1. Department of Anaesthesia and Intensive Care Medicine; University of Duisburg-Essen and Essen University Hospital; Essen Germany
2. Department of Anaesthesia, Intensive Care, Pain and Palliative Medicine; Marien Hospital Herne; Ruhr-University Bochum; Bochum Germany
3. Institute of Pharmacogenetics; University of Duisburg-Essen and Essen University Hospital; Essen Germany