1. Pediatric Clinic, Department of Medicine and Surgery, University of Parma, Via Gramsci 14, 43124 Parma, Italy
2. Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 01451, USA
3. Cystic Fibrosis Unit, Pediatric Clinic, Az. Ospedaliera-Universitaria di Parma, Via Gramsci 14, 43124 Parma, Italy