Full Outline of Unresponsiveness compared with Glasgow coma scale assessment and outcome prediction in coma

Introduction

The most widely adopted scale to assess consciousness in severely brain-damaged patients is the Glasgow coma scale (GCS) [1]. Its major shortcomings are the failure to assess the verbal component in intubated patients, the inability to test brainstem reflexes and breathing patterns. In 2005, Wijdicks and colleagues proposed a new coma scale, the Full Outline of Unresponsiveness (FOUR) scale [2], which consists of four components (eye, motor, brainstem, and respiration), each component having a maximal score of 4. Our objective was to validate the French version of the new FOUR coma scale in a general ICU and to assess its predictive value as compared with the GCS.

Methods

We performed FOUR and GCS evaluations in randomized order in 176 acutely brain-injured patients (days from insult to randomization <1 month). We assessed the association between GCS and FOUR scores using the Spearman correlation coefficient. A logistic regression analysis adjusted for age and etiology of coma was performed to assess the link between the studied scores and the outcome based on the Glasgow outcome scales 3 months after injury (n = 63).

Results

The GCS and FOUR showed a significant correlation (r = 0.807). The GCS verbal component was scored 1 in 146 patients; among these, 131 were intubated. The FOUR total scores (corrected for age) showed superior outcome prediction at 3 months (OR = 0.83; 95% CI = 0.70 to 0.98, P = 0.03) as compared with GCS total scores (OR = 0.85; 95% CI = 0.70 to 1.03, P = 0.09).

Conclusion

The FOUR scale does not need a verbal response, thus allowing complete testing in intubated patients (in our sample 90% of patients showing a GCS V1 score were intubated). Most importantly, the FOUR scale demonstrated a better discrimination between the good (recovery of independent living) and poor neurological status at 3 months as compared with the GCS.