Progressive changes in the electroencephalogram produced by ketamine Progressive changes in the electroencephalogram produced by ketamine. Stages 1 to 3 are achieved with racemic ketamine and its S(+) isomer. With R(–) ketamine, stage 2 was the maximal electroencephalographic depression produced. [Redrawn from Kilpatrick GJ. New drugs for sedation and hypnosis. Presented at the 2005 EuroSIVA Annual Scientific Meeting, Vienna, Austria, May 27-28, 2005.] Source: Anesthesia Drugs and Drug Delivery Systems, Anesthesiology, 3e Citation: Longnecker DE, Mackey SC, Newman MF, Sandberg WS, Zapol WM. Anesthesiology, 3e; 2017 Available at: http://accessanesthesiology.mhmedical.com/DownloadImage.aspx?image=/data/books/2152/longnecker3_ch37_f005.png&sec=164223543&BookID=2152&ChapterSecID=164142703&imagename= Accessed: October 27, 2017 Copyright © 2017 McGraw-Hill Education. All rights reserved