EEG monitoring for anesthetic depth assessment

The authors discuss classical signs and assessment of anesthetic depth as well as EEG applications. Assessment of anesthetic depth still rests on clinically relevant signs in use for more than a century. These signs, variable among different anesthetics and in the presence of other drugs, correlate imperfectly with anesthetic depth. Despite these limitations, there often are no other means to assess anesthetic depth. The vagaries of correlation between clinical signs and anesthetic depth, as well as the lack of further developments in monitoring anesthetic depth, stem partially from incomplete understanding of the brain activities most closely linked to perception, awareness and consciousness.<>