Background: The interest in protective ventilation strategies and individualized approaches for patients with severe illness on veno venous extracorporeal support has increased in recent years. Wide heterogeneity exists among patients with COVID-19 related acute respiratory distress syndrome (C-ARDS) and ARDS from other etiologies (NC-ARDS). EIT is a useful tool for the accurate analysis of regional lung volume distribution and allows for a tailored ventilatory setting. The aim of this work is to retrospectively describe the results of EIT assessments performed in patients C-ARDS and NC-ARDS undergoing V-V ECMO support. Methods: A clinical EIT-guided decremental PEEP trail was conducted for all patients included in the study and mechanically ventilated. Results: 12 patients with C-ARDS and 12 patients with NC-ARDS were included in the study for a total of 13 and 18 EIT evaluations, respectively. No significant differences in arterial blood gas, respiratory parameters, and regional ventilation before and after the EIT exam were recorded. The subset of patients with NC-ARDS whose EIT exam led to PEEP modification was characterized by a lower baseline compliance compared with the C-ARDS group: 18 (16–28) vs. 27 (24–30) (p = 0.04). Overdistension significantly increased at higher steps only for the NC-ARDS group. A higher percentage of overdistension was described in patients with NC-ARDS when compared with patients with C-ARDS. Conclusions: EIT is feasible in patients with COVID-19-associated ARDS on veno-venous extracorporeal support and may help in tailoring the PEEP setting. Overall, severe COVID-19-related ARDS presents respiratory characteristics similar to severe “classical” NC-ARDS. However, C-ARDS is associated with a lower risk of overdistension at a higher PEEP level compared with NC-ARDS.

Acute kidney injury (AKI) is a common and serious complication of cardiac surgery, often linked to the use and duration of cardiopulmonary bypass (CPB). The Hemolysis Index (HI) has been proposed as a surrogate marker of hemolysis and a potential predictor of cardiac surgery-associated AKI (CS-AKI). This study was designed to evaluate the associations between CPB time and HI with the onset of CS-AKI. An observational cohort study; retrospective analysis of prospectively collected data. A single-center, Italian university tertiary care hospital. Patients admitted to the cardiothoracic intensive care unit (ICU) following cardiac surgery between 2019 and 2023. HI was measured at ICU admission. CS-AKI and its severity were defined using the Kidney Disease: Improving Global Outcomes creatinine-based criteria. Associations between HI, CPB duration, and CS-AKI were assessed using logistic regression analyses, adjusting for the Cleveland Clinic Score. A total of 1,195 patients were included in the analysis. Median age was 70 years (interquartile range [IQR] 62-75), and 310 patients (26%) were female. Median CPB duration was 110 minutes (IQR 80-140), and median HI at ICU admission was 25 (IQR 15-42). HI showed a moderate correlation with CPB duration (r = 0.367, p < 0.001). CS-AKI occurred in 103 patients (9%). In multivariable analysis, both HI and CPB time were independently associated with CS-AKI (odds ratio per 10-unit increase in HI 1.52, 95% confidence interval 1.04-2.18, p = 0.027; odds ratio per hour of CPB 1.32, 95% confidence interval 1.08-1.63, p < 0.001). HI and CPB time were independently associated with CS-AKI. The utility of incorporating these parameters into CS-AKI predictive models warrants further evaluation.