Plasma nitrite/nitrate and endothelin-1 concentrations in neonatal sepsis

Aim: To determine the changes in plasma nitrite/nitrate (NOx) and endothelin-1 (ET-1) concentrations during neonatal sepsis. Methods: In a prospective study, 60 consecutive newborns meeting the criteria for sepsis and without receiving exogenous nitric oxide (25 haemoculture-positive [HC+] and 35 haemoculture-negative [HC-]) were compared with 68 healthy newborns (46 full-term and 22 preterm). NOx and ET-1 concentrations were measured in each newborn within 48 h of diagnosis of sepsis and then every third day up to three determinations. SNAP-II and SNAPPE-II severity scores were performed at the moment of highest clinical severity. Results: At the beginning of the sepsis period, controls and septicaemic newborns had similar NOx and ET-1 levels, with the exception of infants with severe HC+ sepsis. Throughout the sepsis period, NOx increased in moderate HC+ sepsis and decreased in HC- sepsis, reaching a significant difference at the end of the study period (59.9 ± 72.7 vs 33.9 ± 15.3 μmol/L; p = 0.036). Meanwhile, ET-1 in newborns with severe HC+ sepsis remained higher than that in the moderate HC+ sepsis group and HC- group, reaching significant differences in all the periods. The highest ET-1 value was positively correlated with SNAP-II and SNAPPE-II scores.

Conclusion: NOx concentrations increased throughout the neonatal HC+ sepsis period, reaching significant differences after 7-9 d. The highest ET-1 levels in neonatal HC+ sepsis emerged before the NOx peak, at 3-5 d, and later decreased. Only newborns with severe HC+ sepsis presented a significant increase in ET-1 concentrations from the beginning of the septicaemic process.