The Diagnostic Accuracy of Serum Procalcitonin for Bacteremia in Critically Ill Children

Infect Dis Clin Pract (Baltim Md). 2016 Nov;24(6):343-347. doi: 10.1097/IPC.0000000000000432.


Background: Bacterial sepsis is frequently encountered in children admitted to the Pediatric Intensive Care Unit (PICU) and requires early recognition and treatment. Procalcitonin (PCT) is a serum biomarker with a high sensitivity to predict bacteremia in critically-ill adults. This study sought to evaluate the diagnostic accuracy of PCT for bacteremia in febrile children in the PICU.

Methods: This retrospective observational study used data from children admitted to the PICU from October 2010 to October 2012. Patients up to 21 years of age were included if they had an abnormal temperature, serum PCT and blood culture assayed, and were not receiving empiric antibiotics at the time.

Results: There were 202 PCT values that met inclusion criteria. The prevalence of positive blood cultures was 13.2% (27 total positive blood cultures). The area under the curve (AUC) for PCT was 0.79 (95% CI, 0.70-0.89), the AUC for lactate was 0.76 (95% CI, 0.65-0.87), and the AUC for C-reactive protein was 0.68 (95% CI, 0.57-0.80). The optimal threshold of PCT for accuracy was determined to be 2 ng/mL (sensitivity = 69.2%, specificity = 74.4%, positive predictive value = 28.6%, negative predictive value = 94.2%). The combination of an abnormal lactate (> 2.0mmol/L) increased the specificity of PCT for diagnosing bacteremia.

Conclusions: PCT has a good diagnostic accuracy to rule-out bacteremia in critically-ill, febrile children. The combination of PCT and an abnormal lactate value increases the specificity and may improve the ability to diagnose bacteremia.

Keywords: bacteremia; critical illness; pediatrics; procalcitonin.