Association of Pseudomonas Infection with Disease Severity and Exacerbations in Non-cystic Fibrosis Bronchiectasis: A Retrospective Cross-sectional Study

Background: Non-cystic fibrosis bronchiectasis (NCFB) is a chronic respiratory disease characterized by recurrent infections, progressive lung damage, and frequent exacerbations. Pseudomonas aeruginosa infection is associated with worse clinical outcomes; however, regional data on its impact on disease severity and exacerbations in Indian patients remain limited. Aims and Objectives: To evaluate the association between Pseudomonas aeruginosa infection and disease severity using the FACED score and exacerbation frequency in patients with non-cystic fibrosis bronchiectasis. Materials and Methods: This retrospective cross-sectional study was conducted at a tertiary care hospital in South India from January to December 2024. Eighty adult patients (≥18 years) with HRCT-confirmed non-cystic fibrosis bronchiectasis were included. Clinical, radiological, spirometric, and microbiological data were extracted from medical records. Patients were categorized based on the presence or absence of Pseudomonas aeruginosa in sputum culture. Disease severity was assessed using the FACED score. Statistical analysis was performed using SPSS version 23, with a p-value <0.05 considered significant. Results: A total of 80 patients were included in the study. The cohort was predominantly older, with 46.25% aged over 60 years, and females constituted 56.25% of the study population. Obstructive patterns were observed in 57.5% of spirometry results. Post-tuberculosis bronchiectasis was the most common etiology (55%), followed by idiopathic causes (23.75%). Pseudomonas aeruginosa was the most frequently isolated organism (27.5%). Based on FACED score, 53 patients (66.25%) had mild disease, while 27 patients (33.75%) had moderate to severe disease. Pseudomonas infection was significantly associated with moderate/severe disease (72.7% vs. 27.3%, P < 0.001), reduced FEV1% (67.1 ± 23.9 vs. 87.9 ± 20.4, P = 0.002), and age >60 years ( P = 0.01). Among patients with Pseudomonas aeruginosa infection, 68.2% experienced two or more exacerbations in the past year, compared to 27.6% of those without ( P =0.04). Conclusion: Pseudomonas infection is significantly associated with increased severity, impaired lung function, and frequent exacerbations in NCFB. Early identification of this high-risk phenotype through routine microbiological surveillance may facilitate timely intervention and improved clinical outcomes.