Bile acid pneumonia: a "new" form of neonatal respiratory distress syndrome?

Abstract

We describe 3 cases of neonatal respiratory distress syndrome (RDS) in near-term infants, born from mothers with severe intrahepatic cholestasis of pregnancy. Common pictures of the cases were: good indices of lung maturity in the amniotic fluid; severe RDS requiring mechanical ventilation; high serum bile acid (BA) levels in the early days of life; no meconium aspiration; negative cultures; and absence of indirect laboratory signs of infection. After the first case, we hypothesized that abnormally high BA levels could have reversed the action of phospholipase A2 in the lungs, causing a degradation of phosphatidylcholines to lysophosphatidylcholines and the consequent lack of surfactant activity, leading to the severe respiratory distress. Consequently, in cases 2 and 3, we gave intratracheal surfactant to the infants, which, although administered around the first 24 hours of life, showed to be helpful. Our experience suggests that a high level of attention in the management of newborn infants (even near-term infants) born from women with intrahepatic cholestasis of pregnancy is necessary to detect as soon as possible signs and symptoms of this "unexpected" RDS, which can assume a very severe clinical picture. In such instances, we recommend that the diagnosis of BA pneumonia be kept in mind and that exogenous surfactant be given as soon as possible, even in the presence of indices of normal lung maturity in the amniotic fluid. Finding high levels of BA and lysophosphatidylcholines in the bronchoalveolar lavage of affected infants would aid in support of the diagnosis.