1. Department of Plastic, Aesthetic, Hand and Reconstructive Surgery, University Hospital, University of Regensburg, Regensburg, Germany
2. Department of Otorhinolaryngology, University of Munich, Munich, Germany
3. Department of Anesthesiology and Intensive Care Medicine, University Hospital, University of Regensburg, Regensburg, Germany
4. Department of Anesthesiology and Intensive Care Medicine, St. Josef Hospital Regensburg, Regensburg, Germany