A Retrospective Study on the Availability of Arterial Lactate Levels as a Biomarker of Mortality in Critically Ill Children

Objective: We aimed to determine the threshold value of lactate levels, and to analyze its avaliability as mortality biomarker by correlating it with scoring systems in pediatric intensive care unit (PICU). Material and Methods: Observational retrospective cohort study. Our study was conducted among patients admitted to the 24-bed tertiary PICU of our hospital in 2015. All children between the ages of 1 month and 18 years were evaluated. Among 433 patients whose arterial blood gases were obtained during hospitalization, a total of 382 were included in the study. Patients with congenital metabolic disease with lactic acidosis were excluded. The arterial blood lactate levels on admission, PIM-2, PRISM-III and PELOD scores and survival status of the patients were evaluated. Correlation between lactate levels and mortality scores, threshold values of lactate levels and the factors affecting mortality risk were the main variable of interest. Results: There was a significant correlation between lactate levels and scores in patients who died (p<0.001). Receiver operating characteristic (ROC) curve analysis showed that blood lactate level was an effective parameter on mortality (area under the curve=AUC: 0.861; p<0.001) with a cut-off value of 2.55 mmol/L. The mortality risk was 1.38 fold higher in patients with higher levels of lactate. Conclusion: In our series, the levels of lactate were higher in critically ill children who died. Again, lactate levels and mortality scores of these children were correlated. In our series, the levels of lactate were higher in critically ill children who died. Again, lactate levels and mortality scores of these children were correlated. We were able to establish a cut-off point with high specificity for predicting evolution. These findings should be validated in prospective and multicenter studies for their incorporation into scoring systems.