The Contribution of Carbapenem-Resistant Pseudomonas Aeruginosa Isolation to Clinical Outcomes in Hospitalized Patients with Exacerbations of Bronchiectasis: A Retrospective Cohort Study.

Background: The antibiotic resistance of Pseudomonas aeruginosa (PA) is increasingly severe in bronchiectasis patients. However, there is currently a lack of research on the clinical outcomes of carbapenem-resistant PA (CRPA) isolation in hospitalized exacerbations of bronchiectasis (HEB) patients. We investigated the incidence, risk factors, and clinical outcomes of PA and CRPA isolation in HEB patients.

Methods: This was an observational, retrospective cohort study of PA and CRPA isolated from sputum or bronchoalveolar lavage fluid cultures of HEB patients from January 1, 2018 to December 31, 2022. The primary outcomes were respiratory failure, mechanical ventilation, and length of hospital stay. The incidence, risk factors, and clinical outcomes of PA and CRPA isolation were analyzed using multivariate logistic and Poisson regression.

Results: Among 1,286 patients, the prevalence of PA, CRPA, and multi-drug resistant PA isolation was 20.61% (n = 265), 3.81% (n = 49), and 5.83% (n = 75), respectively. CRPA isolation was associated with an increased risk for respiratory failure (adjusted odds ratio (aOR) 2.56; 95% confidence interval (CI) [1.29, 5.11]; p = 0.007), mechanical ventilation (aOR 3.65; 95% CI [1.50, 8.92]; p = 0.004), and length of hospital stay (Coefficient (Coef) 0.27; 95% CI [0.18,0.35]; p < 0.001) compared to non-CRPA. Antibiotic treatment decreased the risk of respiratory failure (aOR 0.37; 95% CI [0.17, 0.80]; p = 0.011), mechanical ventilation (aOR 0.36; 95% CI [0.13, 0.99]; p = 0.047), and length of hospital stay (Coef - 0.23; 95% CI [- 0.33, - 0.14]; p < 0.001).

Conclusions: CRPA isolation was identified in more severe bronchiectasis patients and significantly increased the risk of respiratory failure, mechanical ventilation and length of hospital stay, while antibiotic treatment reduced this risk.