Terbutaline does not improve lung function in preterm rabbits

Abstract

We used the premature rabbit model of surfactant deficiency to test the hypothesis that perinatal administration of terbutaline would lead to increased secretion of surfactant into the alveolar space and increase lung compliance during mechanical ventilation. Fetuses underwent delivery at a gestational age of 28 days (term 31 days) followed by mechanical ventilation. Fetuses were subdivided into four treatment protocols: control, fetuses given terbutaline at birth, fetuses of mothers given terbutaline 1 hour before delivery, and fetuses of mothers given terbutaline intramuscularly 12 hours before delivery. Dynamic compliance was determined. After this, alveolar lavage fluid was obtained for phosphatidylcholine content determination. Some fetuses were killed at birth and their alveolar lavage phosphatidylcholine was determined. Among the fetuses undergoing mechanical ventilation, perinatal terbutaline exposure did not alter either dynamic compliance or alveolar lavage phosphatidylcholine. Mechanical ventilation was associated with large increases in alveolar lavage phosphatidylcholine content. Perinatal beta-adrenergic agonist exposure does not alter in vivo lung function following preterm delivery.