Can Lactate Clearance Predict Mortality in Critically Ill Children?

Area of Science:

• Pediatric Critical Care Medicine
• Biomarkers in Critical Illness
• Lactate Kinetics

Background:

• Single blood lactate measurements have limited prognostic value in critically ill children.
• Serial lactate monitoring, particularly lactate clearance, may offer superior predictive capabilities.

Purpose of the Study:

• To assess the efficacy of 6-hour lactate clearance post-PICU admission as a mortality predictor in critically ill children.
• To compare the prognostic significance of initial lactate levels versus 6-hour lactate clearance.

Main Methods:

• A prospective observational study involving 76 critically ill children in a pediatric intensive care unit (PICU).
• Arterial blood lactate levels were measured at admission and 6 hours later.
• Lactate clearance was calculated, and patients were stratified into groups based on clearance (positive vs. non-positive).
• Statistical analyses included ROC curves, Kaplan-Meier survival analysis, and multivariate logistic regression.

Main Results:

• Initial lactate levels were a poor predictor of mortality (AUC = 0.519).
• Lactate clearance after 6 hours significantly predicted mortality (AUC = 0.766, p < 0.001).
• Patients with positive lactate clearance demonstrated significantly better survival (p < 0.001).
• Both 6-hour lactate clearance (OR = 0.98) and the Pediatric Index of Mortality 2 (PIM2) score (OR = 4.7) were independent predictors of mortality.

Conclusions:

• Lactate clearance after 6 hours of PICU admission is a valuable and independent predictor of mortality in critically ill children.
• Serial lactate assessment offers greater prognostic insight than single measurements in this population.