[1] Univ Zurich, Zurich, Switzerland
[2] Kantonsspital Luzern, Klin Anasthesiol, Luzern, Switzerland
[3] Univ Klinikum Schleswig Holstein, Stabsstelle Organisat, Projekt & Qualitatsmanagement, Lubeck, Germany
[4] Univ Schleswig Holstein, Klin Anasthesiol & Operat Intensivmed, Kiel, Germany