EXOGENOUS SURFACTANT IS DISTRIBUTED IN BOTH LUNGS OF NEONATAL RATS WITH CONGENITAL DIAPHRAGMATIC-HERNIA

Exogenous surfactant therapy may improve survival in children with con genital diaphragmatic hernia (CDH) and hypoplastic, immature lungs. We assumed that surfactant would be distributed unevenly, with less depo sited in the ipsilateral, most hypoplastic lung. Therefore, we studied the distribution of exogenous surfactant in newborn rats with CDH whi ch was induced by oral administration of 100 mg 2,4-dichloro-phenyl-p- nitrophenylether (Nitrofen) on gestational day 10. Following a cesarea n section newborns were ventilated for one hour in a standardized way with a pressure of 25 cm H2O (reduced to 17 cm H2O after 30 minutes), FiO(2) 1.0 and PEEP 3 cm H2O. Surfactant mixed with colored microspher es was administered endotracheally (dose 25 mg/ml; 50 mu l). The numbe r of microspheres in the lungs was measured by spectrophotometry. Exog enous surfactant was deposited in both lungs in CDH: The median number of microspheres per mg dry lung weight was 3710 (range 1080-5990) in the left, severely hypoplastic lungs versus 3510 (1520-4360) microsphe res in the right lungs. This offers good prospects to apply surfactant in children with CDH in randomized trials not hampered by major diffe rences in lung expansion and resulting pneumothorax.