Prediction of neurological outcome using bispectral index in patients with severe acute brain injury

Authors: WANG XIFENG, ZHANG LIANSHUANG, WU DAWEI

Abstract: To predict consciousness recovery and outcome of patients with severe acute brain injury using the bispectral index (BIS). Materials and methods: A prospective study of 189 brain-injured patients was made when they were without sedatives for at least 24 h. BIS, 95% spectral edge frequency (SEF), burst suppression ratio (SR), total power (TP), spontaneous electromyographic activity (EMG), and signal quality index (SQI) were recorded continuously for 30 min. Neurologic conditions were measured with the Glasgow Coma Score (GCSBIS) when recording BIS. Patients were followed for 30 days after injury to assess consciousness recovery and outcome. Results: There were statistically significant differences in BIS measurements between patients that recovered consciousness or survived and those who did not. The best correlation coefficients for patients' outcome were 0.738 for GCSBIS, 0.639 for SR, and 0.591 for BIS. As to the patients' consciousness recovery, the best coefficients were 0.656 for GCSBIS, 0.526 for BIS, and 0.511 for SR. According to the area under the receiver operating characteristic curve, the best values to predict consciousness recovery and survival were GCSBIS and BIS, and for unconsciousness and death, the best parameters were SR, APACHE II score, and SEF. Conclusion: BIS measurement is useful to predict consciousness recovery and outcome in severe acute brain injury.

Keywords: Bispectral index, brain injury, outcome, recovery

Full Text: PDF