Relationship of Serum Procalcitonin, C-reactive Protein, and Lactic Acid to Organ Failure and Outcome in Critically Ill Pediatric Population

ontinuing high rates of morbidity and mortality in PICU due to infections dictate the need for biomarkers to determine the prognosis of critically ill children at admission. nventionally, diagnosis of sepsis was based on clinical signs and symptoms of sepsis, such as fever, tachycardia, and tachypnea, supported by cultures. More recently, sepsis biomarkers have been used. Currently, most commonly used biomarkers to identify sepsis and predict outcome are lactic acid and C-reactive protein (CRP). Lactic acid levels have been used as a biomarker for tissue hypoxia and anaerobic metabolism, and it is the most widely utilized sepsis biomarker indicating organ dysfunction. Investigators have reported that persistent hyperlactatemia serves as the predictor of poor outcome in critically ill children suffering from sepsis. owever, factors associated with sepsis such as liver failure or mitochondrial dysfunction may also cause false elevation of lactic acid. CRP is a marker of acute inflammatory response rather than of infection and is nonspecific. However, it may be useful in determining sepsis severity and its progression. RP has also been shown to have a poor predictor of mortality Objective: To evaluate the clinical and prognostic utility of procalcitonin (PCT), C-reactive protein (CRP), and lactic acid in children admitted to the Pediatric Intensive Care Unit (PICU) of a university teaching hospital. Materials and Methods: Medical records of children (1 month-16 years) tested for serum PCT at the time of admission in the PICU of our hospital from July 1, 2013, to January 15, 2015, were reviewed. Within 24 h of admission, the Pediatric Risk of Mortality Score, blood cultures, white blood cell count, neutrophil counts, serum CRP, plasma lactic acid, and PCT were noted. Patient outcome was assessed at hospital discharge, and the patients were divided into nonsurvivors and survivors. Results: A total of 167 children being admitted to the PICU were enrolled. The median age of the study population was 3 years (0-16 years), with 58.6% being males. Nonsurvivors had significantly higher lactic acid (4.7 mmol/L 2.07-7.6; P < 0.05) than that of the survivors (2 mmol/L 1.3-3; P < 0.05). In addition, nonsurvivors (94.4%; P < 0.05) had greater incidence of multiple organ dysfunction syndrome (MODS) than that of the survivors (38.05%; P < 0.05). Binary logistic regression showed age, MODS, and lactic acid to be associated with mortality. Conclusions: This study found that in comparison to PCT and CRP, high plasma lactic acid levels are associated with the development of all-cause MODS and worse outcome in critically ill children admitted in PICU. Prediction of prognosis based on the lactic acid alone may contribute to improve patient management, but further studies are required to endorse our findings.