Purpose: Carbapenem-resistant Klebsiella pneumoniae (CRKP) is closely related to respiratory tract infection. The aim of this study was to investigate the clinical features and prognostic factors of CRKP-induced pneumonia in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients.
Methods: A single-centre, retrospective case-control study on COPD patients hospitalized for acute exacerbation and CRKP-induced pneumonia was conducted from January 1, 2016, to December 31, 2022. The mortality rate of acute exacerbation due to CRKP-induced pneumonia was investigated. The patients were divided into the CRKP-induced pneumonic acute exacerbation (CRKPpAE) group and the non-CRKP-induced pneumonic acute exacerbation (non-CRKPpAE) group, and the clinical characteristics and prognostic factors were compared using univariate analysis and multivariate analysis.
Results: A total of 65 AECOPD patients were included, composed of 26 patients with CRKPpAE and 39 patients with non-CRKPpAE. The mortality rate of CRKPpAE was 57.69%, while non-CRKPpAE was 7.69%. Compared with non-CRKPpAE, a history of acute exacerbation in the last year (OR=8.860, 95% CI: 1.360– 57.722, p=0.023), ICU admission (OR=11.736, 95% CI: 2.112– 65.207, p=0.005), higher NLR levels (OR=1.187, 95% CI: 1.037– 1.359, p=0.013) and higher D-dimer levels (OR=1.385, 95% CI: 1.006– 1.905, p=0.046) were independently related with CRKPpAE. CRKP isolates were all MDR strains (26/26, 100%), and MDR strains were also observed in non-CRKP isolates (5/39, 12.82%).
Conclusion: Compared with non-CRKPpAE, CRKPpAE affects the COPD patient’s condition more seriously and significantly increases the risk of death.

Keywords: chronic obstructive pulmonary disease, acute exacerbation, carbapenem-resistant K. pneumoniae, pneumonia