Neonatal respiratory distress syndrome is a form of respiratory distress usually occurring within 4 hours of birth and persistently worsening for 48 to 72 hours. If not fatal, it resolves by 72 hours. Surfactant replacement therapy has shortened the duration of the disease and reduced mortality by 40%.
Surfactant deficiency results in high alveolar surface tension; with each breath the baby must reinflate the collapsed alveoli. Thus every breath is like the first - a large effort for relatively poor expansion.
This condition is now being treated with administration of synthetic or animal surfactant.