Lactate to creatinine ratio: just another biomarker?

Biomarkers that meaningfully influence outcomes in pediatric sepsis remain limited. Lactate is commonly used to assess illness severity but is constrained by developmental variability and sensitivity to transient physiologic stress. The lactate-to-creatinine ratio (LCR) has been proposed as a composite biomarker that integrates metabolic derangement with early organ dysfunction to improve risk stratification in critically ill children. Although biologically plausible and readily available, pediatric evidence for LCR is largely restricted to measurements obtained early in the intensive care unit course, raising questions about its clinical relevance in a dynamic disease process. In this commentary, we examine the rationale for LCR as a sepsis biomarker, critique the limitations of single time-point assessment, and consider whether LCR offers actionable information beyond existing clinical evaluation and established biomarkers. We argue that the clinical value of LCR will depend on its ability to inform decision-making and improve patient-centered outcomes, rather than prognostic association alone.