Studies on infants with type II respiratory distress syndrome

Abstract

A group of infants is described who seem to share clinical, biochemical, and physiologic similarities. The are prematurely born, but usually late in gestation, and frequently have a history of heavy maternal sedation or are delivered by cesarean section. Mild depression is often present at birth, and respiratory symptoms of grunting, chest-wall retraction, tachypnea, and flaring of the alae nasae appear soon after birth. The chest radiograph typically shows heavy central bronchovascular markings and overdistention of peripheral lung fields. These infants can be hyperoxygenated in 100 per cent oxygen throughout the course of their disease. There is early evidence of mildly to moderately severe combined metabolic and respiratory acidosis. They are normotensive for their size, and no significant shunting can be demonstrated through either the foramen ovale or the ductus arteriosus. Left ventricular output is within the normal range for size. The radiologic and physiologic findings usually permit differentiation from clinical hyaline membrane disease. Symptoms of respiratory distress subside gradually over the first 3 to 7 days of life, and residual pulmonary symptoms or radiologic abnormalities are absent. Subsequent motor and mental development are within normal limits.