The Prevalence of Small Airways Dysfunction In COPD Patients and The Impact on COPD Control

This is a prospective cross-sectional interventional design. 100 COPD patients who applied to Mersin University Faculty of Medicine Hospital Chest Diseases Clinic between 01.10.2019-01.04.2020 will be taken. 35 healthy participants with smoking history and 35 healthy participants without smoking history who were admitted to our clinic within the same date range will be taken as control group. Impulse oscillometric pulmonary function tests will be performed to all participants. Thorax computed tomography will be performed to evaluate small airway dysfunction. To evaluate the degree of disease inflammation and phenotype in COPD patients, nitric oxide measurements will be made in the breath air with fractional exhaled nitric oxide (FENO) device. The blood eosinophil level will be studied to determine the COPD phenotype. To assess symptom control in patients with COPD, mMRC(Modified Medical Research Council) dyspnea scale will be administered. The COPD assessment test (CAT) will be applied to measure the quality of life. All patients will be followed for 1 year to record the number of exacerbations requiring emergency and hospital admissions for COPD. The effect of small airway dysfunction on the disease severity and control degree, disease phenotypes and quality of life, and the effect on the risk of exacerbation will be analyzed.