Association of Procalcitonin Value and Bacterial Coinfections in Pediatric Patients With Viral Lower Respiratory Tract Infections Admitted to the Pediatric Intensive Care Unit.

OBJECTIVE: Our primary objective was to determine the utility of procalcitonin (PCT) in detection of bacterial coinfection in children < 5 years admitted to the pediatric intensive care unit with viral lower respiratory tract infection (LRTI).
METHODS: Electronic medical record review of children < 5 years admitted to the pediatric intensive care unit with a viral LRTI who also had at least 1 PCT concentration measurement.
RESULTS: Seventy-five patients were admitted to the intensive care unit and met the inclusion criteria for this investigation. The PCT threshold concentrations of 0.9, 1, 1.4, and 2 ng/mL were found to be statistically significant in determining the presence of a bacterial coinfection. The PCT concentration with the most utility was 1.4 ng/mL with sensitivity, specificity, positive and negative predictive values of 46%, 83%, 68%, and 76%, respectively. For patients with serial PCTs, the second PCT correctly influenced treatment decisions for 11 of 25 patients (44%).
CONCLUSIONS: A PCT value of 1.4 ng/mL determined the presence of a bacterial coinfection primarily owing to the high specificity and negative predictive value. Our data add evidence to the relatively high negative predictive value of PCT concentrations in identifying patients with bacterial coinfection, specifically in the case of viral LRTI. In addition, our preliminary data indicate serial PCT measurements may help further influence correct treatment decisions. Prospective, controlled studies are warranted to validate an appropriate PCT threshold concentration to help in identifying bacterial coinfection as well as to further explore the role of serial PCT values in determining the absence or presence of a bacterial coinfection.