Inhaled Sevoflurane Compared to Intravenous Sedation Post Coronary Artery Bypass Grafting

Inhaled sevoflurane during coronary artery bypass grafting (CABG) reduces postoperative Troponin levels and may be associated with improved outcome. A dose-response effect has been demonstrated by de Hert et al, with greatest reductions of Troponin when Sevoflurane was used during the entire operation, as compared to Sevoflurane during parts of the operation. Sevoflurane, as other inhaled anesthetic agents, is sedative in low doses. Postoperative sedation after CABG is currently achieved with intravenous propofol. A new simplified method of administration of isoflurane or sevoflurane has been developed and tested by members of the research group. The Anesthetic Conserving Device is a modified heat-moisture exchanger (HME) that permits direct infusion of sevoflurane to the airway, where it is vaporized in an evaporator rod in the device. The primary aim (and primary hypothesis)of the current trial is to examine if postoperative sedation with sevoflurane after CABG is associated with improved cardiac outcome, measured as reduced levels of Troponin, BNP and reduced incidence of cardiac events, such as atrial fibrillation, need for inotropic drugs and myocardial infarction, compared with conventional propofol sedation. Other end-points of the trial are potential renal (protective) effects measured with cystatin C levels, need for dialysis but also measurements of inorganic fluorides in serum, as well as environmental aspects of sevoflurane sedation in a Cardiothoracic Intensive Care Unit. Furthermore, potential differences in ICU memories and well-being during stay in the intensive Care Unit will be investigated via patient questionnaires. Besides routine blood sampling, plasma will be saved for later analysis of inflammatory mediators (biobank).