Both ischemia-reperfusion new product injury and the inflammatory response syndrome negatively affect patient outcome.For several years, inhalational agents have been successfully used for sedation of ventilator-dependent patients in the intensive care unit (ICU) and have become a valuable alternative to commonly used intravenous drugs [6]. Studies have shown that the method of sedation with volatile anesthetics [7] results in shorter time to extubation and faster mental recovery compared with intravenously administered sedatives [8,9]. Recently, a new tool for postoperative volatile sedation of ventilated patients in the ICU has been established: the Anaesthetic Conserving Device (AnaConDa; Sedana Medical, Uppsala, Sweden).The protective effects of volatile anesthetics on organ preservation have been studied extensively.

Several clinical trials have demonstrated that volatile anesthetics decrease cardiac injury after procedures involving the use of ECC [10-13]. Most often, volatile anesthetics have been used in a preconditioning manner or during the entire surgical procedure. This randomized controlled trial, in contrast, examined the effect of sevoflurane in a clinical setting of late postconditioning in patients undergoing cardiac surgery with ECC. Sevoflurane was therefore administered only postoperatively by using the AnaConDa system [14,15]. We hypothesized that late and short-time application of sevoflurane in low anesthetic gas concentration would attenuate myocardial ischemia-reperfusion injury after cardiopulmonary bypass procedures and possibly have a positive impact on pulmonary function.

Materials and methodsStudy designThis is a prospective randomized parallel group trial comparing postoperative propofol with sevoflurane sedation in the ICU after on-pump cardiac surgery. All patients between 18 and 90 years of age, scheduled for elective cardiac surgery requiring the use of ECC at the University Hospital Zurich, Switzerland, were eligible. Exclusion criteria were poor cardiac baseline function, defined as an ejection fraction of < 30%, significant coronary impairment (CCS �� 3 or myocardial infarction within 7 days before the surgery date), emergency procedures, previous cardiac surgery, chronic pulmonary disease (FEV1 < 80% or FEV1/FVC < 70% of predicted value), renal dysfunction (creatinine clearance, < 60 ml/min), insulin-dependent diabetes mellitus, pregnancy, and current steroid treatment.

Randomization was computer generated with prestratification for the following surgery groups: (a) aortic valve surgery, (b) mitral valve surgery, and (c) combined procedures with coronary artery bypass grafting (CABG) or GSK-3 replacement of the ascending aorta. The envelope was opened by an investigator at the end of the case. Anesthesiologists and surgeons were blinded to the intervention.