Clinical Pearl 72: GCSm: A New Standard Of Care In Assessing The Trauma Patient

The standard GCS score consists of visual, verbal and motor subscores. A randomized controlled trial published in Annals of Emergency Medicine in 2015 assessed the accuracy of EMS providers' GCS scoring as well as the improvement in the GCS score assessment with the use of a scoring aid. 178 completed the study. Overall, 41% gave a GCS score that matched the expert consensus score. GCS score was correct in 25% cases without the scoring aid. GCS was correct in 57% cases with the scoring aid. Differences in accuracy were most pronounced in scenarios with a correct GCS score of 12 or below. In summary, 60% of the EMS participants provided inaccurate GCS score estimates and the use of a GCS scoring aid improved accuracy of their score assessments.  So, instead of using a scoring aid why not just implement a simplified version of the GCS scoring system to minimize inaccuracy?

Another study published in Annals of Emergency Medicine in 2007 aimed to validate the Simplified Motor Score in a large heterogeneous trauma population. This was a secondary analysis of a prospectively maintained trauma registry with consecutive trauma patients who presented to a Level I trauma center from 1995 through 2004. Test performance of the GCS and the Simplified Motor Score relative to 4 clinically relevant traumatic brain injury outcomes (emergency intubation, clinically significant brain injury, neurosurgical intervention, and mortality) was evaluated with areas under the receiver operating characteristic curves (AUCs). The AUCs for the GCS and its components ranged from 0.76 to 0.92 across the 4 outcome measures. The AUCs for the Simplified Motor Score ranged from 0.71 to 0.89, and the relative differences from the GCS AUCs ranged from 3% to 7%, with a median difference of 5%. In this external validation study, the 3-point Simplified Motor Score (SMS) demonstrated similar test performance when compared with the 15-point GCS score and its components for the prediction of 4 clinically important traumatic brain injury outcomes. A second study of nearly 20,000 ICU trauma patients from 2011 found that the SMS acted equally to the GCS in predicting select trauma outcomes, offering it as an easier tool for pre-hospital providers to utilize in their trauma assessment.

In 2014, a study published in Journal of trauma and Acute Care Surgery, evaluated performance of the National Trauma Triage Protocol if GCm is substituted for the classic GCS score. GCSm score ≤ 5 increases specificity at the expense of sensitivity compared with GCS score ≤ 13.

In 2016, Doug Kupas and colleagues, in an evaluation of trauma outcomes from the Pennsylvania trauma data base, found that patients with a GCS- motor component less than 6 (“patient does not follow commands”) was equally effective in predicting select trauma outcomes (intubation, surgery, ICU admission, craniotomy, etc) as GCS, and again would serve as simple binary tool for EMS providers to utilize in their trauma assessment.

GCSm is superior to Total GCS.  Having a patient follow a motor command provides the easiest method to determine GCSm in a rapid accurate way.

References:

Brown JB, Forsythe RM, Stassen NA, Peitzman AB, Billiar TR, Sperry JL, Gestring ML. Evidence-based improvement of the National Trauma Triage Protocol: The Glasgow Coma Scale versus Glasgow Coma Scale Motor Subscale. J Trauma Acute Care Surg. 2014 Jul;77(1):95-102

Jaukoos JS, Gill MR, Rabon RE, Gravitz CS, Green SM. Validation of the Simplified Motor Score for the prediction of brain injury outcomes after trauma. Ann Emerg Meg. 2007 Jul;50(1):18-24.

Thompson DO, Hurtado TR, Liao MM, Byyny RL, Gravitz C, Haukoos JS. Validation of the simplified motor score in the out-of-hosptial setting for the preduction of outcomes after traumatic brain injury. Anne Amerg Med. 2011 Nov;58(5):417-25.

Feldman A, Hart KW, Lindsell CJ, McMullan JT. Randomized controlled trial of a scoring aid to improve Glasgow Coma Scale Scoring by emergency medical services proviers. Ann Emerg Med. 2015 Mar;65(3):325-329.e.2

Kuppas DF, Melnychuk EM, Young AJ. Glasgow Coma Scale Motor Component (“Patient Does Not Follow Commands”) Performs Similarly to Total Glasgow Coma Scale in Predicting Serve Injury In Trauma Patients. Ann Emerg Med. 2016 Dec.68(6):744-750.