1. Institute for Medical Informatics Statistics and Documentation; Medical University of Graz; Graz Austria
2. Division of Anesthesiology for Cardiovascular Surgery and Intensive Care Medicine; Medical University of Graz; Graz Austria
3. Department of Anesthesiology and Intensive Care; Jena University Hospital; Germany
4. Department of Orthopedics and Orthopedic Surgery; Medical University of Graz; Austria