<qa>  What is the potential benefit of inhalative sedation on the ICU?The evaluation of the presented study will work on the practicability of inhalative sedation on the ICU, potential benefits and limitations of the ACD system in a postoperative sedated patient population in comparison to a standard intravenous sedation regimen with propofol, and focus on renal and hepatic function, cardioprotection and pharmacoeconomics 