can be classified based on severity, mechanism , or other features...
patients.
Elements of the scale
| 1 | 2 | 3 | 4 | 5 | 6 | |
|---|---|---|---|---|---|---|
| Eyes | Does not open eyes | Opens eyes in response to painful stimuli | Opens eyes in response to voice | Opens eyes spontaneously | N/A | N/A |
| Verbal | Makes no sounds | Incomprehensible sounds | Utters inappropriate words | Confused, disoriented | Oriented, converses normally | N/A |
| Motor | Makes no movements | Extension to painful stimuli (decerebrate response) | Abnormal flexion to painful stimuli (decorticate response) | Flexion / Withdrawal to painful stimuli | Localizes painful stimuli | Obeys commands |
The scale comprises three tests: eye
Visual perception
Visual perception is the ability to interpret information and surroundings from the effects of visible light reaching the eye. The resulting perception is also known as eyesight, sight, or vision...
, verbal and motor
Motor skill
A motor skill is a learned sequence of movements that combine to produce a smooth, efficient action in order to master a particular task. The development of motor skill occurs in the motor cortex, the region of the cerebral cortex that controls voluntary muscle groups.- Development of motor skills...
responses. The three values separately as well as their sum are considered. The lowest possible GCS (the sum) is 3 (deep coma
Coma
In medicine, a coma is a state of unconsciousness, lasting more than 6 hours in which a person cannot be awakened, fails to respond normally to painful stimuli, light or sound, lacks a normal sleep-wake cycle and does not initiate voluntary actions. A person in a state of coma is described as...
or death
Death
Death is the permanent termination of the biological functions that sustain a living organism. Phenomena which commonly bring about death include old age, predation, malnutrition, disease, and accidents or trauma resulting in terminal injury....
), while the highest is 15 (fully awake person).
Best eye response (E)
There are 4 grades starting with the most severe:- No eye opening
- Eye opening in response to painPainPain is an unpleasant sensation often caused by intense or damaging stimuli such as stubbing a toe, burning a finger, putting iodine on a cut, and bumping the "funny bone."...
. (Patient responds to pressure on the patient’s fingernail bed; if this does not elicit a response, supraorbitalSupraorbital ridgeThe supraorbital ridge, or brow ridge, refer to a bony ridge located above the eye sockets of all primates. In Homo sapiens sapiens the eyebrows are located on their lower margin.Other terms in use are:* supraorbital arch...
and sternal pressure or rub may be used.) - Eye opening to speech. (Not to be confused with an awaking of a sleeping person; such patients receive a score of 4, not 3.)
- Eyes opening spontaneously
Best verbal response (V)
There are 5 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)
- Confused. (The patient responds to questions coherently but there is some disorientation and confusion.)
- OrientedOrientation (mental)Orientation is a function of the mind involving awareness of three dimensions: time, place and person. Problems with orientation lead to disorientation, and can be due to various conditions, from delirium to intoxication...
. (Patient responds coherently and appropriately to questions such as the patient’s name and age, where they are and why, the year, month, etc.)
Best motor response (M)
There are 6 grades starting with the most severe:- No motor response
- Extension to pain (abductionAbduction (kinesiology)Abduction, in functional anatomy, is a movement which draws a limb away from the median plane of the body. It is thus opposed to adduction.-Upper limb:* of arm at shoulder ** Supraspinatus** Deltoid* of hand at wrist...
of arm, external rotation of shoulder, supinationSupinationSupination is a position of either the forearm or foot; in the forearm when the palm faces anteriorly, or faces up . Supination in the foot occurs when a person appears "bow-legged" with their weight supported primarily on the anterior of their feet.The hand is supine in the anatomical position...
of forearm, extensionExtension (kinesiology)In kinesiology, extension is a movement of a joint that results in increased angle between two bones or body surfaces at a joint. Extension usually results in straightening of the bones or body surfaces involved. For example, extension is produced by extending the flexed elbow. Straightening of...
of wrist, decerebrate response) - Abnormal flexion to pain (adductionAdductionAdduction is a movement which brings a part of the anatomy closer to the middle sagittal plane of the body. It is opposed to abduction.-Upper limb:* of arm at shoulder ** Subscapularis** Teres major** Pectoralis major** Infraspinatus...
of arm, internal rotation of shoulder, pronationPronationIn anatomy, pronation is a rotational movement of the forearm at the radioulnar joint, or of the foot at the subtalar and talocalcaneonavicular joints. For the forearm, when standing in the anatomical position, pronation will move the palm of the hand from an anterior-facing position to a...
of forearm, flexionFlexionIn anatomy, flexion is a position that is made possible by the joint angle decreasing. The skeletal and muscular systems work together to move the joint into a "flexed" position. For example the elbow is flexed when the hand is brought closer to the shoulder...
of wrist, decorticate response) - Flexion/Withdrawal to pain (flexionFlexionIn anatomy, flexion is a position that is made possible by the joint angle decreasing. The skeletal and muscular systems work together to move the joint into a "flexed" position. For example the elbow is flexed when the hand is brought closer to the shoulder...
of elbow, supinationSupinationSupination is a position of either the forearm or foot; in the forearm when the palm faces anteriorly, or faces up . Supination in the foot occurs when a person appears "bow-legged" with their weight supported primarily on the anterior of their feet.The hand is supine in the anatomical position...
of forearm, flexionFlexionIn anatomy, flexion is a position that is made possible by the joint angle decreasing. The skeletal and muscular systems work together to move the joint into a "flexed" position. For example the elbow is flexed when the hand is brought closer to the shoulder...
of wrist when supra-orbital pressure applied ; pulls part of body away when nailbed pinched) - Localizes to pain. (Purposeful movements towards painful stimuli; e.g., hand crosses mid-line and gets above clavicleClavicleIn human anatomy, the clavicle or collar bone is a long bone of short length that serves as a strut between the scapula and the sternum. It is the only long bone in body that lies horizontally...
when supra-orbital pressure applied.) - Obeys commands. (The patient does simple things as asked.)
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, with GCS ≤ 8
- Moderate, GCS 9 - 12
- Minor, GCS ≥ 13.
Tracheal intubation
Tracheal intubation
Tracheal intubation, usually simply referred to as intubation, is the placement of a flexible plastic or rubber tube into the trachea to maintain an open airway or to serve as a conduit through which to administer certain drugs...
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 e.g. 'E1c' where 'c' = closed, or 'V1t' where t = tube. 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'. Often the 1 is left out, so the scale reads Ec or Vt.
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
Pediatric Glasgow Coma Scale
The Paediatric Glasgow Coma Scale is the equivalent of the Glasgow Coma Scale used to assess the mental state of adult patients. As many of the assessments for an adult patient would not be appropriate for infants, the scale was modified slightly...
, a separate yet closely related 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 (including the Glasgow unit where the original work was done) 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.
Controversy
The GSC has come under pressure from some researchers that take issue with the scale's issues, such as poor inter-rater reliabilityInter-rater reliability
In statistics, inter-rater reliability, inter-rater agreement, or concordance is the degree of agreement among raters. It gives a score of how much homogeneity, or consensus, there is in the ratings given by judges. It is useful in refining the tools given to human judges, for example by...
and lack of prognostic utility. Although there is not an agreed upon alternative, the general suggestion is a simplified motor scale
Simplified motor scale
Simplified Motor Scales refer to a neurological evaluation that is designed to provide a meaningful, objective prognostic evaluation of an individual...
be used instead.
See also
- Blantyre Coma ScaleBlantyre Coma ScaleThe Blantyre Coma Scale is a modification of the Pediatric Glasgow Coma Scale, designed to assess malarial coma in children.It was designed by Drs. Terrie Taylor and Malcolm Molyneux in 1987, and named for the Malawian city of Blantyre, site of the Blantyre Malaria Project.-Using the scale:The...
- Rancho Los Amigos ScaleRancho Los Amigos ScaleThe Rancho Los Amigos Scale is a medical scale used to assess individuals after a closed head injury, including traumatic brain injury, based on cognitive and behavioural presentations as they emerge from coma...
- Paediatric Glasgow Coma Scale
- Revised Trauma ScoreRevised Trauma ScoreThe Revised Trauma Score is a tool for on-site triage for Multiple Casualty Incidents. Its superior efficiency is due to both speed and objectivity. It is designed to provide a comprehensive assessment for medical professionals of any field....