Silent pandemic in intensive care units: Post-pandemic rise of extensively drugresistant Acinetobacter baumannii and Klebsiella pneumoniae in ventilator-associated pneumonia.

Introduction: In the post coronavirus disease-2019 era, as the pandemic's impact diminishes, the state of our intensive care units (ICUs) remains as crucial as the well-being of individuals. While numerous studies have explored the pandemic's effects on patients, our focus is to examine its impact on ICUs.

Materials and methods: A total of 72 patients who were admitted to the chest diseases ICU due to hypercapnic or hypoxic respiratory failure between October 2018-April 2020 and December 2022-December 2024 and who developed ventilator-associated pneumonia during their follow-up were included in our study.

Result: While Klebsiella pneumoniae and Acinetobacter baumannii cogrowth was observed in 4 of 30 patients (13.3%) pre-pandemic, it increased to 16 of 42 patients (38.1%) post-pandemic. Extensively drug-resistant (XDR) cases rose from 6 (20%) pre-pandemic to 34 (81%) post-pandemic (p< 0.001). A significant post-pandemic decline in carbapenem and beta-lactam susceptibility was noted (p< 0.001 for all). Although susceptibility to ceftazidime-avibactam, the most effective antibiotic for K. pneumoniae, decreased, the change was not statistically significant (p= 0.09). Multivariate regression analysis identified advanced age, coronary artery disease, low ejection fraction, and XDR resistance as factors increasing mortality (p= 0.03, 0.04, 0.04, 0.001, respectively).

Conclusions: During the pandemic, our ICU, where patients were treated with broad-spectrum antibiotics for a long time, has cured many patients but could not prevent the development of multi-drug resistance and XDR Acinetobacter and Klebsiella. Failure to take the necessary precautions will cause significant effects of the silent pandemic.