Abstract

Background: Monitoring the level of consciousness in patients with traumatic brain injury (TBI) has a key role in the patients’ care, treatment, and prognosis. Currently the Glasgow Coma Scale (GCS) is the most commonly used tool for measuring the level of consciousness in these patients. The Bispectral index (BIS) is a novel tool for measuring consciousness in patients with brain injury. We aimed to assess the correlation between GCS and BIS scores in patients with mild and moderate TBI.
Methods: In this descriptive correlational study, 47 patients with mild (GCS=13-15) and moderate (GCS=9-12) TBI were enrolled using the simple randomization method. We included 18-60 year-old patients admitted to Shahid Mohammadi Hospital, Hormozgan, Southern Iran, who were examined by a neurologist during the study period. We measured their level of consciousness using the GCS for 6 hours with one-hour intervals. Simultaneous with GCS measurement, the patients’ BIS was also monitored and recorded every 15 minutes. Pearson’s correlation coefficient and the linear regression model were used. We also determined the specificity and sensitivity of the BIS through ROC curve analysis.
Results: Of the 47 studied patients, 40 (85.1%) were men. The mean±SD age of the patients was 28.8±10.2 years (range:18-59 years). We found a significant relationship between BIS and GCS scores in our patients (r=0.372, P=0.014). Moreover, BIS could be used to differentiate patients with mild and moderate TBI using the ROC curve (P=0.004).
Conclusion: The simultaneous and consistent alterations between the two scores could indicate these measurements’ relations to the severity of trauma and depth of coma. However, the changeable nature of BIS scores for each GCS score could reduce its application for predicting the depth of coma and severity of trauma. We suggest that the BIS device be used as an assisting aid to consistently monitor the level of consciousness in patients with mild and moderate TBI.