A 2000-gram male infant was delivered at 34 weeks’ gestational
age by cesarean section due to breech presentation, premature
labor, and rupture of membranes. On physical examination the infant
was non-dysmorphic, appeared vigorous, had spontaneous
respirations, and the skin was pink and well perfused. Apgar scores
were 7 and 9 at 1 and 5 minutes, respectively. One hour after
admission to the neo- natal intensive care unit, the infant
developed tachypnea and nasal flaring with moderate subcostal and
substernal retractions....