1 Department of Anesthesiology and Intensive Care Medicine, University of Cologne, Kerpener Str. 62, 50937, Cologne, Germany. Electronic address: hendrik.drinhaus@uk-koeln.de.
2 Department of General, Visceral, and Cancer Surgery, University of Cologne, Cologne, Germany.
3 Department of Anesthesiology and Intensive Care Medicine, University of Cologne, Cologne, Germany.