Procalcitonin and cytokine levels: Relationship to organ failure and mortality in pediatric septic shock

Background: Procalcitonin (PGT), a marker of bacterial sepsis, may also act as a mediator of the inflammatory response to infection, and thus influenc e outcome. Objective: To investigate the relationship between PCT, interleukin (IL)-10 , tumor necrosis factor (TNF), organ failure, and mortality in pediatric se ptic shock. Design: Prospective observational study, Setting.. A 16-bed pediatric intensive care unit of a university hospital. Patients: A total of 75 children with septic shock having a median age of 4 3.1 months (range, 0.1-192 months). Children who had received antibiotics f or >24 hrs were excluded. A total of 37 patients (49%) had meningococcal di sease, and 72 patients (96%) required mechanical ventilation. Interventions: The pediatric risk of mortality (PRISM) score, multiple orga n system failure (MOSF) score, duration of ventilation, length of ICU stay, and outcome were recorded. PCT, IL-10, and TNF were measured at admission to the intensive care unit. Sequential PCT levels were available at 0 hrs a nd 24 hrs in 39 patients (52%). Results: Observed mortality was 21/75 (28%). Data are median (range). The a dmission PCT (p = .0002) and TNF levels (p =.0001) were higher in children with higher MOSF scores. in survivors and nonsurvivors, the admission PCT w as 82 ng/mL vs. 273 ng/mL (p = .03), IL-10 was 62 pg/mL vs. 534 pg/mL (p =, 03), and TNF was 76 pg/mL vs. 480 pg/mL (p = .001), respectively. Area unde r the mortality receiver operating characteristic curve was 0.73 for PCT, 0 .67 for IL-10, and 0.76 for TNF, compared with 0.83 for the PRISM score. Of 39 children, 16 (41%) with sequential PCT measurements showed no fall in PCT after 24 hrs treatment. These children had higher admission levels of IL-10 (p = .03), and TNF (p =.03) compared with children who demonstrated a subsequent fall in PCT. Although the former did not have a higher median P RISM (p = .28) or MOSF score (p = .19), observed mortality was 44% (7 of 16 ) compared with 9% (2 of 23) (p = .02). Conclusion: The admission PCT, like TNF and IL-10, is related to the severi ty of organ failure and mortality in children with septic shock. A fall in PCT after 24 hrs of treatment may have favorable prognostic significance.