1 Department of Anesthesiology and Intensive Care, School of Medicine and Health, Technical University of Munich, Munich, Germany. Electronic address: s.himmelseher@gmx.de.
2 Department of Anesthesiology, Academic SRH Hospital Sigmaringen, Sigmaringen, Germany.
3 Department of Anesthesiology and Intensive Care Medicine, School of Medicine, University of Ulm, Ulm, Germany.
4 Department of Anesthesiology, West Virginia University School of Medicine, Morgantown, WV.
5 Ruhr-University Bochum, Bad Oeynhausen, Germany.