[EEG parameters in the monitoring of ventilated intensive care patients under various sedation methods]

Visual evaluation of the EEG and spectral analysis of the background activity are useful in monitoring changes of cerebral function caused by sedatives, hypoxia and changes in state of health. Continuous slow changes of the EEG are indicative of critical situations of cerebral blood flow or metabolism. Monitoring cerebral function of 40 sedated and ventilated patients on an intensive care unit, we found typical EEG changes dependent on different regimes of sedation, amount of sedatives and patient condition. In patients sedated with etomidate, there was a good correlation between the relative power of the delta and beta-band and patient condition. Sedation with thiopental caused flattening and slowing of the EEG, as well as a decrease of total power, if the doses were increased. The EEG was an aid to predicting the outcome of intensive care and to demonstrate the degree of cerebral damage. In patients with septicaemia, cerebral function was more depressed than in patients with cardiac failure. Spectral analysis and computed parameters proved to be valuable in monitoring cerebral changes caused by sedation and state of health in ventilated patients.