Cumulative influence of organ dysfunctions and septic state on mortality of critically ill children.

The interaction between sepsis and multiple organ dysfunction syndrome is poorly defined in children. We analyzed by Cox regression models the cumulative influence of organ dysfunctions, using the pediatric logistic organ dysfunction (PELOD) score, and septic state (systemic inflammatory response syndrome or sepsis, severe sepsis, and septic shock) on mortality of critically ill children. We included 593 children (mortality rate: 8.6%) from three pediatric intensive care units; 514 patients had at least a systemic inflammatory response syndrome and 269 had two or more organ dysfunctions. Hazard ratio of death significantly increased with the severity of organ dysfunction, as estimated by the PELOD score, and the worst diagnostic category of septic state. Each increase of one unit in the PELOD score multiplied the hazard ratio by 1.096 (p < 0.0001); hazard ratio of diagnostic category was 9.039 (p = 0.031) for systemic inflammatory response syndrome or sepsis, 18.797 (p = 0.007) for severe sepsis and 32.572 (p < 0.001) for septic shock. Cumulative hazard ratio of death = (hazard ratio of PELOD score) x (hazard ratio of diagnostic category). We conclude that there is a cumulative accrual of the risk of death both with an increasing severity of organ dysfunction and an increasing severity of the diagnostic category of septic state.