Comparison of multiple breath washout and particles in exhaled air for assessment of small airway function in children with cystic fibrosis

Pediatric volunteers with cystic fibrosis age 8-18 years
Healthy pediatric volunteers age between 8 and 18 years

A potential subject who meets any of the following criteria will be excluded from participation in this study:
- (History of)(passive) smoking, exclusion will take place when a subject has smoked in the last year, or has a smoking history of > 0.5 pack year (including e-cigarette, water pipe and smoking of cannabis). According to the validated definition of the Dutch PYAMA study passive smoking is defined as exposure in the household or in another indoor setting more than 2 times a week.
- (History of) cardiac disease
- History of premature birth before 36 weeks of gestational age
- Pregnant women, who are visually pregnant as judged by the investigator. The tests are harmless for the pregnant woman and the unborn child. However, due to pressure to the diaphragm the lung function can change.
- Fever, common cold or respiratory tract infection < 3 weeks before visit, as judged by the investigator;Control specific exclusion criteria:
- Abnormal spirometry defined as < 80% FEV1 or < -1.64 SD 30
- (History of) chronic or severe lung disease