Different acute-phase response in newborns and infants undergoing surgery.

In a prospective clinical study, we investigated the inflammatory response in 88 neonatal subjects (43 boys and 45 girls) who underwent major abdominal surgery owing to congenital malformation involving the gastrointestinal tract and compared it with the response in 20 infants (8 boys, 12 girls; mean age, 4 mo) who underwent elective surgery for resolution of an existing temporary stoma. In both groups, plasma levels of endotoxin, IL-6, and C-reactive protein as well as leukocyte counts were determined during and after surgery. Endotoxin was measured by the Limulus amebocyte test, IL-6 by ELISA, and C-reactive protein by nephelometry. Statistical analyses were performed using the Wilcoxon signed-rank test. A significant increase in circulating endotoxin and a leukocyte shift was observed in the infant group only. Postoperatively, IL-6 levels peaked between 2 and 6 h and C-reactive protein after 24 h in the infant group. In contrast, no significant increase in the levels of endotoxin, IL-6, and C-reactive protein in plasma were observed during and after surgery in the neonatal subjects, except those with gastroschisis. Newborns with gastroschisis developed an inflammatory response after surgery that was less pronounced than the response of infants older than 4 mo. The finding that endotoxemia in newborns does not follow surgical trauma is most likely because of the absence of bacterial colonization of the gastrointestinal tract.