Glasgow coma scale
| Glasgow coma scale |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] ; Associate Editor(s)-in-Chief: Pratik Bahekar, MBBS [2]
Overview
The 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, emergency medical services, and doctors as being applicable to all acute medical and trauma patients. In hospitals it is also used in monitoring chronic patients in the 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.
Elements of the scale
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 (the sum) is 3 (deep coma or death), while the highest is 15 (fully awake person).
Eye response (E)
There are four grades starting with the most severe:
- No eye opening
- Eye opening in response to pain stimulus. (a peripheral pain stimulus, such as squeezing the lunula area of the patient's fingernail is more effective than a central stimulus such as a trapezius squeeze, due to a grimacing effect)[1]
- Eye opening to speech. (Not to be confused with the awakening of a sleeping person; such patients receive a score of 4, not 3.)
- Eyes opening spontaneously
Verbal response (V)
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)
- Confused (The patient responds to questions coherently but there is some disorientation and confusion)
- Orientation (Patient responds coherently and appropriately to questions such as the patient’s name and age, where they are and why, the year, month, etc.)
Motor response (M)
There are six grades:
- No motor response
- Extension to pain (extensor posturing: Abduction of arm, external rotation of shoulder, supination of forearm, extension of wrist, decerebrate response)
- Abnormal flexion to pain (flexor posturing: Adduction of arm, internal rotation of shoulder, pronation of forearm, flexion of wrist, decorticate response)
- Flexion/Withdrawal to pain (flexion of elbow, supination of forearm, flexion 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 clavicle when supra-orbital pressure applied)
- Obeys commands (The patient does simple things as asked.)
Summary
| 1 | 2 | 3 | 4 | 5 | 6 | |
|---|---|---|---|---|---|---|
| Eye | 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 |
GCS is caliberated by addition of all three scores, giving a range of 3-15.
The lower scores correspond to poorer prognosis:
Interpretation
| GCS | Category | Patient presentation |
|---|---|---|
| 8-15 | Somnolence | Sleepy, easy to wake |
| 8-15 | Stupor | Hypnoid, hard to wake |
| ≥13 | Mild | |
| 9-12 | Moderate | |
| <8 | Unconscious | |
| 7-8 | Coma Grade I | Light Coma |
| 5-6 | Coma Grade II | Light Coma |
| 4 | Coma Grade III | Deep Coma |
| 3 | Coma Grade IV | Deep Coma |
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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".
Brain injury is classified as:
- GCS < 8-9: Severe Head Injury
- GCS 8 or 9–12: Moderate Head Injury
- Minor, GCS ≥ 13: Mild Head Injury
(Adapted from: Advanced Trauma Life Support: Course for Physicians, American College of Surgeons, 1993)[3]
Generally when a patient is in a decline of their GCS score, the nurse or medical staff should assess the cranial nerves and determine which of the twelve have been affected.
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.
Disclaimer
Based on motor responsiveness, verbal performance, and eye opening to appropriate stimuli, the Glascow Coma Scale was designed and should be used to assess the depth and duration coma and impaired consciousness. This scale helps to gauge the impact of a wide variety of conditions such as acute brain damage due to traumatic and/or vascular injuries or infections, metabolic disorders (e.g., hepatic or renal failure, hypoglycemia, diabetic ketosis) etc.[4]
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 GCS has come under pressure from some researchers that take issue with the scale's issues, such as poor inter-rater reliability and lack of prognostic utility.[5] Although there is not an agreed upon alternative, newer scores such as the Simplified motor scale and FOUR score have also been developed as improvements to the GCS.[6] While inter-rater reliability of these newer scores have been slightly higher than the GCS, they were not significant enough to gain consensus as a replacement.
Acknowledgements
The content on this page was first contributed by Editor-In-Chief: C. Michael Gibson, M.S., M.D. [3]
See also
External links
- Website to calculate the Glasgow Coma Scale
- Glasgow+Coma+Scale at the US National Library of Medicine Medical Subject Headings (MeSH)
- An Android app to calculate GCS / PGCS
References
- ↑ "The Glasgow Coma Scale: clinical application in Emergency Departments". Emergency Nurse. 14 (8): 30–5. 2006.
- ↑ "Glasgow Coma Scale". Retrieved 8 March 2014. Text "Mass Casualties " ignored (help)[dead link]
- ↑ "http://www.bt.cdc.gov/masscasualties/pdf/glasgow-coma-scale.pdf" (PDF). External link in
|title=(help) - ↑ "http://www.bt.cdc.gov/masscasualties/pdf/glasgow-coma-scale.pdf" (PDF). External link in
|title=(help) - ↑ Green, S. M. (2011). Cheerio, Laddie! Bidding Farewell to the Glasgow Coma Scale. Annals of emergency medicine, 58(5), 427_430. Elsevier Inc. doi:10.1016/j.annemergmed.2011.06.009
- ↑ Iver, VN; Mandrekar, JN; Danielson, RD; Zubkov, AY; Elmer, JL; Wijdicks, EF (2009). "Validity of the FOUR score coma scale in the medical intensive care unit". Mayo Clinic Proceedings. 84 (8): 694–701. PMID 19648386.