Epidemiology of sepsis and multiple organ dysfunction syndrome in children

STUDY OBJECTIVES: To determine the cumulated incidence and the density of incidence of systemic inflammatory response syndrome (SIRS), sepsis, severe sepsis, septic shock, and multiple organ dysfunction syndrome (MODS) in critically ill children; to distinguish patients with primary from those with secondary MODS. DESIGN: Prospective cohort study. SETTING: Pediatric ICU of a university hospital. PATIENTS: One thousand fifty-eight consecutive hospital admissions. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: SIRS occurred in 82% (n=869) of hospital admissions, 23% (n=245) had sepsis, 4% (n=46) had severe sepsis, 2% (n=25) had septic shock; 16% (n=168) had primary MODS and 2% (n=23) had secondary MODS; 6% (n=68) of the study population died. The pediatric risk of mortality (PRISM) scores on the first day of admission to pediatric ICU were as follows: 3.9 +/- 3.6 (no SIRS), 7.0 +/- 7.0 (SIRS), 9.5 +/- 8.3 (sepsis), 8.8 +/- 7.8 (severe sepsis), 21.8 +/- 15.8 (septic shock); differences among groups (p=0.0001), all orthogonal comparisons, were significant (p<0.05), except for patients with severe sepsis. The observed mortality for the whole study population was also different according to the underlying diagnostic category (p=0.0001; p<0.05 for patients with SIRS and those with septic shock, compared with all groups). Among, patients with MODS, the difference in mortality between groups did not reach significance (p=0.057). Children with secondary MODS had a longer duration of organ dysfunction (p<0.0001), a longer stay in pediatric ICU after MODS diagnosis (p<0.0001), and a higher risk of mortality (odds ratio, 6.5 [2.7 to 15.9], p<0.0001) than patients with primary MODS. CONCLUSIONS: SIRS and sepsis occur frequently in critically ill children. The presence of SIRS, sepsis, or septic shock is associated with a distinct risk of mortality among critically ill children admitted to the pediatric ICU; more data are needed concerning children with MODS. Secondary MODS is much less common than primary MODS, but it is associated with an increased morbidity and mortality; we speculate that distinct pathophysiologic mechanisms are involved in these two conditions.