Interleukin-6 extraction ratios during prolonged CytoSorb hemoadsorption depend on procedural blood flowGubenšek, Jakob (Avtor) Vajdič Trampuž, Barbara (Avtor) Zrimšek, Matej (Avtor) Peršič, Vanja (Avtor) CytoSorbcytokineshemoadsorptioninterleukin 6 (IL6)reduction ratioremoval rateBackground: Hemoadsorption with CytoSorb is a novel treatment for cytokine release syndrome, but there are few published data on the rate of cytokine removal with prolonged use. Here, we report a prospective observational study of IL-6 extraction ratios with prolonged CytoSorb use. Methods: A secondary analysis was conducted on a prospective observational cohort study involving patients treated with CytoSorb. Blood samples for IL-6 were taken before treatment, after 30 min, and every 6 h of treatment at three sites: (1) before the adsorber, (2) between the adsorber and dialyzer, and (3) after the dialyzer. The extraction ratios of the adsorber were then calculated. Results: We included 21 dialysis circuits performed in 15 critically ill patients, mainly those with cytokine storm because of septic shock. The median extraction ratio of IL-6 after 30 min was 26% (interquartile range, IQR 18-37%). The ratio decreased to 10% (6-21%) after 6 h and remained between 9-16% for up to 24 h (with a low number of circuits used beyond 12 h). Extraction ratios were similar in circuits with high (>1,000 ng/L) and low baseline IL-6 levels. On the contrary, in circuits with high blood flow (≥200 mL/min, i.e., intermittent hemodialysis), the extraction ratio was very low (median 6%) at 6 h and negligible thereafter, whereas the circuits with lower blood flow (<200 mL/min) maintained an extraction ratio of 20% for up to 12 h. Conclusion: We observed a significant reduction in the IL-6 extraction ratio within 6 h in circuits with high blood flow, whereas circuits with lower blood flow maintained an adequate extraction ratio for up to 12 h. Recent consensus recommendations on an 8-12 h exchange interval should mainly be applied to continuous dialysis methods, whereas in intermittent hemodialysis, the exchanges should be more frequent.20252026-01-13 08:24:40Neznano25165sl