Detection of Unsuspected Small Airways Obstruction in Cystic Fibrosis
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Goal is to physiologically detect unsuspected small airways obstruction in children and adults with treated heterozygous and homozygous cystic fibrosis. Unsuspected refers to normal routine pre bronchodilator spirometry including normal FEV1(L), FVC (L). and FEV1/FVC%. This is a retrospective study.
Condition or disease
Cystic Fibrosis in Children
Diagnostic Test: spirometry
The current study is based on current investigators previously published patho-physiologic and lung CT studies in small airways intrinsic obstruction, emphysema, and asthma. Current investigators have demonstrated that despite the presence of normal routine spirometry including normal FEV1(L), FVC (L), and FEV1/FVC% that unsuspected small airways obstruction, and emphysema can be detected. This has been achieved by presence of isolated abnormal expiratory airflow limitation at low lung volumes on the maximal expiratory flow volume curves. This includes abnormal expiratory airflow at 75% and 80% expired lung volume. Current investigators believe investigators will be able to detect unsuspected small airways intrinsic obstruction, and peripheral airway bronchiectasis proven by lung CT, in patients with cystic fibrosis despite presence of pre bronchodilator normal routine spirometry.
Detection of Unsuspected Small Airway Obstruction in Cystic Fibrosis [ Time Frame: 2 years ]
Retrospective analysis of pre bronchodilator spirometry, and lung CT study to detect abnormal FEF75% in the presence of normal spirometry and FEF25-75. Detect isolated abnormal pre bronchodilator spirometry at 75%FVC
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Layout table for eligibility information
Ages Eligible for Study:
6 Years to 40 Years (Child, Adult)
Sexes Eligible for Study:
Accepts Healthy Volunteers:
Review pulmonary function and radiologic studies in retrospective records of heterozygote or homozygote patients with cystic fibrosis
Heterozygote or homozygote patients with cystic fibrosis with normal routine pre bronchodilator spirometry including normal FEV1(L), FVC(L) and FEV1/FVC%.
Exclusion Criteria:Heterozygote or homozygote patients with cystic fibrosis with ABNORMAL routine pre bronchodilator spirometry