New interpretation and management of dry lung syndrome: a case report.

A premature female infant with life-threatening respiratory distress which was diagnosed as 'dry lung syndrome' is reported. The mother had 4 weeks of large volume leakage of the amniotic fluid due to premature rupture of the fetal membranes (PROM) at 23 weeks' gestation. The infant was born after 27 weeks' gestation (birthweight, 1016 g) and was suffering severe respiratory distress. Although a chest radiogram and gastric juice microbubble test did not improve the possibility of respiratory distress syndrome (RDS), very high ventilator settings did not improve her respiratory disorders. Considering the infant's deteriorating respiratory status and the prolonged leakage of the amniotic fluid, we suspected the presence of pulmonary hypoplasia. Although an attempt at high frequency oscillation (HFO) to rescue this infant had no effect, intratracheal instillation of epinephrine (EP) showed dramatic improvement of her respiratory status. This clinical course showed that the patient did not have pulmonary hypoplasia but might have severe airway obstruction and this airway obstruction may be the major cause of 'dry lung syndrome'. We postulate that when a newborn with suspected pulmonary hypoplasia is unresponsive to respiratory support. HFO should be administered. If HFO is ineffective in relieving the respiratory distress, one should suspect the presence of airway collapse and administer a bronchodilator such as EP. If the infant improves, a diagnosis of 'dry lung syndrome' may be assumed.