A bimodal form of alveolar behaviour induced by a defect in lung surfactant--a possible mechanism for sudden infant death syndrome.

It is proposed that in the presence of a defective surfactant at a critical period in lung development, large areas of the lungs may collapse suddenly, greatly reducing oxygen stores, producing a right-to-left shunt, and deranging the breathing control system. Yet the situation may be reversed just as rapidly to an apparently normal one if the child responds appropriately. Such events may be repeated, unnoticed until either the condition improves or the child fails to respond in time. The latter situation may be one mechanism for a proportion of sudden and unexplained infant deaths.