EEG monitoring in anesthesiology and intensive care

Knowledge of the actual state of cerebral function and of the changes induced by psychotropic drugs is important not only to neurologically oriented specialties but also to other branches of medicine concerned with altering cerebral function. This applies especially to anesthesiology which involves numerous procedures leading to a temporary loss of cognitive brain function. Recently, the application of EEG combined with spectral analysis performed during anesthesia and intensive-care treatment has attracted attention: we investigated the changes in EEG during standardized anesthesiological and therapeutical procedures pre-, intra- and postoperatively, or during intensive-care treatment in 1,500 patients undergoing general surgery from 1977 to 1982. Two-track EEG leads accompanied by spectral analysis were used on line. The evaluation of routinely applied EEG monitoring justifies the following statements: EEG monitoring can be adapted technically and organized to comply with the working conditions and daily activities of an anesthesiological department. Spectral analytic representations allow the assessment of the EEG by the anesthesiologist. The various methods of general anesthesia produce specific EEG changes which can be obliterated by the cumulative effect of drugs. The actual depth of anesthesia is visible in the EEG. During a defined constant anesthetic depth, potentially hazardous cerebral dysfunctions can be detected early and treated accordingly. EEG monitoring can be useful in solving urgent medical problems of intensive-care therapy.