Discriminative power of organ-specific SOFA assessment in burn sepsis: A temporal biomarker analysis.

Abstract

Severe burn patients face diagnostic challenges in distinguishing sepsis from systemic inflammation using Sepsis-3 criteria. Current Sequential Organ Failure Assessment (SOFA) validation studies focus on composite scores, neglecting subsystem-level analysis in burn-specific pathophysiology. This retrospective cohort study analyzed 55 severe burn patients (TBSA>30 %) from a Chinese burn center (2021-2022), comparing 19 sepsis cases with 36 controls. We analyzed SOFA subsystems and biomarkers (creatinine, platelet count, NT-proBNP, and PCT) during both the early phase (days 1 and 3 post-burn) and the late phase (after day 3 post-burn), performed TBSA-adjusted logistic regression, and constructed a nomogram. Cardiovascular (84.2 % vs 2.8 %, p < 0.001), renal (31.6 % vs 0 %, p < 0.001), and coagulation (42.1 % vs 5.6 %, p < 0.001) subsystems showed superior diagnostic specificity. Platelet trajectories revealed critical divergence at day 3 (septic: 66 vs control: 120 ×10⁹/L, p < 0.001), while creatinine elevation persisted across phases (day 1: 100 vs 62 μmol/L, p < 0.001, day 3: 84 vs 65 μmol/L, and late phase: 118 vs 58μmol/L, p < 0.001). PCT demonstrated isolated diagnostic utility confined to the late phase (6.12 vs 0.55 μg/L, p < 0.001). Day 3 platelet count, late-phase creatinine, and PCT were incorporated into the nomogram, which achieved an AUC of 0.930 in ROC analysis. Subsystem-specific SOFA analysis identifies creatinine elevation and thrombocytopenia as key sepsis indicators in burns. Serial platelet and creatinine monitoring from day 3 post-injury enhances early detection, while PCT demonstrates diagnostic utility only in the late phase. A clinically applicable nomogram was developed to predict sepsis risk. These findings suggest that these specific organ systems are the principal contributors to the SOFA score in burn-related sepsis.