Hyperbilirubinemia in infants with Gram-negative sepsis does not affect mortality.

BACKGROUND: Sepsis is associated with an increased production of oxidant species and a decrease in endogenous antioxidant defenses. Mortality is high, especially when endotoxins are involved, e.g., in infants with Gram-negative sepsis. Yet, chronic as well as acute unconjugated hyperbilirubinemia has been shown to protect against endotoxin-induced shock in vivo in rats and in mice. We hypothesized that hyperbilirubinemia in infants with Gram-negative sepsis improves survival and/or mitigates the inflammatory response. OBJECTIVE: To assess the relationships between serum bilirubin concentrations on the one hand, and leukocyte count, C-reactive protein and survival on the other hand, in infants with Gram-negative sepsis. METHODS: Retrospectively, we retrieved clinical and biochemical data from infants less than 90 days of age with a blood culture-proven Gram-negative sepsis between January 1998 and December 2005. RESULTS: We identified 92 infants with Gram-negative sepsis in the indicated period. Median gestational age was 29 (24-42) weeks. 22 Patients died. Preceding sepsis, median total serum bilirubin concentrations were below 150 µmol/L. Median concentrations of conjugated bilirubin concentrations increased (+63%, p<0.05), and median concentrations of unconjugated bilirubin decreased (-36%, p<0.05) in infants with Gram-negative sepsis. Median total bilirubin concentrations before and during sepsis were not significantly different between survivors and non-survivors. Changes in bilirubin concentrations were not significantly correlated with changes in either white blood cell count or C-reactive protein. CONCLUSION: Present data do not support the concept that bilirubin positively affects survival or the inflammatory response in infants with Gram-negative sepsis.