Effects of the primary lung infection on outcomes in patients with severe ARDS treated with ECMO: A retrospective analysis

Martin Mirus^1,2*Lars Heubner^1,2Martin Brückner^1,2Thomas Birkner^2,3Andreas Güldner^1,2Axel Rand^1,2Mario Menk^1,2Paul Leon Petrick^1,2Hani Harb^2,4Peter Markus Spieth^1,2

• ¹Department of Anaesthesiology and Intensive Care Medicine, Faculty of Medicine and University Hospital Carl Gustav Carus, TUD Dresden University of Technology,, Dresden, Germany
• ²Technische Universitat Dresden, Dresden, Germany
• ³Universitatsklinikum Carl Gustav Carus Zentrum fur Evidenzbasierte Gesundheitsversorgung, Dresden, Germany
• ⁴Institute for Medical Microbiology and Virology, Faculty of Medicine and University Hospital Carl Gustav Carus, TUD Dresden University of Technology, Dresden, Germany

Introduction: Acute respiratory distress syndrome (ARDS) requiring veno-venous extracorporeal membrane oxygenation (vvECMO) remains associated with high mortality. Whether etiology-based differentiation within infectious ARDS improves prognostic and therapeutic precision remains unclear. This study compared vvECMO-treated ARDS patients with different pulmonary infections to identify clinically relevant etiology-specific differences. Methods: The retrospective single-center cohort study included adult patients who received vvECMO for severe infectious pulmonary ARDS between 2014 and 2021. Patients were categorized into Covid-19 (n=48) and Non-Covid (n=44). Clinical parameters, disease progression, treatment, and outcomes were compared. Cox and modified Poisson regression analyses identified predictors of ICU mortality. Results: Non-Covid ARDS patients had greater disease severity at ECMO initiation, although mortality was lower: SOFA score (15.7 vs. 13.7; p=0.003); PRESERVE score (3.73 vs. 2.73; p=0.004). In Covid-19 ARDS, age ≥60 years (RR 1.62), early SOFA score worsening (RR 1.17), new renal replacement therapy (RR 1.60), and septic shock (RR 3.33) were associated with increased mortality, whereas these factors were not predictive in Non-Covid ARDS. Red blood cell transfusion was associated with reduced mortality in both groups (HR 0.96 and 0.95), while fresh frozen plasma transfusion increased mortality exclusively in Covid-19 ARDS (HR 1.09). A rising SOFA score within five days after ECMO initiation predicted mortality only in the Covid-19 cohort (RR 1.17). Conclusions: Even within primary infectious pulmonary ARDS, substantial heterogeneity exists. The underlying infection critically affects the prognostic value of clinical parameters, organ dysfunctions, and scoring systems in vvECMO-treated patients. Considering ARDS etiology may improve risk stratification and guide individualized therapy