The pharmacological treatment of newborn diaphragmatic hernia — update 1987

Before the mid 1970s, neonates with diaphragmatic hernias (CDH) had a survival rate of 40%. Since then increased interest has been focused on the pulmonary artery and its hypertension (the persistent fetal circulation) and the pharmacologic treatment of this pathophysiology. Our initial pharmacologic experience left us with much information and even more unanswered questions. While other series were encouraging, they also showed a survival rate of about 50%. The following problems are associated with pulmonary vasodilator therapy: (1) there is no specific pulmonary vasodilator and the response is often unpredictable; (2) the pulmonary arterioles in these babies are abnormal and appear in many instances anatomically incapable of responding; (3) cardiac output may be affected secondary to inotropic or chronotropic side effects of vasodilators; and (4) the effect of a vasodilator on the pulmonary vasculature under hypoxic conditions is unknown. Moreover, we have yet to identify at birth which CDH babies require this treatment, and we must find improved pharmacologic agents that will more specifically dilate the constricted pulmonary vascular bed with minimal effect on the systemic circulation. Although some attempts at pharmacological manipulation of the pulmonary vascular bed continue in most centers, including ours, there are many other innovations in the perioperative management which require further evaluation, among them extracorporeal membrane oxygenation, high-frequency oscillation and possibly lung transplantation in the future.