1. Division of Respiratory and Critical Care Medicine; University Children's Hospital Basel; Switzerland
2. Department of Pediatrics, Dr. von Hauner Children's Hospital; Ludwig-Maximilians-University; Munich Germany
3. Department of Anesthesia; University Children's Hospital Zurich; Switzerland
4. Division of Pediatric Pulmonology and Allergology; Department of Pediatrics and Adolescent Medicine; Medical University of Graz; Austria