1. Department of Anesthesiology and Intensive Care Medicine, Universitätsklinikum Bonn, Bonn, Germany
2. Department of Anesthesiology and Intensive Care Medicine, Heilig Geist Krankenhaus Köln, Cologne, Germany
3. Department of Anesthesiology and Perioperative Medicine, Orthopädische Klinik Markgröningen GmbH, Markgroningen, Germany