Infection risks in patients treated by continuous renal replacement therapy and extracorporeal membrane oxygenation

This review addresses the growing concern over nosocomial infections in patients undergoing extracorporeal membrane oxygenation (ECMO) and/or continuous renal replacement therapy (CRRT). As the use of these modalities increases, particularly in critically ill patients, infection-related complications remain frequent, underdiagnosed, and inadequately addressed in existing guidelines. This review is timely given the urgent need to standardize diagnostic and preventive strategies in this high-risk population.

Recent studies highlight the multifactorial origin of infection risk in ECMO/CRRT patients, including device-related immunoparalysis. In patients on ECMO, nosocomial infections - particularly ventilator-associated pneumonia (VAP), bloodstream infections (BSIs), and cannula-related infections (CRIs) - are among the most frequent complications, with incidence rates ranging from 9% to 64%. VAP and BSIs occur at rates up to 61 and 38 per 1000 ECMO-days, respectively. Predominant pathogens include Enterobacterales, nonfermenting Gram-negative bacilli, Enterococcus spp., and fungi. Enterococcus-related BSIs are notably underrecognized and often inadequately treated. Duration of ECMO support is the most consistent infection risk factor, along with illness severity and CRRT co-initiation. Nosocomial infections are associated with a 32% relative increase in mortality.

Nosocomial infections in ECMO/CRRT patients are common, diagnostically challenging, and strongly linked to poor outcomes. Their prevention and management require an integrated, tailored strategy. Standardized definitions, improved surveillance, and targeted antimicrobial stewardship are urgently needed to mitigate risks in this vulnerable population.