1036

Abstract

Introduction: Procalcitonin (PCT) is a cytokine produced in response to endotoxin which increases in vitro within 4-12 hours of infection onset. PCT has shown promise as a highly sensitive biomarker of sepsis in certain adult populations; however, no large studies have been performed in critically ill children, a population in whom cytokine activation is likely due to underlying illnesses. Methods: A retrospective, observational study of serum PCT measurements over the two-year period from October 2010 to October 2012 was conducted. PICU patients (0-21 years of age) with one or more febrile episodes while not receiving antibiotics were included in the analysis. For each episode of fever, the following data were collected: serum PCT, white blood cell count, C-reactive protein, Pediatric Risk of Mortality (PRISM) and Pediatric Logistic Organ Dysfunction (PELOD) scores, oxygenation index, vasoactive medications, bacterial culture results, viral assay results, antibiotic choice and course. Results: From a total of 1260 PCT values, 111 met inclusion criteria and were analyzed. Fifty-two percent of the study cohort was male; subject age ranged from 1 month to 19 years with a mean of 6.5 years. A Receiver Operator Curve (ROC) was used to identify the optimal cut-off for PCT to predict a positive blood culture. The area under the ROC curve was 0.74 [95% CI (0.6-0.87]. A PCT cut-off value of 0.35 ng/mL demonstrated 100% sensitivity, and 40% specificity. Conclusions: While our data do not show PCT to be the ideal test to predict bacteremia, its negative predictive value can allow physicians to stop antibiotic treatment, or even withhold it, if the value is sufficiently low. The decreased use of antibiotics can, in turn, decrease side effects, reduce antibiotic resistance and curb alterations in the microbiome.