Respiratory distress syndrome (infants)

Alternative names:

hyaline membrane disease; RDS

Definition:

A lung disorder that primarily affects premature infants and causes increasing difficulty in breathing. See also ARDS (adult respiratory distress syndrome).

Causes, incidence, and risk factors:

Respiratory distress syndrome usually occurs in premature infants; a full-term infant rarely will be affected. The disease is caused by a lack of pulmonary surfactant, a chemical that normally appears in mature lungs. Pulmonary surfactant reduces the surface tension within the air sacs of the lungs, preventing a collapse of these air sacs and allowing them to inflate more easily. In respiratory distress syndrome, there is atelectasis, or collapse of these air sacs with a decrease in lung volume, and an inability to exchange oxygen and carbon dioxide within the lung. The symptoms usually appear shortly after birth and become progressively more severe. Risk factors are prematurity, diabetes mellitus in the mother, and stress during delivery that produces acidosis in the newborn at the time of delivery.