Supplementary Material for: Clinical Effect of the Acrylonitrile-Co-Methallyl Sulfonate Surface-Treated Membrane as a Cytokine Adsorption Therapy for Sepsis due to Acute Panperitonitis: A Retrospective Cohort Study

Introduction: Sepsis is a systemic inflammatory response syndrome caused by infectious diseases, with cytokines possibly having an important role in the disease mechanism. Acrylonitrile-co-methallyl sulfonate surface-treated (AN69ST) membrane is expected to improve the outcomes of patients with sepsis through cytokine adsorption. Objective: This study aimed to investigate the clinical effect of the AN69ST membrane in comparison to standard continuous renal replacement therapy (CRRT) membranes for panperitonitis due to lower gastrointestinal perforation. Methods: Using the Diagnosis Procedure Combination database, we identified adult patients with sepsis due to panperitonitis receiving any CRRT. Propensity score matching was used to compare patients who received CRRT with the AN69ST membrane (AN69ST group) and those who received CRRT with other membranes (non-AN69ST group). The primary outcome measure was in-hospital mortality. Results: A total of 528 and 1,445 patients were included in the AN69ST group and in the non-AN69ST group, respectively. Propensity score matching resulted in 521 pairs. There was no significant difference in in-hospital mortality (32.1 vs. 35.5%; p = 0.265) and 30-day mortality (41.3 vs. 42.8%, p = 0.074) between the AN69ST group and the non-AN69ST group. Conclusion: There is no significant difference in-hospital mortality between CRRT with the AN69ST membrane and CRRT with standard CRRT membranes for panperitonitis due to lower gastrointestinal perforation. These results indicate that the AN69ST membrane is not superior to the standard CRRT membrane.