CME Review ArticleProcalcitonin as a Marker of Severe Bacterial Infection in Children in the Emergency DepartmentDeis, Jamie N. MD*; Creech, Clarence B. MD, MPH†; Estrada, Cristina M. MD‡; Abramo, Thomas J. MD‡Author Information *Assistant Professor of Emergency Medicine, Wake Forest University Baptist Medical Center, Winston-Salem, NC (Deis); †Assistant Professor of Pediatric Infectious Disease (Creech), Vanderbilt Vaccine Research Program, Division of Pediatric Infectious Disease, Department of Pediatrics, ‡Assistant Professor of Emergency Medicine and Pediatrics, Associate Fellowship Director of the Pediatric Emergency Medicine Fellowship, Assistant Residency Director of the Emergency Medicine Residency Program (Estrada), Professor of Emergency Medicine and Pediatrics, Medical Director of the Pediatric Emergency Department, and Medical Director of Pediatric Transport, Pediatric Emergency Physician-in-Chief (Abramo), Department of Emergency Medicine, Monroe Carell Jr Children's Hospital at Vanderbilt, Nashville, TN. Reprints: Jamie N. Deis, MD, 703 Oxford House, Nashville, TN 37232-4700 (e-mail: firstname.lastname@example.org). Unless otherwise noted below, each faculty's spouse/life partner (if any) has nothing to disclose. The authors have disclosed that they have no significant relationship with or financial interests in any commercial companies that pertain to this educational activity. All staff in a position to control the content of this CME activity have disclosed that they have no financial relationships with, or financial interests in, any commercial companies pertaining to this educational activity. Lippincott CME Institute, has identified and resolved all faculty conflicts of interest regarding this educational activity. Pediatric Emergency Care: January 2010 - Volume 26 - Issue 1 - p 51-60 doi: 10.1097/PEC.0b013e3181c399df Buy Metrics Abstract Procalcitonin, the prohormone of calcitonin, is a relatively new and innovative marker of bacterial infection that has multiple potential applications in the pediatric emergency department. In healthy individuals, circulating levels of procalcitonin are generally very low (<0.05 ng/mL), but in the setting of severe bacterial infection and sepsis, levels can increase by hundreds to thousands of fold within 4 to 6 hours. Although the exact physiologic function of procalcitonin has not been determined, the consistent response and rapid rise of this protein in the setting of severe bacterial infection make procalcitonin a very useful biomarker for invasive bacterial disease. In Europe, serum procalcitonin measurements are frequently used in the diagnosis and the management of patients in a variety of clinical settings. To date, the use of procalcitonin has been limited in the United States, but this valuable biomarker has many potential applications in both the pediatric emergency department and the intensive care unit. The intent of this article is to review the history of procalcitonin, describe the kinetics of the molecule in response to bacterial infection, describe the laboratory methods available for measuring procalcitonin, examine the main causes of procalcitonin elevation, and evaluate the potential applications of procalcitonin measurements in pediatric patients. © 2010 Lippincott Williams & Wilkins, Inc.