PERSISTENCE OF FETAL CIRCULATION

The causal relationship between certain pathophysiologic responses of the fetal circulation and the clinical syndrome of persistence of the fetal circulation [PFC], and the possible association between similar untoward circulatory adjustments and the development of hyaline membrane disease was discussed. These observations provide a rational basis for the further investigation of potentially beneficial but dangerous vasoactive agents, such as tolazoline, in treating severe PFC and possibly other pulmonary diseases in which persistent pulmonary arteriolar vasospasm contributes to the morbidity and mortality. At present the use of these agents should be limited to those severely ill infants with marked elevation in pulmonary artery pressure, in the presence of normal or elevated systemic pressure, who do not have congenital heart disease and are unresponsive to other management. PFC seems firmly and appropriately established as identifying a syndrome of prolonged usually reversible pulmonary vascular obstruction in the neonate.