[Diagnosis and examination for COPD. Pulmonary function tests].

Pulmonary function tests are essential for the diagnosis and management of COPD. It is important to understand the inspection method of tests and the interpretation of test results. The presence of a post-bronchodilator FEV1/FVC<0.70 confirms the presence of persistent airflow limitation and the diagnosis of COPD. On the other hand, the classification of severity of airflow limitation in COPD is based on %FEV1. In COPD patients, as airflow limitation worsens gas trapping and static hyperinflation occurs. These changes can be documented by lung volume measurement as increases in functional residual capacity, residual volume and total lung capacity. Measurement of diffusing capacity (DLco) provides information on the functional impact of emphysema in COPD.