Betamethasone increases pulmonary compliance in part by surfactant-independent mechanisms in preterm XXXX .

@entity95 @entity2434 @entity2507 @entity230 @entity288
Antenatal exposure to @entity288 is known to increase the pulmonary compliance of preterm animals. We wished to determine whether this was due solely to alteration in lung surfactant content. @entity95 does were injected with either vehicle alone or betamethasone on days 25 and 26 of gestation. Fetuses were delivered at 27 days and given either 50% lactated Ringer's or intratracheal natural surfactant prior to their first breath. Fetuses were mechanically ventilated at a tidal volume of 12 ml/kg for 60 min with periodic compliance measurements. Following ventilation an alveolar lavage was collected for @entity2434 determination. Some fetuses did not undergo ventilation but had saline compliance studies instead. Fetuses given intratracheal surfactant had a higher dynamic compliance than fetuses exposed to antenatal @entity288 (0.55 +/- 0.01 versus 0.48 +/- 0.02 ml/cm @entity2507 /kg, respectively). Fetuses exposed to antenatal @entity288 and given intratracheal surfactant had a dynamic compliance (0.66 +/- 0.02) that was greater than those exposed to either single therapy. This was found despite an alveolar surfactant content equal to that in fetuses receiving intratracheal surfactant alone. Saline compliance at birth was significantly greater for fetuses exposed antenatally to @entity230 . These data imply the existence of a nonsurfactant mechanism by which antenatal @entity288 increase fetal pulmonary compliance.
