Glasgow Coma Scale

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Glasgow Coma Scale
MeSH D015600
LOINC 35088-4

The Glasgow Coma Scale [1] (GCS) is a clinical scale used to reliably measure a person's level of consciousness after a brain injury.

Contents

The GCS assesses a person based on their ability to perform eye movements, speak, and move their body. These three behaviours make up the three elements of the scale: eye, verbal, and motor. A person's GCS score can range from 3 (completely unresponsive) to 15 (responsive). This score is used to guide immediate medical care after a brain injury (such as a car accident) and also to monitor hospitalised patients and track their level of consciousness.

Lower GCS scores are correlated with higher risk of death. However, the GCS score alone should not be used on its own to predict the outcome for an individual person with brain injury.

Scoring

The Glasgow Coma Scale is used for people above the age of two and is composed of three tests: eye, verbal, and motor responses. The scores for each of these tests are indicated in the table below.

Glasgow Coma Scale [2]
TestNot Testable (NT): Examples123456
Eye
(ocular response)		Severe trauma to the eyes, enucleation Does not open eyesOpens eyes in response to pain [lower-alpha 1] Opens eyes in response to voiceOpens eyes spontaneouslyN/AN/A
Verbal
(oral response)		 Intubation, non-oral language disability, linguistic barrier Makes no soundsIncomprehensible soundsInappropriate wordsConfused and disoriented, but able to answer questionsOriented to time, person, and place, converses normallyN/A
Motor
(motoric response)		 Paralysis/hemiparesis (acquired causes such as post-stroke, post-neurological injury; congenital/innate such as cerebral palsy)Makes no movementsAbnormal extension (decerebrate posture) [lower-alpha 2] Abnormal flexion (decorticate posture)Flexion / Withdrawal from painful stimuliMoves to localise painObeys commands

The Glasgow Coma Scale is reported as the combined score (which ranges from 3 to 15) and the score of each test (E for eye, V for Verbal, and M for Motor). For each test, the value should be based on the best response that the person being examined can provide. [6]

For example, if a person obeys commands only on their right side, they get a 6 for motor. The scale also accounts for situations that prevent appropriate testing (Not Testable). When specific tests cannot be performed, they must be reported as "NT" and the total score is not reported.

The results are reported as the Glasgow Coma Score (the total points from the three tests) and the individual components. As an example, a person's score might be: GCS 12, E3 V4 M5. Alternatively, if a patient was intubated, their score could be GCS E2 V NT M3.

Pediatric scoring

Children below the age of two struggle with the tests necessary for assessment of the Glasgow Coma Scale. As a result, a version for children has been developed, and is outlined below.

Pediatric Glasgow Coma Scale [7]
Not Testable (NT)123456
EyeEx: severe trauma to the eyesDoes not open eyesOpens eyes in response to painOpens eyes in response to soundOpens eyes spontaneouslyN/AN/A
VerbalEx: IntubationMakes no soundsMoans in response to painCries in response to painIrritable/CryingCoos/BabblesN/A
MotorEx: ParalysisMakes no movementsExtension to painful stimuli (decerebrate response)Abnormal flexion to painful stimuli (decorticate response)Withdraws from painWithdraws from touchMoves spontaneously and purposefully

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". Patients with scores of 3 to 8 are usually considered to be in a coma. [8] 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). 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 (when the verbal performance of even a healthy child would be expected to be poor). Consequently, the Paediatric Glasgow Coma Scale was developed for assessing younger children.

History

Pre-GCS assessment

During the 1960s, assessment and management of head injuries became a topic of interest. The number of head injuries was rapidly increasing, in part because of increased use of motorised transport. Also, doctors recognised that after head trauma, many patients had poor recovery. This led to a concern that patients were not being assessed or medically managed correctly. [10] Appropriate assessment is a critical step in medical management for several reasons. First, a reliable assessment allows doctors to provide the appropriate treatment. Second, assessments let doctors keep track of how a patient is doing, and intervene if the patient is doing worse. Finally, a system of assessment allows researchers to define categories of patients. This makes it possible to determine which treatments are best for different types of patients.

A number of assessments for head injury ("coma scales") were developed, though none were widely adopted. Of 13 scales that had been published by 1974, all involved linear scales that defined levels of consciousness. [11] [12] [13] [14] [15] [16] [17] [18] [19] These scales posed two problems. First, levels of consciousness in these scales were often poorly defined. This made it difficult for doctors and nurses to evaluate head injury patients. Second, different scales used overlapping and obscure terms that made communication difficult. [20]

Origin

In this setting, Bryan Jennett and Graham Teasdale of the University of Glasgow Medical School began work on what became the Glasgow Coma Scale. Based on their experiences, they aimed to make a scale satisfying several criteria. First, it needed to be simple, so that it could be performed without special training. Second, it needed to be reliable, so that doctors could be confident in the results of the scale. Third, the scale needed to provide important information for managing a patient with a head injury. [20]

Their work resulted in the 1974 publication of the first iteration of the GCS. [1] The original scale involved three exam components (eye movement, motor control, and verbal control). These components were scored based on clearly defined behavioural responses. Clear instructions for administering the scale and interpreting results were also included. The original scale is identical to the current scale except for the motor assessment. The original motor assessment included only five levels, combining "flexion" and "abnormal flexion". This was done because Jennett and Teasdale found that many people struggled in distinguishing these two states. [1]

Updates to the Glasgow Coma Scale

In 1976, Teasdale updated the motor component of the Glasgow Coma Scale to differentiate flexion movements. [2] This was because trained personnel could reliably distinguish flexion movements. Further research also demonstrated that normal and abnormal flexion have different clinical outcomes. [21] As a result, the six-point motor scale is now considered the standard.

Teasdale did not originally intend to use the sum score of the GCS components. [20] However, later work demonstrated that the sum of the GCS components, or the Glasgow Coma Score, had clinical significance. Specifically, the sum score was correlated with outcome (including death and disability). [21] As a result, the Glasgow Coma Score is used in research to define patient groups. It is also used in clinical practice as shorthand for the full scale.

Adoption in clinical use

The Glasgow Coma Scale was initially adopted by nursing staff in the Glasgow neurosurgical unit. [20] Especially following a 1975 nursing publication, it was adopted by other medical centres. [22] True widespread adoption of the GCS was attributed to two events in 1978. [20] First, Tom Langfitt, a leading figure in neurological trauma, wrote an editorial in Journal of Neurosurgery strongly encouraging neurosurgical units to adopt the GCS score. [23] Second, the GCS was included in the first version of Advanced Trauma Life Support (ATLS), which expanded the number of centres where staff were trained in performing the GCS. [24]

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. [25] 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. [26] Although the inter-rater reliability of these newer scores has been slightly higher than that of the GCS, they have not yet gained consensus as replacements. [27]

See also

Related Research Articles

<span class="mw-page-title-main">Head injury</span> Serious trauma to the cranium

A head injury is any injury that results in trauma to the skull or brain. The terms traumatic brain injury and head injury are often used interchangeably in the medical literature. Because head injuries cover such a broad scope of injuries, there are many causes—including accidents, falls, physical assault, or traffic accidents—that can cause head injuries.

The Paediatric Glasgow Coma Scale or the Pediatric Glasgow Coma Score or simply PGCS is the equivalent of the Glasgow Coma Scale (GCS) used to assess the level of consciousness of child patients. As many of the assessments for an adult patient would not be appropriate for infants, the Glasgow Coma Scale was modified slightly to form the PGCS. As with the GCS, the PGCS comprises three tests: eye, verbal and motor responses. The three values separately as well as their sum are considered. The lowest possible PGCS is 3 whilst the highest is 15. The pediatric GCS is commonly used in emergency medical services.

The AVPU scale is a system by which a health care professional can measure and record a patient's level of consciousness. It is mostly used in emergency medicine protocols, and within first aid.

Abnormal posturing is an involuntary flexion or extension of the arms and legs, indicating severe brain injury. It occurs when one set of muscles becomes incapacitated while the opposing set is not, and an external stimulus such as pain causes the working set of muscles to contract. The posturing may also occur without a stimulus. Since posturing is an important indicator of the amount of damage that has occurred to the brain, it is used by medical professionals to measure the severity of a coma with the Glasgow Coma Scale and the Pediatric Glasgow Coma Scale.

There are several scoring systems in intensive care units (ICUs) today.

The Revised Trauma Score (RTS) is a physiologic scoring system based on the initial vital signs of a patient. A lower score indicates a higher severity of injury.

A coma scale is a system to assess the severity of coma. There are several such systems:

Concussion grading systems are sets of criteria used in sports medicine to determine the severity, or grade, of a concussion, the mildest form of traumatic brain injury. At least 16 such systems exist, and there is little agreement among professionals about which is the best to use. Several of the systems use loss of consciousness and amnesia as the primary determinants of the severity of the concussion.

Post-traumatic amnesia (PTA) is a state of confusion that occurs immediately following a traumatic brain injury (TBI) in which the injured person is disoriented and unable to remember events that occur after the injury. The person may be unable to state their name, where they are, and what time it is. When continuous memory returns, PTA is considered to have resolved. While PTA lasts, new events cannot be stored in the memory. About a third of patients with mild head injury are reported to have "islands of memory", in which the patient can recall only some events. During PTA, the patient's consciousness is "clouded". Because PTA involves confusion in addition to the memory loss typical of amnesia, the term "post-traumatic confusional state" has been proposed as an alternative.

<span class="mw-page-title-main">Bryan Jennett</span> British neurosurgeon

William Bryan Jennett was a British neurosurgeon, a faculty member at the University of Glasgow Medical School, and the first full-time chair of neurosurgery in Scotland. He was the co-developer of the assessment tool known as the Glasgow Coma Scale and made advancements in the care of patients with brain injuries. in 1972, Jennett and the neurologist Fred Plum coined the term vegetative state.

The National Institutes of Health Stroke Scale, or NIH Stroke Scale (NIHSS), is a tool used by healthcare providers to objectively quantify the impairment caused by a stroke and aid planning post-acute care disposition, though was intended to assess differences in interventions in clinical trials. The NIHSS was designed for the National Institute of Neurological Disorders and Stroke (NINDS) Recombinant Tissue Plasminogen Activator (rt-PA) for Acute Stroke Trial and was first published by neurologist Dr. Patrick Lyden and colleagues in 2001. Prior to the NIHSS, during the late 1980s, several stroke-deficit rating scales were in use.

<span class="mw-page-title-main">Trauma in children</span> Medical condition

Trauma in children, also known as pediatric trauma, refers to a traumatic injury that happens to an infant, child or adolescent. Because of anatomical and physiological differences between children and adults the care and management of this population differs.

The FOUR Score is a clinical grading scale designed for use by medical professionals in the assessment of patients with impaired level of consciousness. It was developed by Dr. Eelco F.M. Wijdicks and colleagues in Neurocritical care at the Mayo Clinic in Rochester, Minnesota. "FOUR" in this context is an acronym for "Full Outline of UnResponsiveness".

Simplified motor scales (SMS) refer to a neurological evaluation that is designed to provide a meaningful, objective prognostic evaluation of an individual. SMS have been proposed as alternatives that would improve upon the Glasgow Coma Scale challenges of being confusing, unreliable and unnecessarily complex.

Pupillometry, the measurement of pupil size and reactivity, is a key part of the clinical neurological exam for patients with a wide variety of neurological injuries. It is also used in psychology.

Pain stimulus is a technique used by medical personnel for assessing the consciousness level of a person who is not responding to normal interaction, voice commands or gentle physical stimuli. It forms one part of a number of neurological assessments, including the first aid based AVPU scale and the more medically based Glasgow Coma Scale.

The Glasgow Outcome Score (GOS) is a scale of patients with brain injuries, such as cerebral traumas that groups victims by the objective degree of recovery. The first description was in 1975 by Jennett and Bond.

The Disability Rating Scale (DRS) was developed as a way to track a traumatic brain injury (TBI) patient from 'Coma to Community'. The scale was used to rate the effects of injury and decide how long recovery might take. The rating gives insight into the cognitive impairment of the individual with the TBI.

Sir Graham Michael Teasdale is an English neurosurgeon and the co-developer of the neurologic assessment tool known as the Glasgow Coma Scale. He is an Honorary Professor in Mental Health and Wellbeing in the Institute of Health and Wellbeing at the University of Glasgow Medical School.

A pediatric concussion, also known as pediatric mild traumatic brain injury (mTBI), is a head trauma that impacts the brain capacity. Concussion can affect functional, emotional, cognitive and physical factors and can occur in people of all ages. Symptoms following after the concussion vary and may include confusion, disorientation, lightheadedness, nausea, vomiting, blurred vision, loss of consciousness (LOC) and environment sensitivity. Concussion symptoms may vary based on the type, severity and location of the head injury. Concussion symptoms in infants, children, and adolescents often appear immediately after the injury, however, some symptoms may arise multiple days following the injury leading to a concussion. The majority of pediatric patients recover from the symptoms within one month following the injury. 10-30% of children and adolescents have a higher risk of a delayed recovery or of experiencing concussion symptoms that are persisting.

References

Citations

  1. 1 2 3 4 Teasdale G, Jennett B (July 1974). "Assessment of coma and impaired consciousness. A practical scale". The Lancet . 2 (7872): 81–4. doi:10.1016/s0140-6736(74)91639-0. PMID   4136544.
  2. 1 2 Teasdale G, Jennett B (1976). "Assessment and prognosis of coma after head injury". Acta Neurochirurgica. 34 (1–4): 45–55. doi:10.1007/BF01405862. PMID   961490. S2CID   32325456.
  3. ↑ Iankova A (December 2006). "The Glasgow Coma Scale: clinical application in emergency departments". Emergency Nurse. 14 (8): 30–5. doi:10.7748/en2006.12.14.8.30.c4221. PMID   17212177.
  4. ↑ Teasdale G (2015). "Glasgow Coma Scale: Do it this way" (PDF). Institute of Neurological Sciences NHS Greater Glasgow and Clyde.
  5. ↑ "Glasgow Coma Scale". Geeky Medics. 31 October 2018. Retrieved 20 January 2023.
  6. ↑ Glynn M (2012). Hutchinson's clinical methods (23rd ed.). India: Elsevier. ISBN   9788131232880.[ page needed ]
  7. ↑ Borgialli DA, Mahajan P, Hoyle JD, Powell EC, Nadel FM, Tunik MG, et al. (August 2016). "Performance of the Pediatric Glasgow Coma Scale Score in the Evaluation of Children With Blunt Head Trauma". Academic Emergency Medicine. 23 (8): 878–84. doi: 10.1111/acem.13014 . PMID   27197686.
  8. ↑ Bickley LS, Szilagyi PR, Hoffman RM (2017). Bates' Guide to Physical Examination and History Taking, Twelfth Edition. Wolters Kluwer. p. 791. ISBN   978-1-4698-9341-9.
  9. ↑ "Resources Data: Glasgow Coma Scale" (PDF). Centers for Disease Control and Prevention. U.S. Department of Health & Human Services. Retrieved 20 January 2023.
  10. ↑ Mckissock W, Taylor J, Bloom W, Till K (1960). "Extradural Hæmatoma". The Lancet. 276 (7143): 167–172. doi:10.1016/s0140-6736(60)91322-2. ISSN   0140-6736.
  11. ↑ Bouzarth WF (January 1968). "Neurosurgical watch sheet for craniocerebral trauma". The Journal of Trauma. 8 (1): 29–31. doi:10.1097/00005373-196801000-00004. PMID   5293834.
  12. ↑ Bozzamarrubini ML (1 April 1964). "Resuscitation treatment of the different degrees of unconsciousness". Acta Neurochirurgica. 12 (2): 352–65. doi:10.1007/BF01402103. PMID   14293386. S2CID   38678828.
  13. ↑ Fischgold H, Schwartz BA, Dreyfus-Brisac C (February 1959). "Indicateur de l'état de présence et tracés électroencéphalographiques dans le sommeil nembutalique" [Indicator of the state of responsiveness and electroencephalographic recordings during nembutal-induced sleep]. Electroencephalography and Clinical Neurophysiology (in French). 11 (1): 23–33. doi:10.1016/0013-4694(59)90004-5. PMID   13630229.
  14. ↑ Fisher CM (1969). "The neurological examination of the comatose patient". Acta Neurologica Scandinavica. 45 (S36): 5–56. doi: 10.1111/j.1600-0404.1969.tb04785.x . PMID   5781179. S2CID   68037509.
  15. ↑ Mollaret P, Goulon M (July 1959). "[The depassed coma (preliminary memoir)]". Revue Neurologique. 101: 3–15. PMID   14423403.
  16. ↑ "Acute Injuries of the Head. By G. F. Rowbotham. Fourth edition. 9⅝ × 6¾ in. Pp. 604, with 271 illustrations. 1964. Edinburgh: E. & S. Livingstone Ltd. £5". British Journal of Surgery. 52 (2): 158. February 1965. doi:10.1002/bjs.1800520221.
  17. ↑ Ommaya AK, Sadowsky D (September 1966). "A system of coding medical data for punched-card machine retrieval. II. As applied to head injuries". The Journal of Trauma. 6 (5): 605–17. doi:10.1097/00005373-196609000-00006. PMID   5928631.
  18. ↑ Overgaard J, Hvid-Hansen O, Land AM, Pedersen KK, Christensen S, Haase J, et al. (September 1973). "Prognosis after head injury based on early clinical examination". Lancet. 2 (7830): 631–5. doi:10.1016/S0140-6736(73)92477-X. PMID   4125617.
  19. ↑ Plum F, Posner JB (1972). "The diagnosis of stupor and coma". Contemporary Neurology Series. 10: 1–286. PMID   4664014.
  20. 1 2 3 4 5 Mattei TA, Teasdale GM (February 2020). "The Story of the Development and Adoption of the Glasgow Coma Scale: Part I, The Early Years". World Neurosurgery. 134: 311–322. doi:10.1016/j.wneu.2019.10.193. PMID   31712114. S2CID   207955750.
  21. 1 2 Teasdale G, Murray G, Parker L, Jennett B (1979). "Adding up the Glasgow Coma Score". In Brihaye J, Clarke PR, Loew F, Overgaard J (eds.). Proceedings of the 6th European Congress of Neurosurgery. Vol. 28. Vienna: Springer Vienna. pp. 13–6. doi:10.1007/978-3-7091-4088-8_2. ISBN   978-3-7091-4090-1. PMID   290137.{{cite book}}: |journal= ignored (help)
  22. ↑ Teasdale G, Galbraith S, Clarke K (June 1975). "Acute impairment of brain function-2. Observation record chart". Nursing Times. 71 (25): 972–3. PMID   1144086.
  23. ↑ Langfitt TW (May 1978). "Measuring the outcome from head injuries". Journal of Neurosurgery. 48 (5): 673–8. doi:10.3171/jns.1978.48.5.0673. PMID   641547.
  24. ↑ Collicott PE, Hughes I (March 1980). "Training in advanced trauma life support". JAMA. 243 (11): 1156–9. doi:10.1001/jama.1980.03300370030022. PMID   7359667.
  25. ↑ Green SM (November 2011). "Cheerio, laddie! Bidding farewell to the Glasgow Coma Scale". Annals of Emergency Medicine. 58 (5): 427–30. doi:10.1016/j.annemergmed.2011.06.009. PMID   21803447.
  26. ↑ Iyer VN, Mandrekar JN, Danielson RD, Zubkov AY, Elmer JL, Wijdicks EF (August 2009). "Validity of the FOUR score coma scale in the medical intensive care unit". Mayo Clinic Proceedings. 84 (8): 694–701. doi:10.4065/84.8.694. PMC   2719522 . PMID   19648386.
  27. ↑ Fischer M, Rüegg S, Czaplinski A, Strohmeier M, Lehmann A, Tschan F, et al. (2010). "Inter-rater reliability of the Full Outline of UnResponsiveness score and the Glasgow Coma Scale in critically ill patients: a prospective observational study". Critical Care. 14 (2): R64. doi: 10.1186/cc8963 . PMC   2887186 . PMID   20398274.

General sources

Notes

  1. ↑ A peripheral pain stimulus, such as squeezing the lunula area of the person's fingernail, is more effective than a central stimulus such as a trapezius squeeze, as the latter tends to make the patient close their eyes and grimace instead. [3]
  2. ↑ Different guidelines report different evaluation of abnormal extension. While some sources indicate extension at the elbow is sufficient, [4] other sources use the language "decerebrate posturing". [5] It is important to note that the original publication of the Glasgow Coma Scale explicitly avoided the term "decerebrate extension" because it implied specific anatomical findings. [1]
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