[Sleep and sedation: clinical and electrophysiological parallels]

Clinical and electrophysiological studies were performed in 10 volunteers and 45 patients with Classes I and II, as stated by the American Society of Anesthesiologists, to evaluate consciousness during sedation. Prior studies on volunteers showed that there was a clear correlation between N-REM sleep and SEF in 90% of cases. Based on these findings, the authors propose a modified suppressed consciousness scale whose rating was adjusted to the levels of N-REM sleep. Irrespective of the type and technique of sedation (infusion of thiopental and propofol; PCS, midazolam), changes in the levels of drug-depressed consciousness were found to be the same.