1 Department of Anaesthesiology and Critical Care Medicine, Medical University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria. Electronic address: bernd.wallner@i-med.ac.at.
2 Department of Anaesthesiology and Critical Care Medicine, Medical University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria. Electronic address: gabriel.Putzer@i-med.ac.at.
3 Department of Anaesthesiology and Critical Care Medicine, Medical University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria. Electronic address: p.mair@tirol-kliniken.at.