High endothelin-1 in the airways of preterm infants is associated with less severe respiratory distress during the early postnatal period.

OBJECTIVE: To study the relationship between endothelin-1 (ET-1) in the airways and respiratory distress in preterm infants.
METHODS: ET-1 was determined in 60 tracheal aspirates from 11 preterm intubated infants (gestational age 28.0 +/- 2.5 weeks) during the first week of life.
RESULTS: The concentration of ET-1 of the aspirates was 6 to 2760 pg/mL (median 293 pg/mL). Negative correlations existed between mean log ET-1 and mean airway pressure (R2 = .812) and fraction of inspired oxygen (R2 = .591), whereas a positive correlation was found between the arteriolar/alveolar oxygenation ratio within 3 hours of birth and mean log ET-1 on the first day (R2 = .555).
CONCLUSION: The association of high ET-1 in the airways with less severe respiratory distress in the early postnatal period may be attributable to effects of ET-1 on surfactant secretion or development of airway epithelium.