Pseudomonas aeruginosa infection increases the readmission rate of COPD patients

Choi, Juwhan; Oh, Jee Youn; Lee, Young Seok; Hur, Gyu Young; Lee, Sung Yong; Shim, Jae Jeong; Kang, Kyung Ho; Min, Kyung Hoon

In our study, P. aeruginosa is the most commonly identified pathogen. However, in a previous study, the most commonly identified bacteria in AECOPD are S. pneumoniae, H. influenzae, and Moraxella catarrhalis. 23 There are some reasons for this discrepancy. First, the COPD grade in our study is high. P. aeruginosa is most commonly identified in patients at GOLD stages III and IV. 24 Meta-analysis has shown that P. aeruginosa identification is statistically higher in COPD patients with bronchiectasis. 25 The identification of P. aeruginosa means that the host belongs to the highrisk group. Second, it is a regional characteristic. Unlike the Western study, some studies in Korea and Asia show that P. aeruginosa is most commonly identified. 26, 27 There are two clinical features when P. aeruginosa is identified in AECOPD patients. 28 The most common feature is carriage of P. aeruginosa for a short time followed by clearance (,1 month) . The other feature is persistent colonization with P. aeruginosa. There is a debate regarding the prognosis and mortality of stable COPD patients who are colonized by P. aeruginosa. 29 There is no clear evidence that antibiotics should be used in this condition. A prospective study showed that P. aeruginosa identification in patients with severe AECOPD was associated with a higher 3-year mortality rate. 30 Chronic P. aeruginosa infection has also been shown to increase the mutation rate and antibiotic resistance of proteases and reduce their production. 31 Although there is controversy regarding P. aeruginosa infections in patients with stable COPD,