Clinical Microbiology and Antimicrobial Chemotherapy. 2005; 7(3):245-254
To study the microbial and susceptibility patterns in COPD patients with acute respiratory failure (ARF) we performed a prospective cohort study in patients with ARF admitted to our acute care hospital. Quantitative cultures of expectorated sputum or bronchoalveolar lavage fluid (BALF) were performed. Patients with pneumonia and other causes of ARF were analyzed separately and were excluded from the study. One hundred seven COPD patients were included (92 males, age=66±8 years; APACHE II score=19±6; pH=7.27±0.07; PaCO2=61±15 mm Hg; PaO2=49±9 mm Hg), 70 patients received noninvasive ventilation and 18 patients – mechanical ventilation. Sputum or BALF culture diagnosed bacteriarelated exacerbation in 73 (68%) of participating COPD patients. Pathogens most frequently isolated were Pseudomonas spp. (29%), Haemophilus influenzae and Haemophilus parainfluenzae (20%), Streptococcus pneumoniae (14%). 90% of S. pneumoniae strains were sensitive to penicillin; Pseudomonas species revealed multiresistance in 19%. Multivariate logistic regression analysis showed that the only factor independently associated with isolation of Pseudomonas spp. was the frequency of hospitalizations – more than 4 times (OR 4.04, 95%CI 1.20–13.56, p=0.024).