Clinical History.—A 2,290 g, 35-week preterm infant girl was transferred to Rainbow Babies and Children's Hospital, Cleveland, at 3 hours of age because of respiratory distress. The 30-year-old mother was gravida 3, para 1, abortus 1. Her pregnancy was uncomplicated until 35 weeks when a cesarean section was performed because of premature onset of labor complicated by breech presentation.
On admission, the infant was cyanotic in 60% oxygen. Examination of the chest showed an increased anteroposterior diameter, decreased chest excursion, intercostal retractions, and grunting respirations. The lungs were clear to auscultation. Examination of the heart was normal. The abdomen was soft with no distension, hepatosplenomegaly, or tenderness. The arterial blood gases in 65% fractional inspiratory oxygen (FIO2) were a pH of 7.26, Pco2 was 40 mm Hg, and Po2 was 123 mm Hg. The initial chest roentgenogram is shown in Fig 1.
After obtaining cultures, antibiotics