Results: Mortality prognostic factors in acute exacerbation of COPD were the frequency of acute exacerbation with higher three times, patient's medical history with non-corticosteroid therapy, unwell-controlled COPD, administered antibiotics, perceptual disorders, right-sided heart failure complications, abnormal respiratory rates of more than 35 or less than 18 breaths per minute, severe respiratory failure, grade 4 of MRC breathlessness scales, cyanosis exhibition, increased level of serum CRP, decreased blood pH, elevated blood PaCO2, lower FEV1 values ​​ (p < 0.005).