Bispectral index predicts deaths within 2 weeks in coma patients, a better predictor than serum neuron-specific enolase or S100 protein

• DOI: 10.1007/s00540-013-1654-0
• Publication Date: 2013-08-10T08:24:52Z
• Authors: Wenli Miao; Yuanxin Zhang; Hailing Li
• Keywords: Enolase; Bispectral index; Youden's J statistic; Cut-off; Coma (optics)

We assessed the ability of bispectral index (BIS) to predict clinical outcome (dead or alive within 2 weeks).In total, 90 coma patients with severe brain injuries underwent BIS monitoring, and serum neuron-specific enolase (NSE) and S100 protein levels were assayed within the first 3 days of admission. Receiver operator characteristic (ROC) curve analysis was used to assess the performance of BIS values for predicting death within 2 weeks. A cutoff value was calculated using the Youden index.A significant negative correlation was found between BIS value and serum NSE and S100 levels. The area under the curve for BIS value was 0.841 (p < 0.001, 95 % CI = 0.751-0.931), and higher than for NSE (0.713) (p = 0.002, 95 % CI = 0.582-0.844) or S100 (0.790) (p < 0.001, 95 % CI = 0.680-0.899). The optimal cutoff of BIS was 32.5. Serum NSE and S100 protein levels and the mortality rate were significantly lower in patients with a BIS value >32.5 than in patients with a BIS value ≤32.5.Bispectral index values may reflect degree of brain injury, and BIS is an objective and noninvasive monitoring method for helping clinicians to predict death in patients with a BIS value ≤32.5.