Prognostic Value of 48-h Biomarker Changes in Sepsis Mortality

Background: Sepsis remains a major cause of morbidity and mortality in intensive care units (ICUs). Although various scoring systems and biomarkers have been studied, the prognostic significance of early dynamic changes in laboratory parameters remains unclear. This study aimed to investigate the prognostic value of 48 h changes in routinely monitored biomarkers for in-hospital mortality in septic patients. Methods: This retrospective, single-center study was conducted in the Anesthesiology and Reanimation ICU of a tertiary teaching hospital. A total of 174 adult patients (≥18 years) diagnosed with sepsis according to SEPSIS-3 criteria between January 2017 and December 2022 were included. Laboratory data were recorded at ICU admission and after 48 h. Patients who died within 48 h or had missing follow-up data were excluded. Receiver operating characteristic (ROC) analysis and logistic regression models were used to assess the prognostic performance of clinical and laboratory parameters. Results: The median age was 71 years, and 58% of patients were male. Comorbidities were present in 76% patients, and malignancy was associated with higher mortality (p = 0.012). The overall in-hospital mortality rate was 58.6%. Inappropriate empirical antibiotic therapy significantly increased mortality risk (p = 0.001). Non-survivors had higher baseline SOFA and APACHE II scores. At 48 h, mortality was associated with increased procalcitonin, lactate, and CRP/albumin ratio and greater albumin decline. ROC analysis identified procalcitonin ≤ 28% decrease, lactate > 23% increase, albumin > 7% decrease, and CRP/albumin ratio > 31% increase as optimal cutoffs. Multivariate analysis revealed SOFA score > 6, inappropriate antibiotic therapy, procalcitonin ≤ 28% decrease, lactate > 23% increase, and platelet > 37% decrease as independent mortality predictors. The change in albumin level was included in the model but was not statistically significant. Conclusions: Forty-eight-hour biomarker changes, particularly in lactate and platelet count, may provide complementary prognostic information to baseline SOFA scores and may support early risk stratification in sepsis. These findings should be considered exploratory and require confirmation in prospective multicenter studies before clinical implementation.