The maximum value of bispectral index predicts outcome in hypoxic-ischemic encephalopathy after resuscitation, better than minimum or mean value.

OBJECTIVE: Although bispectral index (BIS) has been widely used for predicting neurological outcomes in clinical practice, its optimal value concerning maximum (BISmax ), minimum (BISmin ) and mean (BISmean ) on accurately predicting the prognosis of patients with hypoxic-ischemic encephalopathy (HIE) after resuscitation has not been clearly determined.

METHODS: For a total number of 45 cases, the duration of each BIS measurement was 12 h, with the data collected at a 30 min interval. Outcome was recorded as survival and non-survival count 60 days after the resuscitation. Receiver operator characteristic curve was used to assess the BISmax, BISmin and BISmean for predicting clinical outcome.

RESULTS: By the end of observation, 20 cases (44.4%) survived with a significantly higher BISmax . The area under the curve for BISmax of predicting survival was the highest compared to BISmin and BISmean . The optimal cut-off value of BISmax was 71.5 with 100% sensitivity and 60% specificity. Ten patients presented BIS value down to zero at any time point did not survive the observation.

CONCLUSION: The BISmax is a better outcome predictor than BISmin or BISmean for patients with HIE after resuscitation. Lower BISmax represents higher risk of mortality. Additionally, BIS value decreases to zero represents a poor outcome.