Retrospective Analysis of Fungal Isolations in Patients on Veno-Venous Extracorporeal Membrane Oxygenation: The Multicenter RANGER STUDY 2.0

<b>Background:</b> Veno-venous extracorporeal membrane oxygenation (V-V ECMO) represents a progressively adopted life-sustaining intervention worldwide, particularly in the management of acute respiratory distress syndrome. Nevertheless, data concerning the prognostic significance of fungal isolation in this setting remain unclear. This study aims (i) to assess the incidence of fungal infection and colonization in a homogeneous cohort of V-V ECMO patients, and (ii) to evaluate the association between fungal infection or colonization and 1-year mortality, with a focus on the impact of specific fungal species. <b>Methods:</b> All consecutive adults admitted to the Intensive Care Units of five Italian university-affiliated hospitals and requiring V-V ECMO were screened. Exclusion criteria were age < 18 years, pregnancy, veno-arterial or mixed ECMO-configuration, incomplete records and survival < 24 h after V-V ECMO placement. A standard protocol of microbiological surveillance was applied and the distinction between different fungal species were made through in vivo and vitro tests. Cox-proportional hazards models, Kaplan-Meier curves and linear logistic regressions were applied for investigating mortality. <b>Results:</b> Two-hundred and seventy-nine V-V ECMO patients (72% male) were enrolled. The overall fungal isolation was 41% (n. 114): 23% infections and 18% colonizations. The overall 1-year mortality, among fungal isolations, was 40%, with no different risk in case of fungal infection (26 out of 63, 41%) (aHR 0.85, 95% CI [0.53-1.37], <i>p</i>-value 0.505) and colonization (20 out of 51, 39%) (aHR 0.86, 95%CI [0.51-1.43], <i>p</i>-value 0.556), as compared to patients never detecting fungi (68 out of 165, 41%, <i>reference</i>). According to the isolated mycotic species, as compared to <i>Candida</i> sp. group (<i>reference</i>), the risk of death was greater when different fungal species (e.g., <i>Aspergillus</i> sp. and <i>Candida</i> sp.) were concomitantly isolated in the same patient (OR 1.17, 95%CI [1.12-11.07], <i>p</i>-value 0.031. <b>Conclusions:</b> In the overall population, 23% V-V ECMO patients recorded 'late' fungal infections and 18% fungal colonizations, with a similar risk of death as compared to patients never experiencing fungi during the V-V ECMO course. The detection of concomitant different fungal species was an independent risk factor for 1-year mortality.