Early Lactate Clearance vs. Initial Lactate Levels: Which Predicts Mortality Better? A Systematic Review

Abstract

Background: Sepsis is a life-threatening condition that requires rapid diagnosis and intervention. Lactate levels have long been used as a marker of sepsis severity, with elevated initial lactate levels indicating poor prognosis. However, early lactate clearance—defined as the reduction of lactate levels within hours of resuscitation—has gained attention as a potential stronger predictor of patient outcomes, including mortality. This systematic review compares the predictive value of early lactate clearance and initial lactate levels in predicting mortality in septic patients.

Objective: To evaluate and compare the predictive capacity of early lactate clearance versus initial lactate levels for mortality in septic patients.

Methods: A comprehensive search of peer-reviewed studies published between 2010 and 2025 was conducted across databases including PubMed, Scopus, and Google Scholar. Studies were included if they assessed either early lactate clearance or initial lactate levels in septic patients and reported mortality outcomes. The quality of the studies was assessed using the Newcastle-Ottawa Scale for cohort studies and the Cochrane Risk of Bias tool for randomized controlled trials. Data were synthesized qualitatively and, where applicable, meta-analysis was conducted.

Results: Five studies met the inclusion criteria, including cohort and randomized controlled studies. All studies demonstrated that both initial lactate levels and early lactate clearance were significant predictors of mortality. However, early lactate clearance consistently provided a stronger and more reliable prediction of patient outcomes, particularly for those with high initial lactate levels. Patients who failed to clear lactate within the first 6 to 12 hours of resuscitation had significantly higher mortality rates. Meta-analysis showed that early lactate clearance was associated with improved survival rates and decreased incidence of multi-organ failure (p<0.05).

Conclusion: Early lactate clearance appears to be a more accurate and dynamic predictor of mortality in septic patients compared to initial lactate levels. The results of this review support integrating early lactate clearance into clinical practice for better prognosis assessment and management in sepsis. Further research is needed to standardize measurement protocols and confirm its utility across different patient populations.