Lung physiological and metabolic changes in lambs with congenital diaphragmatic hernia after administration of prenatal maternal corticosteroids

Background/Purpose: Improved outcomes of preterm infants born to mothers tr eated prenatally with corticosteroids have been documented. The authors inv estigated the role of prenatal maternal corticosteroid therapy in congenita l diaphragmatic hernia (CDH). Methods: Five CDH lambs of ewes given 0.5 mg/kg betamethasone intravenously 24 hours before delivery (single-dose), four CDH lambs of ewes similarly d osed at 48 and 24 hours before delivery (double-dose), five untreated CDH l ambs and five control lambs were studied. After 2 hours of ventilation, com pliance. arterial oxygen (pO(2)) and carbon dioxide (pCO(2)) concentrations were recorded. Lavage protein and phospholipid levels were measured, and l ung tissue was analyzed for antioxidant enzyme activity (AOE). Results: No improvement in gas exchange was noted in either treatment group . Significant increases in compliance (P = .02) were noted in the double-do se steroid group, which were different from that of untreated CDH lambs or controls. Minimal changes in AOE activities were seen with steroid administ ration. Conclusions: Although the metabolic changes were not significant, the marke d improvement in compliance seen in the double-dosed steroid group suggests a potential role for prenatal maternal corticosteroids in CDH. Further tim ing and dosage studies are warranted in this model. J Pediatr Surg 34:354-3 56 Copyright (C) 1999 by W.B. Saunders Company.