Materials and methods
The study was approved by the institutional review board of Friedrich Schiller University Hospital, Jena, Germany. Informed consent was waived due to the retrospective,
anonymous nature of the analysis. We retrospectively included all adult (>18 years old) patients admitted to our 50-bed surgical ICU between 1 March 2004 and 30 July
2006. For patients admitted more than once to the ICU only the first admission was considered.
according to a trigger of 9.5 g/dl.