 Blood samples will be drawn before incision baseline, during cardiopulmonary bypass and after release of the aortic cross clamp. Subsequently, blood samples will be drawn on arrival at the intensive care unit and three and six hours after arrival. On post-operative day 1 and 2 blood samples will be drawn on the ICU or the medium care. All samples will be stored according the hospital blood banking protocol and analyzed at once at the end of the study. Left over material will be discarded after all necessary analysis has been conducted. 