Changes in Hemogram-Derived Ratios in Patients with Sepsis Undergoing Cytokine-Filtered Continuous Renal Replacement Therapy in the Intensive Care Unit: A Retrospective Single-Center Study.

BACKGROUND Background: Hemogram-derived indices, including the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR), are widely used for diagnostic and prognostic purposes in critically ill patients. However, these indices may be influenced not only by disease processes but also by therapeutic interventions such as cytokine-filtered continuous renal replacement therapy (CRRT). This study aimed to evaluate temporal changes in NLR and PLR in patients with sepsis undergoing cytokine-filtered CRRT. MATERIAL AND METHODS Material and Methods: Data from 93 intensive care unit patients who received cytokine-filtered CRRT between January 2020 and December 2022 at a single tertiary care center were retrospectively reviewed. Hemogram values were recorded at baseline (Day 0) and on Days 1, 2, and 3. The primary outcome was the change in PLR; secondary outcomes included changes in NLR and other hematologic parameters. Statistical analyses were performed using repeated measures analysis of variance and regression modeling. RESULTS Results: PLR significantly decreased from Day 0 to Days 2 and 3 (P CONCLUSIONS Conclusions: NLR and PLR are sensitive to cytokine-filtered CRRT and may reflect treatment-related effects, rather than disease progression. Careful consideration of the timing and clinical context of laboratory sampling is essential when interpreting these indices in intensive care unit settings.