BACKGROUNDS In patients with cardiac surgery under cardiopulmonary bypass (CPB), postoperative inflammation is a driver of adverse outcomes. Endotoxaemia is one of the factors thought to trigger this inflammatory response. The mechanism behind high endotoxin activity (increased translocation vs. reduced inactivation capacity) has never been elucidated and may imply different therapeutic candidates. OBJECTIVES We aimed to evaluate, in patients with cardiac surgery with prolonged CPB, mechanisms and consequences of endotoxaemia and the efficacy of haemo-adsorption to reduce the endotoxin burden. DESIGN Ancillary analysis of a randomised controlled trial. Patients scheduled for cardiac surgery with prolonged CPB were assigned to receive either intra-operative haemo-adsorption or standard of care. Endotoxin mass and activity were measured before surgery, at the end of CPB, 6, 24 and 48 h after the end of surgery. SETTING Operating room, Amiens University Hospital. PATIENTS Adults scheduled for cardiac surgery under CPB with an expected CPB time more than 90 min. INTERVENTION Patients were randomised to receive either haemo-adsorption or standard care during CPB. MAIN OUTCOME MEASURES Endotoxin activity. RESULTS Two hundred and ninety-five samples from 66 patients were analysed. Following CPB, we observed a reduction in endotoxin mass accompanied by a relative increase in endotoxin activity. High postoperative endotoxin activity was associated with intra-operative dobutamine requirement, increased postoperative inflammatory biomarkers and organ injury. Endotoxin plasma concentration and activity were not lower in patients treated with haemo-adsoprtion. CONCLUSION The capacity of individuals to inactivate endotoxin rather than raw endotoxin mass (i.e. Quantity) seemed to be a determinant of endotoxin noxious effect in cardiac surgery and CBP. Haemo-adsorption was not associated with a reduction of endotoxin plasma mass or activity in patients with cardiac surgery under CPB. TRIAL REGISTRATION ClinicalTrials.gov, NCT04201119NCT04201119
Nguyen et al. (Wed,) studied this question.