Happy 50th birthday Glasgow Coma Scale
Myron Yaster MD, Shawn Jackson MD PhD, Ethan Sanford MD, Justin L. Lockman MD MSEd
“In July, 1974, Teasdale and Jennet published a scale for the assessment of coma and impaired consciousness1 called the Glasgow Coma Scale (GCS). Before the introduction of the GCS, level of consciousness was reported in vague and ambiguous terms (e.g., comatose, subcomatose, stuporous, or obtunded), which led to inaccurate communication among health-care providers, delays in the detection of clinical changes, and avoidable mortality and morbidity. The scale aimed to provide an objective framework for describing levels of consciousness by assessing three domains of responsiveness, incorporating eye, motor, and verbal components that are currently scored with 4, 6, and 5 categories, respectively. Lower scores represent a worse response. A few years after the scale was introduced, clinicians recognized2 that adding up the individual component scores into a GCS sum score (ranging from 3 to 15) provided a useful means for aggregating information, primarily for research purposes.”
In today’s PAAD, Manley and Maas3 review the Glasgow Coma Scale on its 50th birthday and discuss its value and limitations. The article is only 1 and half pages long and is definitely worth reading in its entirety AND we have no desire to make the PAAD longer than the article itself! Here are some of the highlights. Myron Yaster MD
Original article
Manley GT, Maas AI. The Glasgow Coma Scale at 50: looking back and forward. Lancet. 2024 Aug 24;404(10454):734-735. doi: 10.1016/S0140-6736(24)01596-4. Epub 2024 Aug 14. PMID: 39153494.
Original article
Teasdale G, Jennett B. Assessment of coma and impaired consciousness. A practical scale. Lancet. 1974 Jul 13;2(7872):81-4. doi: 10.1016/s01a40-6736(74)91639-0. PMID: 4136544.
The Glasgow coma scale is easy to use and has stood the test of time, particularly for traumatic brain injury (TBI) patients. It is used on initial assessment and for serial evaluations and assists in clinical decision making, triage for admission and discharge, and to classify injury severity. Pediatric specific GCS tools were later developed for those under the age of 2 with an adaptation from 19864 having been validated by the Pediatric Emergency Care Applied Research Network5. There are many easy-to-use online calculators that incorporate adult and pediatric scoring options like https://www.mdcalc.com/calc/3702/pediatric-glasgow-coma-scale-pgcs. We always encourage use of a calculator, because we’ve found over years of experience that “eyeballing” the GCS never seems to match an actual calculated score.
Criticisms of GCS have focused on deviations from recommended procedures in assessing GCS (see above re: calculator) and on utilization of the GCS sum score rather than individual components as was initially intended.6 “The sum score used to classify TBI severity as mild (GCS score 13–15), moderate (GCS score 9–12), or severe (GCS score ≤8) is thought to be too simplistic and inaccurate for predicting long-term outcomes. The GCS is a tool for use in individual patients, and the scores of each of its components should be reported to inform a deeper characterization of the patient's condition.”3 To improve the Glasgow coma score, the NIH has proposed adding pupillary reactivity, blood biomarkers, and advanced imaging to more accurately assess coma and its therapies. These additions may improve accuracy in prognostic capabilities, but should not diminish the utility of GCS in rapidly communicating the current mental status of a patient presenting for care.
The Glasgow coma scale is a remarkable success story in standardizing assessment across healthcare – and it has survived the test of time…Happy 50th birthday, GCS! Send your thoughts and comments to Myron at myasterster@gmail.com who will post in a Friday Reader Response.
PS from Myron: An alternative to the Glasgow coma scale often used by first responders because of its ease is the Alert, Verbal, Pain, Unresponsive (AVPU) scale.7 The AVPU scale is included in the American Heart Association’s Pediatric Advanced Life Support guidelines and can be used for all patients with altered levels of consciousness not just in trauma. A paper in the August issue of Pediatrics compares the AVPU to the Glasgow Coma Scale.7 We’ll review it in the near future.
References
1. Teasdale G, Jennett B. Assessment of coma and impaired consciousness. A practical scale. Lancet (London, England) 1974;2(7872):81-4. (In eng). DOI: 10.1016/s0140-6736(74)91639-0.
2. Teasdale G, Jennett B, Murray L, Murray G. Glasgow coma scale: to sum or not to sum. Lancet (London, England) 1983;2(8351):678. (In eng). DOI: 10.1016/s0140-6736(83)92550-3.
3. Manley GT, Maas AI. The Glasgow Coma Scale at 50: looking back and forward. Lancet (London, England) 2024;404(10454):734-735. (In eng). DOI: 10.1016/s0140-6736(24)01596-4.
4. James HE. Neurologic evaluation and support in the child with an acute brain insult. Pediatric annals 1986;15(1):16-22. (In eng). DOI: 10.3928/0090-4481-19860101-05.
5. Borgialli DA, Mahajan P, Hoyle JD, Jr., et al. Performance of the Pediatric Glasgow Coma Scale Score in the Evaluation of Children With Blunt Head Trauma. Academic emergency medicine : official journal of the Society for Academic Emergency Medicine 2016;23(8):878-84. (In eng). DOI: 10.1111/acem.13014.
6. Reith FCM, Lingsma HF, Gabbe BJ, Lecky FE, Roberts I, Maas AIR. Differential effects of the Glasgow Coma Scale Score and its Components: An analysis of 54,069 patients with traumatic brain injury. Injury 2017;48(9):1932-1943. (In eng). DOI: 10.1016/j.injury.2017.05.038.
7.Ramgopal S, Horvat CM, Cash RE, Pelletier JH, Martin-Gill C, Macy ML. Comparing AVPU and Glasgow Coma Scales Among Children Seen by Emergency Medical Services. Pediatrics 2024;154(2). DOI: 10.1542/peds.2024-066168.