Plasma Endothelin-1 Levels in Preterm Neonatal Infants with Acute Respiratory Failure

Abstract

Increased pulmonary vascular resistance in preterm infants is associated with acute respiratory failure (ARF) and at the same time endothelin-1 (E-1) plays an important role in neonatal pulmonary vascular responsiveness. Methods. Endothelin-1 levels were measured in two blood samples in 12 preterm infants with ARF and in 12 controls (at 32.2±1.3 and 29.8±1.2 weeks of gestation, respectively) by enzyme immunoassay. For this, the first and second blood samples were taken at 18 to 40 hours after birth. Results. The plasma level of E-1 in the first sample did not differ between the neonates of both groups. In the second sample, significantly higher E-1 concentrations were observed in the newborns with ARF than in the controls. In the first sample, E-1 concentration were higher than in the second one in both groups (p<0.001). There was a significant positive correlation between the second E-1 sample and the SNAPPE 2 scale rating (r=0.38; p=0.02). The plasma level of E-1 in the first sample did not differ in both groups (11.9 and 12.2 pg/ml, respectively). Conclusion. Neonates with and without ARF had the similar plasma E-1 levels in the first sample, by taking into account the fact that the E-1 levels were higher in ARF than in the controls at 18 to 40 hour after birth. Increased vascular resistance in ARF may be associated with the high level of E-1. Key words: endothe-lin-1, acute respiratory failure.