EAA-Guided AN69-oXiris and PMX-HP Therapy in Septic Patients

Sepsis and septic shock are life-threatening conditions in which the body's response to infection can cause dangerously low blood pressure and organ failure. In some patients with an infection inside the abdomen, severe inflammation may continue even after emergency surgery or another procedure has controlled the source of infection. Endotoxin is a substance produced by certain bacteria that may worsen this inflammation. The Endotoxin Activity Assay is a blood test that estimates how strongly endotoxin is affecting the body. This study will compare two blood purification treatments, AN69-oXiris and polymyxin B hemoperfusion (PMX-HP), in patients receiving intensive care for sepsis or septic shock caused by an intra-abdominal infection. Blood purification removes blood through a central venous catheter, passes it through a special filter or cartridge, and then returns it to the body. These treatments are intended to reduce endotoxin or other substances involved in inflammation. The study plans to enroll 50 participants at Seoul St. Mary's Hospital. Participants will be assigned by chance, in a 1:1 ratio, to receive either AN69-oXiris or PMX-HP. Participants and the clinical team will know which treatment is used.

Inclusion Criteria: * Participants must meet all of the following criteria: 1. Adults aged 18 years or older. 2. Diagnosis of sepsis or septic shock caused by an intra-abdominal infection, including peritonitis, according to the Sepsis-3 criteria. 3. Completion of emergency surgery for infection source control, with successful surgical control of the infection source. 4. Admission to the surgical intensive care unit (SICU) for postoperative intensive care. 5. Ability to undergo measurement of endotoxin activity (EA) using the Endotoxin Activity Assay (EAA). 6. Determination by a critical care specialist that extracorporeal blood purification therapy with either AN69-oXiris or PMX-HP is clinically indicated. 7. Ability to obtain central venous access and undergo extracorporeal blood purification therapy. 8. Provision of voluntary written informed consent by the participant or the participant's legally authorized representative after receiving sufficient information about the study. Exclusion Criteria: * Participants meeting any of the following criteria will be excluded: 1. Younger than 18 years of age. 2. Surgical source control of the infection was not performed or was considered incomplete. 3. Pregnant or breastfeeding. 4. Refusal to participate in the study or inability to obtain informed consent from a legally authorized representative. 5. Concurrent participation in another clinical study.