Bronchopulmonary dysplasia is a chronic lung disorder caused by repetitive lung injury.
Bronchopulmonary dysplasia is a chronic lung disorder that occurs most often in infants who were very premature and were born with a severe lung disorder (such as respiratory distress syndrome), particularly infants who needed treatment with a ventilator for more than a few weeks after birth. The delicate tissues of the lungs can be injured when the air sacs are over-stretched by the ventilator or when they are exposed to high oxygen levels for a time. As a result, the lungs become inflamed, and additional fluid accumulates within the lungs. Affected infants may not develop the normal number of air sacs. Full-term newborns who have lung disorders (such as pneumonia) occasionally develop bronchopulmonary dysplasia. Doctors now realize that bronchopulmonary dysplasia also may occur in some infants who were very premature but who did not have respiratory distress requiring a ventilator.
Symptoms and Diagnosis
Affected newborns usually breathe rapidly and may have respiratory distress, with drawing in of the lower chest while breathing in, and low levels of oxygen in the blood, causing a bluish discoloration of the skin (cyanosis). In some severely affected newborns, more than the usual amount of time is needed for air to leave the lungs during expiration, and this delay can lead to air trapping, in which the lungs become over-expanded.
The diagnosis of bronchopulmonary dysplasia is made in infants who were born prematurely, who have received ventilation for a prolonged time (generally for several weeks or months), and who have signs of respiratory distress and a prolonged need for supplemental oxygen. The diagnosis is supported by measurement of low levels of oxygen in the blood and results of a chest x-ray.
Although a few infants with very severe bronchopulmonary dysplasia die even after months of care, most infants survive. Over several months the seriousness of the lung injury diminishes as healthy lung tissue grows. However, later on, these children are at increased risk of developing asthma and viral pneumonia, such as that caused during winter months by RSV infection.
Prevention and Treatment
After discharge from the hospital, infants with bronchopulmonary dysplasia should not be exposed to cigarette smoke or fumes from a space heater or wood-burning stove. They should be protected as much as possible from exposure to people who have upper respiratory tract infections. These children should be protected from RSV infection by receiving doses of palivizumab, a specific antibody to that virus. This antibody must be injected monthly during the fall and winter when RSV infections occur in the community.
Ventilators are used only when absolutely necessary and then are used at the lowest possible settings to avoid injury to the lungs. Newborns are taken off ventilators as early as is safe.
In infants with bronchopulmonary dysplasia, supplemental oxygen provided through a small tube placed in the infant's nostrils may be needed initially to prevent cyanosis. Some infants with bronchopulmonary dysplasia need supplemental oxygen for months or longer.
Good nutrition is crucial to help the infant's lungs grow and to keep the new lung tissue healthy. Thus, the damaged areas of lung become less and less important relative to the overall size of the infant's lungs.
Because fluid tends to accumulate in the inflamed lungs, sometimes the daily intake of fluids is restricted, and diuretics may be used to increase the rate of excretion of fluid in the urine.
Last full review/revision February 2009 by Arthur E. Kopelman, MD