Impact of different extracorporeal blood purification strategies during continuous renal replacement therapy in septic shock patients

Septic shock with acute kidney injury is associated with high mortality. Hemoadsorption methods such as CytoSorb Ⓡ in conjunction with standard continuous renal replacement therapy (CRRT) and oXiris Ⓡ -based CRRT are increasingly used; however, comparative data are scarce. This study assessed the effects of both filters on vasopressor-free days and key clinical outcomes in septic shock. This retrospective single-center cohort included adults with septic shock treated with CytoSorb Ⓡ in conjunction with CRRT or oXiris Ⓡ -based CRRT between January 2023 and December 2024. The primary endpoint was vasopressor-free days to day 28, with secondary outcomes including Sequential Organ Failure Assessment (SOFA) score, lactate levels, norepinephrine equivalent dose (NEED), mean arterial pressure, ventilator-free days, intensive care unit (ICU) length of stay, and mortality. A total of 97 patients were included in the analysis. (CytoSorb Ⓡ n =75; oXiris Ⓡ n =22). Both extracorporeal blood purification modalities were associated with comparable reductions in lactate levels (median [IQR]: −39.7 [−47.2 to −19.3]% vs. 44.5 [−54.0 to −33.3] %, respectively, P =0.14), and NEED (median [IQR]: −36.1 [−66.7 to −9.1] vs. −56.4 [−83.3 to −12.5] %, respectively, P =0.36), along with similar increases in mean arterial pressure (9.6 [7.7–18.2]% vs. 9.8 [7.7–16.7] %, respectively, P =0.94). No significant differences were found between the two modalities. Vasopressor-free days were similar (median [IQR]: 0.0 [0–24] days with CytoSorb Ⓡ vs. 20.5 [0–25] days with oXiris Ⓡ , P =0.55). In the multivariable competing-risks analysis, extracorporeal blood purification modality was not independently associated with vasopressor-free days after adjustment for potential confounders (subhazard ratio [sHR]=0.97, 95% confidence interval: 0.48–1.94, P =0.93). Ventilator-free days, ICU stay, and ICU and hospital mortality were likewise comparable. CytoSorb Ⓡ in addition with CRRT and oXiris Ⓡ -based CRRT demonstrated similar hemodynamic and clinical outcomes. Larger prospective studies are needed to define the optimal role of extracorporeal CRRT-based blood purification in septic shock.