503 Plasma Endothelin-1 Levels in Preterm Newborns with Congenital Pneumonia

Abstract

Objective: Increased pulmonary vascular resistance in preterm newborn infants with congenital pneumonia is suggested, and endothelin-1 plays an important role in pulmonary vascular reactivity in newborns. Methods: We determined plasma (second sample) levels of endothelin-1 in 12 preterm newborns with congenital pneumonia and 15 without congenital pneumonia (gestational ages: 28,20 ± 1,22 and 28,01 ± 1,12 weeks, respectively). Blood and a second blood sample taken 18 to 40 h after birth were used for endothelin-1 determination by enzyme immunoassay. Result: Plasma levers ET-1 concentrations were higher than second sample ET-1 levels in both groups (P < 0.001). There was a significant positive correlation between second sample ET-1 and SNAPPE II (r = 0.32, P = 0.01). There were no correlations between plasma ET-1 levels first sample and second sample ET-1 concentrations and 5-min Apgar score < 5. Duration of mechanical ventilation had a significant positive correlation with second sample ET-1 (r = 0.478, P = 0.02). Plasma lever ET-1 levels did not differ between control and congenital pneumonia (10.02 and 14.20 pg/mL, respectively, P = 0.90). Second sample ET-1 levels had significantly higher ET-1 levels than controls (1.88 and 3.82 pg/mL, respectively, P = 0.001) Conclusion: Our newborn infants with and without congenital pneumonia had similar plasma ET-1 levels, whereas ET-1 levels were higher in congenital pneumonia than in control newborns 18 to 40 h after birth. The increased vascular resistance in congenital pneumonia may be related to high ET-1 levels.