Sino-nasal Inhalation of Sodium Chloride 6,0% in Patients With Cystic Fibrosis and Chronic Rhinosinusitis

Inclusion Criteria: * Subject has a confirmed diagnosis of cystic fibrosis based on: 2 positive sweat chloride tests and/or genetic characterization * Subject is 8 years of age or older * informed consent of the patient or legal representative * Women of childbearing potential are only included into the study, if they are using an effective method of birth control during the protocol (failure rate \<1% e.g. implants, combined oral contraceptives, injectables, some intrauterine devices, sexual abstinence or vasectomised partner) Exclusion Criteria: * Subject has no chronic rhinosinusitis (European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS-criteria) * Subject has a critical condition defined as: forced expiratory volume at one second \< 30% and / or arterial oxygen saturation \< 93% without O2-substitution; need of O2-substitution * Subject had an ENT surgery within 6 months prior to study * Subject participates in another clinical trial within 30 days prior to study entry