Abnormal pulmonary vasoconstriction in the newborn

[摘要] Since the classic perinatal lamb experiments of Dawes and associates1 led to the description of a transitional circulation of the newborn, pediatricians have responded by an increasing appreciation of this concept. Independent studies indicating both indirectly and directly the existence of this normal intermediate circulatory pattern for the human were reported shortly thereafter.2-4 These investigations were later supplemented by elegant studies5 so that a very clear understanding of the usual and normal time sequence of the change over from fetal to adult circulatory pathways in the healthy term infant has been with us for over a decade. The essential part of this change is one of a reduction in tone of the pulmonary vascular bed during the first six hours after birth followed by an increase in tone of the ductus arteriosus.

[学科分类] 儿科学