A Coupled Inflammation-Metabolism Index for Early Prediction of Organ Dysfunction Progression Within 24 h After ICU Admission in Septic Shock.

BACKGROUND: Early progression of organ dysfunction is common in septic shock and is closely associated with poor outcomes. Reliable tools that integrate key pathophysiological processes for early risk stratification remain limited. This study aimed to develop and internally validate a coupled inflammation-metabolism coupling index (IMCI) for early prediction of organ dysfunction progression within 24 h after intensive care unit (ICU) admission in patients with septic shock. METHODS: In this single-center retrospective observational study, 210 adult patients with septic shock admitted to the ICU between January 2020 and June 2025 were included. Organ dysfunction progression was defined as an increase in Sequential Organ Failure Assessment (SOFA) score ≥ 2 within 24 h. Baseline demographic characteristics, laboratory indicators, disease severity scores, and treatment-related variables, including white blood cell count, platelet count, Acute Physiology and Chronic Health Evaluation II (APACHE II) score, vasopressor dose, continuous renal replacement therapy, mechanical ventilation, and glucocorticoid administration, were collected and compared between groups. IMCI-A was constructed as ln(IL-6) × ln(lactate), and an extended index (IMCI-B) was evaluated in sensitivity analyses. Logistic regression, receiver operating characteristic analysis, calibration curves, bootstrap validation, and decision curve analysis were performed to assess association, predictive performance, and clinical utility. RESULTS: Organ dysfunction progression occurred in 88 patients (41.9%). Patients with organ dysfunction progression had a higher inflammatory and metabolic burden and more severe baseline illness than those without progression. In the fully adjusted model incorporating demographic variables, baseline SOFA score, laboratory indicators, disease severity, and treatment-related variables, IMCI-A remained independently associated with 24-h organ dysfunction progression (adjusted OR = 1.68, 95% CI: 1.18-2.39; p = 0.004). IMCI-A demonstrated excellent discriminative performance (area under the curve [AUC] = 0.929), which further improved when combined with SOFA (AUC = 0.948). Calibration and decision curve analyses showed good agreement and favorable net clinical benefit. CONCLUSIONS: IMCI provides a robust and clinically meaningful tool for early prediction of organ dysfunction progression in septic shock, offering incremental value beyond conventional organ function assessment.