Chapter 51 Continuous ICU EEG monitoring

Abstract

Publisher Summary Continuous intensive care unit (ICU) electroencephalography (EEG) monitoring is meant to observe and detect the nervous system impairment in the ICU. Such monitoring allows clinicians the opportunity to intervene promptly to reverse an adverse process. This chapter discusses the usefulness of EEG in continuous ICU monitoring is based on a number of facts about EEG. The number of channels monitored continuously has increased substantially. Mass storage media now allows the saving of all EEG tracings. Continuous ICU EEG can be combined with other monitoring modalities, such as evoked potentials, intracranial pressure, electrocardiogram (EKG), or oximetry. Surgical endarterectomy monitoring teaches us about the EEG changes and brain tolerance during ischemia. Long-term video-EEG monitoring for epilepsy provide a technical basis for monitoring over many days and the use of spike and seizure detectors. Multi-modality integration is similar to polysomnography displays of sleep architecture. Routine EEG provides the understanding of transients seen in the ICU, such as triphasic waves. In the UCLA model for these services, quantitative trending of relative alpha, total power and alpha/delta ratio displays and identifies gradual or abrupt EEG changes. Seizures show up as surges in total power. Automated seizure detectors could also be used. Changes in the symmetry and frequency content can be seen in these power and ratio trends. Continuous EEG monitoring help manage therapy in head injury, cerebral ischemia infarctions, and hemorrhage-related vasospasm. In other patients in coma, it can supplement routine clinical monitoring and help elucidate diagnoses in some cases. Deteriorating variability warns of complications after subarachnoid hemorrhage. Deterioration of variability can occur a day prior to clinically apparent deterioration in patients at risk for vasospasm. Therefore, monitoring can warn against premature ICU discharge.