[1] Univ Roma La Sapienza, Cyst Fibrosis Ctr, Dept Pediat & Pediat Neurol, I-00185 Rome, Italy
[2] Univ Roma La Sapienza, Dept Thorac Surg, I-00185 Rome, Italy
[3] Univ Roma La Sapienza, Dept Anaesthesiol & Intens Care, I-00185 Rome, Italy
[4] Univ Trieste, IRCCS Burlo Garofolo, Inst Maternal & Child Hlth, Cyst Fibrosis Ctr,Pediat Dept, Trieste, Italy
[5] Royal Brompton Hosp, Dept Cyst Fibrosis, London SW3 6LY, England
[6] Univ London Imperial Coll Sci Technol & Med, London, England