This randomized controlled trial evaluates the efficacy of intraoperative haemoadsorption (HA) using CytoSorb® during cardiac surgery with cardiopulmonary bypass (CPB). The primary focus was on reducing interleukin-6 (IL-6) levels post-surgery. Despite a significant reduction in cytokine levels within the HA device during surgery, there was no difference in IL-6 levels between the treatment and control groups upon ICU admission or during the ICU stay. Some haemodynamic benefits, such as reduced fluid and fibrinogen requirements and shorter need for renal replacement therapy, were observed, though these did not translate into improved clinical outcomes like ICU length of stay or mortality rates. The study underscores the need for further large-scale trials to refine patient selection and HA application strategies.