1. Department of Anaesthesia; University Children's Hospital; Zurich; Switzerland
2. Department of Paediatric Otolaryngology; Great Ormond Street Hospital for Children; London; UK
3. Department of Otolaryngology; University Children's Hospital; Zurich; Switzerland
4. Department of Otolaryngology; Sophia Children's Hospital, Erasmus University Medical Centre; Rotterdam; Netherlands
5. Department of Paediatric Pulmonology and Intensive Care Medicine; UKBB; Basel; Switzerland
6. Department of Paediatric Pulmonology and Intensive Care Medicine; Dr. von Hauner’ Children's Hospital; University of Munich; Germany