1 Department of Anesthesiology, Intensive Care Medicine and Pain Therapy, University Hospital Muenster, Muenster, Germany alexander.schnabel@ukmuenster.de.
2 Department of Anaesthesiology, Intensive Care, Emergency and Pain Medicine, University Hospital Wuerzburg, Wuerzburg, Germany.
3 Department of Anesthesiology, Intensive Care Medicine, Palliative Care Medicine and Pain Management, Professional Association University Hospital Bochum, Ruhr-Bochum University, Bochum, Nordrhein-Westfalen, Germany.
4 Department of Anesthesiology, Intensive Care Medicine and Pain Therapy, University Hospital Muenster, Muenster, Germany.