Plasma lactate can improve the accuracy of the Pediatric Sequential Organ Failure Assessment Score for prediction of mortality in critically ill children: A pilot study

Abstract

BackgroundPlasma lactate has been used to predict the prognosis of critically ill children, but mortality risk scores appear to be more appealing, particularly in resource-limited countries. ObjectiveTo assess the prognostic utility of lactate compared with the pediatric Sequential Organ Failure Assessment (pSOFA) score among the general pediatric intensive care unit (PICU) population. MethodsThis was a prospective observational study including 78 children admitted to a tertiary-level PICU. Plasma lactate was measured upon admission and repeated 24h later. pSOFA score, Pediatric Risk of Mortality, and Pediatric Index of Mortality-2 (PIM2) were calculated. The primary outcome was 30-day mortality. ResultsIn total, 47.4% of patients had hyperlactatemia at admission. Among these, 20.5% had persistent hyperlactatemia. No significant difference in admission lactate level was found between survivors and nonsurvivors. The 24-h, peak, and average lactate levels were higher among nonsurvivors (P=0.005, 0.035, and 0.019, respectively). The 24-h lactate level and pSOFA score were independent predictors of mortality (adjusted odds ratio and 95% confidence interval=1.12 [1.02–1.23] and 1.80 [1.23–2.64], respectively]. The 24-h lactate level showed positive correlations with pSOFA, PRISM, and PIM2 (Spearman correlation coefficient=0.31, 0.23, 0.43; P=0.006, P=0.047, P<0.001, respectively). The 24-h lactate level had an area under the receiver operating characteristic curve (AUC) of 0.77 (P=0.013) for mortality prediction, while admission, peak, and average lactate level had an AUC of 0.69, 0.69, 0.71 (P=0.086, P=0.035, P=0.019), respectively. PIM2, PRISM, and pSOFA score had an AUC of 0.80, 0.78, 0.82 (P=0.001, P=0.001, and P<0.001), respectively. Combining 24-h lactate level with pSOFA demonstrated superior performance (AUC=0.88). ConclusionBoth 24-h lactate level and pSOAF are useful for prediction of mortality. Incorporating the 24-h lactate level into the pSOFA Score achieved superior prognostic utility.