The impact of carbapenem-resistant infections in intensive care units: focus on non-fermenting gram-negative bacilli and survival analysis

Abstract

Objectives: Carbapenem-resistant non-fermenting Gram-negative bacilli (CR Nf-GNB) infections present a significant challenge in intensive care units (ICUs). Despite being recognized as a significant clinical problem, comprehensive studies on the impact of CR Nf-GNB infections on patient morbidity and mortality remained limited. Methods: Using data from the REA-REZO surveillance network, which includes 206 adult ICUs in France, we analysed patients admitted between 2016 and 2022 who developed healthcare-associated infections caused either by CR Nf-GNB or carbapenem-susceptible (CS) Nf-GNB. Propensity scores were calculated using a logistic regression model including relevant covariates, and CR and CS Nf-GNB patients were matched 1:1. The primary outcome was 30-day ICU survival, and secondary outcomes included 30-day reinfection (different pathogen) and relapse (same pathogen) rates. Results: Among the 17,527 Nf-GNB infections, 3,171 were caused by CR strains. After matching, 1,498 patients were included in each group. CR Nf-GNB infections were independently associated with a significantly higher risk of death (adjusted sub-Hazard Ratio [sHR] 1.57 [95% CI, 1.40–1.76]) and increased reinfection rates (sHR 1.23 [95% CI, 1.01–1.50]) compared to CS Nf-GNB infections. CR infections also showed a higher proportion of reinfections with multidrug-resistant organisms. Conclusion: CR Nf-GNB infections in ICU patients significantly increased mortality, and the risk of reinfection. CR Nf-GNB was not associated with a higher risk of relapse. These findings underscore the importance of targeted infection control measures and novel treatment strategies to manage CR Nf-GNB in critical care settings.