Optimizing Management of Febrile Young Infants Without Serum Procalcitonin

Authors

Brett Burstein, Montreal Children's Hospital, Division of Pediatric Emergency Medicine, McGill University Health Centre, and the Department of Biostatistics, Epidemiology and Occupational Health, McGill University, Montreal, Quebec, Canada.
Caroline Wolek, McGill University, Montreal, Quebec, Canada.
Cassandra Poirier, Department of Anesthesiology, Pharmacology & Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada.
Alexandra Yannopoulos, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.
T Charles Casper, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah.
Mohammed Kaouache, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.
Nathan Kuppermann, Departments of Pediatrics and Emergency Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC.

Document Type

Journal Article

Publication Date

2-1-2025

Journal

Pediatrics

Volume

155

Issue

2

DOI

10.1542/peds.2024-068200

Abstract

BACKGROUND: Febrile young infants are at risk of invasive bacterial infections (IBIs; bacteremia or bacterial meningitis). American Academy of Pediatrics (AAP) guidelines recommend that when procalcitonin testing is unavailable, C-reactive protein (CRP), absolute neutrophil count (ANC) and temperature should be used to identify low-risk infants. We sought to determine the optimal combination of these inflammatory markers to predict IBI when procalcitonin is unavailable. METHODS: This was a secondary analysis of prospectively collected data for all febrile infants aged 60 days or younger evaluated at a tertiary pediatric emergency department (January 2018 to July 2023). Previously healthy term infants aged 8 to 60 days with rectal temperatures of 38.0°C or greater meeting AAP inclusion/exclusion criteria were analyzed. A decision rule was derived by classification and regression tree analysis with 10-fold cross-validation then compared to AAP-recommended thresholds of ANC ≤ 5200/mm3, CRP ≤ 20 mg/L, and temperature ≤ 38.5°C. RESULTS: Among 1987 infants, 38 (1.9%) had IBIs. The AAP-recommended thresholds missed no IBIs (sensitivity: 100.0% [95% CI, 88.6%-100.0%]; negative predictive value (NPV): 100.0% [95% CI, 99.5%-100.0%]; specificity: 50.7% [95% CI, 48.5%-53.0%]). Optimal derived thresholds were CRP ≤ 22.2mg/L, temperature ≤ 39.0°C, and ANC ≤ 4500/mm3; urinalysis and age were not selected. The derived rule also missed no IBIs (sensitivity: 100.0% [95% CI, 88.6%-100.0%]; NPV: 100.0% [95% CI, 99.7%-100.0%]); however, specificity improved to 83.8% (95% CI, 82.1%-85.4%). Area under the receiver operating curve for the cross-validated rule (91.9% [95% CI, 91.1%-92.7%]) was higher than at AAP-recommended thresholds (75.4% (95% CI, 74.3%-76.5%]). CONCLUSIONS: The combination of ANC, CRP, and temperature at statistically derived thresholds improved diagnostic accuracy for identifying infants at low risk of IBIs compared to AAP-recommended thresholds.

APA Citation

Burstein, Brett; Wolek, Caroline; Poirier, Cassandra; Yannopoulos, Alexandra; Charles Casper, T; Kaouache, Mohammed; and Kuppermann, Nathan, "Optimizing Management of Febrile Young Infants Without Serum Procalcitonin" (2025). GW Authored Works. Paper 6680.
https://hsrc.himmelfarb.gwu.edu/gwhpubs/6680

Department

Pediatrics