Retrospective evaluation of cytokine filter use in intensive care unit patients

Aim; This study aimed to retrospectively evaluate the hemodynamic, clinical, and biochemical changes observed in patients diagnosed with sepsis who received cytokine filter therapy in the intensive care unit. Materials and Methods; A total of 91 patients followed in the Internal Medicine Intensive Care Unit of Pamukkale University Hospital between 2021 and 2023 with a diagnosis of sepsis and who underwent renal replacement therapy with a sepsis filter were retrospectively analyzed.Demographic characteristics, comorbidities, sources of sepsis, and microbiological findings were recorded. Patients were divided into subgroups according to fever phenotype and type of renal replacement therapy—continuous renal replacement therapy (CRRT) or intermittent hemodialysis (HD).Clinical scores (GCS, SOFA), hemodynamic parameters (mean arterial pressure, norepinephrine dose, urine output), and laboratory values were evaluated at 0, 24, and 48 hours. Results; The mean age of the patients was 65.9 ± 15.2 years, and 60.4% (n=55) were male. The most common comorbidities were chronic kidney disease (33.0%, n=30), malignancy (30.8%, n=28), and hypertension (29.7%, n=27). The predominant focus of sepsis was pneumonia/ARDS (67.0%, n=61), and Gram-negative bacterial growth was detected in 54.9% (n=50) of cultures. During the first 48 hours, mean arterial pressure (MAP) significantly decreased within the first 24 hours (p=0.023) and increased again at 48 hours (p=0.007). Norepinephrine dose increased at 24 hours (p<0.001) and tended to decrease by 48 hours. Urine output decreased significantly at 24 hours and increased markedly at 48 hours (p<0.001). Renal function improved, as evidenced by reductions in creatinine and BUN levels and an increase in GFR (all p≤0.001). CRP levels decreased significantly at 48 hours (p<0.001), while procalcitonin levels showed a transient rise at 24 hours (p=0.006). In subgroup analysis, the hypothermic fever phenotype was associated with higher lactate levels (p=0.013), lower urine output (p=0.048), and greater norepinephrine requirements (p=0.034). When analyzed according to renal replacement modality, CRRT patients showed higher norepinephrine, lactate, and INR levels (p≤0.007), whereas HD patients maintained higher urine output (p≤0.030). Differences in electrolyte (Na, Ca, Mg; p≤0.045) and liver function parameters (AST, ALT; p≈0.01–0.017) indicated distinct physiological impacts of the two treatment modalities. Conclusion; In critically ill patients treated with a sepsis adsorption filter, significant improvements were observed in hemodynamic and biochemical parameters within the first 48 hours. The fever phenotype was found to be associated with clinical course; particularly, the hypothermic phenotype was linked to higher lactate levels and increased vasopressor requirements, which may reflect a more severe inflammatory response. The use of a sepsis filter appears to be a beneficial therapeutic approach for achieving hemodynamic stability, preserving organ functions, and supporting clinical recovery. However, treatment strategies should be individualized according to each patient's clinical characteristics, hemodynamic status, and infection response, as this personalized approach may enhance treatment efficacy and reduce the risk of complications in sepsis management.