By Philip Neuwirth, BS, MICP, CCEMTP, FP-C
Despite the research that states, “Glasgow Coma Scale scoring should not be considered accurate”, (Bledsoe, Casey, Feldman, et al), it’s unfortunately here to stay. Listed below are some of the advantages and disadvantages of using GCS as noted by Life in the Fast Lane, Aug, 2014). I have been using GCS for nearly 30 years, but generally after the patient has been delivered to the emergency department and while documenting the case. The main purpose for writing this article is to stop prehospital clinicians from converting a GCS to a single number. When reporting a GCS to a trauma team or physician, always state the component numbers, such as E1, V1, M2. If you are unable to assess a component of the GCS, state, the letter and “not testable”. Please take the time to view the video below, which reviews the assessment and documentation of using the GCS.
- Most widely recognized of all conscious level scoring systems in the world
- Has face validity (looks like it should work)
- Reproducible (this is controversial, in one study 38% of the cases the GCS scores were the same and in 33% of cases the scores varied with more than two points)
- Skewed towards motor score, which is good since this is the most reliable measure of short-term prognosis in TBI
- The distinction between a motor score of 2, 3 and 4 is a very useful clinical indicator of the severity of TBI, and the area of brain function that has been affected
- Correlates with adverse neurological outcomes such as brain injury, neurosurgical intervention, and mortality
Problems with the use of GCS
- Unreliable in patients in the middle range of 9-12
- Motor Score does not factor in unilateral pathology
- Not originally intended to be converted into a single score — the components (E4,V5, M6) are more important than the total score
- Does not incorporate brain-stem reflexes
- The same GCS score will predict different TBI mortality depending on the components
- GCS of 4 with the components E1+V1+M2 predicts a mortality rate of 48%
- GCS of 4 with the components E2+V1+M1 predicts a mortality rate of 19%
- Grossly predictive but cannot accurately predict outcomes in individual patients (on par with weather presenters predicting rain or WBC predicting appendicitis!)
Because our PCR requires we document a GCS, and many doctors request it, we might as well use it to the best of our ability. The following video is published on the GCS website www.glasgowcomascale.org. It’s a great review and follows the New Glasgow Structured Approach to Assessment.
Glasgow Coma Scale (GCS) | LITFL: Life in the Fast Lane Medical Blog lifeinthefastlane.com › Critical Care Compendium, Aug 2, 2014
Bledsoe BE, Casey MJ, Feldman J, et al. Glasgow Coma Scale scoring is often inaccurate. Prehosp Disaster Med. 2015;30(1):46–53.
Teasdale, G., Sir. (2014). THE GLASGOW STRUCTURED APPROACH to ASSESSMENT of the GLASGOW COMA SCALE. Retrieved August 01, 2016, from http://www.glasgowcomascale.org/