Prevalence, Risk Factors, and Antibiotic Intervention of Lower Airway Pseudomonas aeruginosa Colonization in Patients with Stable Chronic Obstructive Pulmonary Disease: a Systematic Review and Meta-Analysis.

Background and objectives: Bacterial colonization or chronic infection occurs in the lower respiratory tract of patients with chronic obstructive pulmonary disease (COPD). Previous studies on Pseudomonas aeruginosa (PA) colonization in patients with stable COPD mainly focused on its impact on prognosis, such as leading to acute exacerbations and increased mortality. However, the prevalence of PA colonization remains unknown. Evidence-based medicine is lacking regarding the association of prior antibiotics and inhaled corticosteroids (ICSs) exposure with PA colonization, intervention with antibiotic therapy for acute exacerbations, and the effect of PA eradication. We conducted this systematic review and meta-analysis to investigate these issues and inform precise treatment and prevention.

Methods: We searched PubMed, Embase, Google Scholar, Cochrane, China National Knowledge Infrastructure (CNKI), and ClinicalTrials.gov for randomized controlled trials (RCTs) and observational studies. The primary outcome was prevalence. Secondary outcomes included previous antibiotic and ICS exposure, exacerbations after antibiotic therapy, and the eradication rate of PA with inhaled antibiotics (IAs).

Results: A total of 39 studies were included, comprising 32,753 cases. The pooled prevalence was 5.6% (95% CI 0.04-0.07). Previous exposure to antibiotics and ICSs was associated with increased PA colonization, with odds ratio (OR) values of (OR = 2.85, 95% CI 1.62-5.01) and (OR = 1.89, 95% CI 1.12-3.19), respectively. Exacerbations decreased within the next year after azithromycin treatment (standardized mean difference [SMD] = -0.43, 95% CI -0.77 to -0.10). The eradication rate of PA with IAs was 0.52 (95% CI 0.46-0.57), and IAs reduced exacerbations in the following year (SMD = -0.87, 95% CI -1.38 to -0.35).

Conclusion: The prevalence of PA colonization in stable COPD was approximately 5.6%. Prior exposure to antibiotics and ICSs increased the risk of PA colonization. Azithromycin therapy reduced exacerbations in PA colonized COPD patients. The eradication rate of PA within one year after IA therapy was about 52%, and exacerbations decreased.