Inclusion Criteria:  diagnosed with COPD stages I-IV with acute exacerbations incompetence to use medication by mouth fever antibiotic usage for longer than 1 day treatment with systemic administration of corticosteroids signs of pneumonia on radiographs history of mechanical ventilation during acute exacerbations of COPD in the past  Exclusion Criteria:  recently detected or unresolved pulmonary malignancy other infectious diseases requiring antibiotic treatment kidney failure