Use of bispectral electroencephalogram monitoring to assess neurologic status in unsedated, critically ill patients.

Objective: To test whether spectral indices derived from the electroencephalogram (EEG), and especially the bispectral index (BIS), can be used as measures of neurologic status in unsedated, critically ill patients.

Design: Prospective, observational study.

Setting: Medical intensive care unit (ICU) of a university-affiliated teaching hospital.