Gill M, Steele R, Windemuth R, et al: “A comparison of five simplified scales to the out-of-hospital Glasgow Coma Scale for the prediction of traumatic brain injury outcomes.” Academic Emergency Medicine. 13(9):968-973, 2006.
The Science
The researchers in this study postulated that each of the three components eye opening, verbal and motor, as well as a simplified motor scale were just as good as the full 15-point Glasgow Coma Scale in predicting the severity of traumatic brain injury. In this study, the authors defined severe brain injury as those patients who required ED intubation, neurosurgical intervention or documented brain injury (including skull fracture) or patients who died.
The authors reviewed the charts of 7,299 trauma patients presented to a level one trauma center during a 12-year period. In their research, they discovered that the GCS eye scale demonstrated the weakest predictive value. Individually, the verbal and motor components were as predictive of severe brain injury as the total GCS score.
To prove their findings, the authors developed a Simplified Motor Scale and a Simplified Verbal Scale, and then they measured each scale’s predictive value. The authors found that the Simplified Verbal Scale was good, but it was not as good as the Simplified Motor Scale in predicting all four outcome variables.
Here is their simplification of the GCS Verbal and Motor Scales:
Alternative ScoreScoreGCS EquivalentSimplified Verbal ScaleOriented2Verbal = 5Confused1Verbal = 4Inappropriate or less responsive0Verbal = 3Simplified Motor ScaleObeys Commands2Motor = 6Localizes pain1Motor = 5Withdrawal to pain or less response0Motor = 4The Street
For years we have been asked to calculate the Glasgow Coma Scale in the field. Nobody can remember it. We all have to pull out the card and look up the value for each finding. In some instances, I’ve reviewed charts where the medic gave a completely unresponsive and comatose patient a score of ZERO, thinking that this would be the lowest score possible. Of course, we all know that the lowest score for the GCS is 3, right?
In other instances, using this scoring mechanism, which was developed more than 30 years ago, has resulted in different scores when applied by two physicians performing an exam five minutes apart on the same patient. But because the trauma registries require a revised trauma score that requires a GCS be calculated and put into their databanks, we have been hammered over the head time and again to use it.
In terms of prehospital assessment of a head injured patient, what are we really concerned about? We want to know if the patient has injuries that are more than likely to require neurosurgical intervention. If they do, then we need to take the patient to the appropriate hospital, or at least get things rolling to ensure the patient gets transferred to a trauma center quickly. We don’t need to be spending time in the field crunching numbers, especially if a simple set of criteria can give us the information we need, as this study demonstrated.
Of course, more studies are needed to confirm the validity of these simplified scales, but I believe these scales are the future. They are quick, simple and reliable assessments that give us all we need to know to determine the potential for significant brain injury.
