Evaluation of the Association of Early Elevated Lactate With Outcomes in Children With Severe Sepsis or Septic Shock

Abstract

Objective: The aim of the study was to assess the association of initial lactate (L0) with mortality in children with severe sepsis.

Methods: This prospective cohort study included 74 patients younger than 18 years with severe sepsis admitted to the pediatric intensive care unit (PICU) of a tertiary, academic children's hospital with lactate measured within 3 hours of meeting severe sepsis or septic shock. The primary outcome was in-hospital mortality. The secondary outcomes included PICU and hospital length of stay.

Results: Although overall mortality was 10.5% (n = 18), patients with L0 measured (n = 72) had a higher mortality (16% vs 6%, P = 0.03) and higher median PRISM-III risk of mortality scores (P = 0.02) than those who did not. Median L0 was no different between nonsurvivors and survivors (3.6 mmol/L [interquartile range, 2.0-9.0] in nonsurvivors vs 2.3 mmol/L [interquartile range, 1.4-3.5] in survivors, P = 0.11). However, L0 was independently associated with PRISM-III score (coefficient, 1.12; 95% confidence interval, 0.4-1.8; P = 0.003) with an increase in mean PRISM-III score of 1.12 U for every 1 mmol/L increase in L0, with L0 accounting for 12% of the variability in PRISM-III scores between patients. There was no association between L0 and PICU or hospital length of stay.

Conclusions: Although our single center study did not demonstrate that an elevated early lactate is associated with mortality in pediatric severe sepsis, L0 did correlate strongly with PRISM-III, the most robust measure of mortality risk in pediatrics. Therefore, early lactate measurement may be important as an early biomarker of disease severity. These data should be validated in a larger, multicenter, prospective study.

Figure 1. Scatter Plot of Lactate levels measured at time of severe sepsis or septic shock diagnosis (L0) and PRISM-III Score

Initial lactate levels correlated with PRISM-III score, a severity of illness score well validated for mortality prediction in pediatric critical illness, rho 0.33, p<0.01