The accuracy of serum lactate in mortality prediction in sepsis patients: A systematic review and meta-analysis.

Objective: Our study aims to assess the accuracy of serum lactate (SL) in mortality prediction among sepsis patients.

Methods: PubMed, Embase, Cochrane Library, and Web of Science were searched until March 27, 2025. The quality of cohort and case-control studies was rated via the Newcastle-Ottawa Scale (NOS), and that of cross-sectional ones was assessed per the Agency for Healthcare Research and Quality (AHRQ) criteria. Our meta-analysis was completed using Stata 15.

Results: 34 studies involving 46,300 sepsis patients were included. Pooled analyses demonstrated that elevated SL was significantly associated with rising mortality in sepsis patients (when effect size (ES) was reported as hazard ratio (HR): HR = 1.85, 95% CI: 1.29-2.66, p < 0.05; when ES was reported as odds ratio (OR): OR = 1.52, 95% CI: 1.39-1.67, p < 0.001). 17 studies evaluated the performance of SL for mortality prediction in sepsis patients, revealing the pooled sensitivity, specificity, and an area under the curve (AUC) of 0.80 (95% CI: 0.75-0.85), 0.37 (95% CI: 0.25-0.51), and 0.73 (95% CI: 0.68-0.76).

Conclusions: Elevated SL is closely associated with mortality in sepsis patients, particularly when the threshold is ≥4 mmol/L. Nevertheless, its diagnostic value remains limited. Future research should address the standardization of lactate measurement procedures and the development of multimodal prediction models for a transformation and breakthrough from risk stratification to precise intervention.