Predicting factors for chronic colonization of Pseudomonas aeruginosa in bronchiectasis.

About 25% of the patients with bronchiectasis are likely to develop a chronic colonization with Pseudomonas aeruginosa. A better understanding of predictors of acquiring Pseudomonas within the patient population may facilitate future focused research. The aim of this retrospective observational study was to investigate predicting factors for P. aeruginosa colonization in patients with bronchiectasis. This was a single-center retrospective cohort study using a bronchiectasis database which consisted of 211 patients with bronchiectasis. Data were collected for demographic details, etiology, spirometry, microbiology data, maintenance medication use, exacerbation frequency, hospital admission rate, and FACED and Bronchiectasis Severity Index (BSI) score. Two hundred eleven patients were identified from our bronchiectasis database. Overall, 25% of the patients (n = 53) had a chronic colonization with P. aeruginosa. Seventeen patients (8%) died in a 5-year follow-up period of whom 7 (41%) had a chronic P. aeruginosa colonization (p > 0.05). After multiple regression analysis, P. aeruginosa-positive patients were significantly associated with an older age (> 55 years) (p = 0.004), the use of hypertonic saline (0.042), and inhalation antibiotics (< 0.001). Furthermore, the presence of PCD (p < 0.001) and post-infectious etiology (p < 0.001) as underlying causes were significantly associated with P. aeruginosa colonization. We observed that independent predictors for P. aeruginosa colonization were age > 55 years, hypertonic saline, and PCD, and post-infectious etiology as underlying causes of bronchiectasis. Since prevention of P. aeruginosa colonization is an important aim in the treatment of bronchiectasis, more attention could be directed to these groups at risk for Pseudomonas colonization.