Report On Complete Endpoints and Predictors of Response to Plasma Exchange – Results From a Randomized Controlled Trial in Septic Shock Patients

Background: Recently, a randomized controlled trial (RCT) demonstrated rapid but individually variable hemodynamic improvement with therapeutic plasma exchange (TPE) in patients with septic shock. Prediction of clinical efficacy in specific sepsis treatments is fundamental for individualized sepsis therapy.Methods: In the original RCT patients with septic shock of < 24 h duration and norepinephrine (NE) requirement ≥ 0.4 μg/kg/min received standard of care (SOC) or SOC + one single TPE. Here we report all clinical and biological endpoints of this study. Subgroup analysis of NE reduction and 28-day mortality was performed to investigate characteristics that could be associated with clinical response.Results: Early hemodynamic stabilization was preserved in the TPE group for 24 hours and was accompanied by a reduction of lactate suggestive for shock reversal. A reduction of injurious mediators (such as PCT, vWF:Ag, Angpt-2, sTie-2) and a repletion of exhausted protective factors (such as AT-III, Protein C, ADAMTS-13) could be observed in the TPE but not in the SOC group. Significant NE reduction (> 50% from baseline) upon TPE occurred more often in patients with 1) a pulmonary focus of infection, 2) profound respiratory failure (pO2/FiO2<150 mmHg), 3) critical hemodynamic instability (NE > 0.6 μg/kg/min and lactate >0.4 mmol/l) as well as 4) substantial degree of organ failure (SOFA Score > 16) at randomization. Patients with a pulmonary focus of infection had a 28-day mortality of 15% in the TPE group while it was 42% in the SOC group. Conclusions: Adjunctive TPE is associated with the removal of injurious mediators and repletion of consumed protective factors altogether leading to preserved hemodynamic stabilization in refractory septic shock. It is We identified potential response predictors (lung focus, PF ratio < 150, higher SOFA score etc.) that might guide future designing of large RCTs that will further evaluate TPE with regard to hard endpoints. Trial registration: Retrospectively registered 18th January 2020 at clinicaltrials.gov (Identifier: NCT04231994), https://clinicaltrials.gov/ct2/show/NCT04231994?term=NCT04231994&draw=2&rank=1