Hyaline membrane disease, or infantile respiratory distress syndrome, is a lung disease that occurs only in very premature babies. The more premature the infant, the greater the risk of developing the condition. Of babies born 8 weeks premature, 75% will be affected.
Surfactant is a fluid essential within the lungs to enable them to open and fill with air after birth. It is not produced in adequate quantity in some premature babies, so their lungs do not open and they cannot obtain sufficient air and oxygen. The hyaline membrane that lines the tiny airways within the lungs is responsible for producing surfactant. Hyaline membranes are not anatomical structures but restrictive membranes, formed by proteins exuded from the tiny blood vessels in the immature lungs of premature babies, which decrease the elasticity of the lungs and make breathing more difficult.
The condition develops some hours after birth, when the baby starts to breath rapidly, grunt with each breath, and has very marked movements of the chest and abdomen as it tries to breath. The baby will become blue in colour, and lapse into a coma.
The diagnosis is confirmed by a chest X-ray while a special test performed on a sample of the amniotic fluid in which the baby floats in the womb can assess the risk of developing the disease before birth. It can be prevented if the mother is given an injection of a steroid at least 48 hours before the birth. Every effort is made to delay a birth until the 48 hours has elapsed.
Once the disease is present, oxygen is given in a humidicrib. Death is common without treatment, but if the baby survives for 48 hours, it is almost certain to recover. A small number of children have permanent lung damage.