1 Department of Anesthesia and Intensive Care Medicine, Oslo University Hospital, Oslo, Norway; Department of Anesthesiology, Bern University Hospital Inselspital, University of Bern, Bern, Switzerland. Electronic address: axsa@online.no.
2 Department for Anesthesia, Intensive Care Medicine and Pain Therapy, BG Unfallklinik Frankfurt am Main gGmbH, Frankfurt, Germany; Department of Anesthesiology and Intensive Care, Philipps University Hospital, Philipps University Marburg, Marburg, Germany.