Procalcitonin is persistently increased among children with poor outcome from bacterial sepsis*

Abstract
Objective To examine the relationships between procalcitonin, bacterial infection, sepsis-induced multiple organ failure, and mortality rate in children. Design Cohort study. Setting A multidisciplinary, tertiary-care pediatric intensive care unit. Patients Seventy-eight children meeting criteria for sepsis or septic shock and 12 critically ill children without sepsis. Interventions Venous or arterial blood sampling. Measurements and Main Results Demographic, epidemiologic, and outcome data were recorded. Plasma from children with sepsis were collected on days 1 and 3, and procalcitonin concentrations were measured by immunoluminometric assay. Organ failure index scores were determined, and multiple organ failure was defined as organ failure index ≥3. Persistent multiple organ failure was defined by presence of multiple organ failure on day 3. Procalcitonin concentrations (median [25th percentile-75th percentile]) were increased among children with sepsis on day 1 (2.4 ng/mL [0.2–24.2], p < .01) but not on day 3 (0.8 ng/mL [0.1–8.1], p = nonsignificant) vs. controls (0.2 ng/mL [0.1–0.5]). This increase in procalcitonin concentration was particularly robust among children with bacterial sepsis on day 1 (7.1 ng/mL [0.9–44.8], p < .001) and on day 3 (2.9 ng/mL [0.1–32.4], p < .05). Procalcitonin concentrations were not increased among children with fungal, viral, or culture-negative sepsis vs. controls. Procalcitonin concentrations were persistently increased over time among patients with bacterial sepsis who had persistent multiple organ failure (p < .05) and who died (p < .01) but not among patients with nonbacterial sepsis. Conclusions Procalcitonin is persistently increased among children with poor outcome from bacterial sepsis. Further study is needed to better delineate this differential procalcitonin response to bacterial vs. nonbacterial sepsis and to characterize any mechanistic role that procalcitonin might play in the development of bacterial sepsis-induced multiple organ failure and mortality.