Methods Patients All the procedures described in this study were approved by the local Ethics Committee (No. 375/2007), and informed consent was obtained from all patients or by proxy. The study was conducted prospectively between 2008 and 2011 in nine ICUs (three medical, six surgical; all together 72 beds) located in the General Hospital of Vienna/Medical University of Vienna according to the Helsinki Declaration of 1975, as revised in 1983.