Depth of Hypnosis and Postoperative Nausea and Vomiting During Xenon Anaesthesia

The purpose of this study is ad 1) to measure the depth of hypnosis as assessed by BIS and cAAI during an average general anesthesia with xenon or sevoflurane and to establish a reliable monitoring system for measuring and documenting the actual depth of hypnosis for the volatile anesthetics investigated. Ad 2) the question is to be answered whether 4 mg dexamethasone i.v. is an effective prophylactic treatment against postoperative nausea and vomiting in case of xenon or sevoflurane anesthesia. Ad 3) it serves to gain evidence about the (non-)effectiveness and kinetics of ondansetron as antiemetic remedy after xenon or sevoflurane anesthesia.