Bodyplethysmography and helium dilution method in patients with COPD: correlation between functional and respiratory clinical parameters

Chronic obstructive pulmonary disease (COPD) currently occupies sixth place in the list of morbidity causes in the world adult population and is catching third in 2020; smoking is the most important cause. COPD mortality reaches 200-300%ooo for the age group 45-64 years, 6% of deaths in men and 4% of deaths in women. Mortality from the disease is increasing at 3rd place in 2020, the disease having higher mortality statistics as expected. Positive diagnosis of COPD is given by objectifying functional bronchial obstruction by performing spirometry in a patient who is smoker or exposed to pollutants. Investigation of the respiratory function in patients with COPD is essential. Spirometry is considered to be the most reproducible, inexpensive, and the routine test for measuring airflow limitation.