Sputum microbiology in patients with stabile COPD

Abstract

Introduction: Chronic bronchial infection in COPD patients is defined as presence of potential pathogenic microorganisms (PPMs) in their respiratory secrets. Aim: To assess the presence of pathogenic microorganisms in sputum of patients with stable COPD and its association with commonly used clinical variables. Matherials and methods: Medical history,physical examination,pulmonary function tests,microbiological examination of sputum(spontaneous or induced by inhalation of 4,5% NaCl),blood samples and high resolution CT of 53 patients were performed.Symptoms were assessed by questionnaire.T-test analysis, χ2-test and Pearson correlation were used as statistical methods. Results: PPMs were detected in the sputum samples of eleven patients:Pseudomonas aeruginosa(3),Streptococcuspneumoniae (2),Klebsiella spp.(2),Haemophilus spp.(2),Serratia marcescens(1),Stenotrophomonas maltophilia (1),Enterobacter agglomerans(1).Two sputum samples were positive for Candida spp. The presence of PPMs is significantly associated with CT data of bronchiectasis(Pearson χ2=15,519; p=0,001).Bronchiectasis and PPMs are strongly positively correlated (r=0,541).Pathogenic microorganisms are more often detected in patients with respiratory failure than in those with normal blood gases (Pearson9s χ2=8,500; p=0,014).There are no significant differences in age, BMI, duration of COPD, smoking burden, symptoms (according to CAT and MRC),previous exacerbations,CRP levels,pulmonary function,BODE index and 6MWT in patients with and without bronchiectasis and in patients with positive or negative sputum culture. Conclusion: The presence of pathogenic microorganisms in the sputum samples of patients with stable COPD is associated with bronchiectasis and respiratory failure.