Chronic Lung Disease
Signs and Symptoms
Factors that may increase a newborn's chance of developing chronic lung disease (CLD) include:
Immature Lungs -- Babies born prematurely often have immature lungs. As many as 70 percent to 75 percent of babies who are born before 26 weeks of gestational age develop CLD because their lungs have not developed completely. Gestational age is the number of weeks and days a fetus has developed since the beginning of the pregnancy, or gestation. A "full term" pregnancy is considered 40 weeks.
Exposure to High Concentrations of Oxygen -- The air we breathe normally is a blend of nitrogen, oxygen carbon dioxide and other gases. Oxygen normally makes up about 21 percent of the blend of gases we call "room air." One way to deliver more oxygen to a baby with immature lungs is to increase the fraction of oxygen in that blend, sometimes up to 100 percent. However, oxygen itself can be directly injurious to lung tissue. When a newborn is treated with oxygen for prolonged periods, especially high levels of oxygen, lung damage can occur.
Forced Breathing -- Some premature babies have a breathing problem called respiratory distress syndrome (RDS) and are treated with oxygen from a ventilator. These babies do not produce enough of a special lung fluid called surfactant, first identified by Dr. John Clements at UCSF Children's Hospital. Surfactant fluids normally lubricate the small airways of the lungs, preventing them from collapsing with each breath. But surfactant isn't produced in adequate amounts until later in pregnancy. As a result, an infant born very prematurely may be unable to inflate their own lungs, leading to respiratory distress syndrome. These babies may need help to force open their lungs, which can include the use of a ventilator and surfactant replacement therapy. As a result, this can cause lung damage due to increased air pressure from the ventilator, leading to CLD.
Irritation of the Lung Tissue -- Inflammation in the lung tissues is associated with immature lungs, infection, and exposure to oxygen and/or the use of a ventilator. The inflammation leads to more irritation and injury in the tissues of the newborn's lungs, which later can affect lung development or lead to scarring.
Fluid in the Lungs -- Fluid can build up in a newborn's lungs. This is typically caused by heart defects or being born by Caesarean section, although it also can result from being born premature and lung inflammation after prolonged mechanical ventilation.
Genetics -- Newborns can inherit lungs that are not fully mature at birth, which puts them at risk for developing CLD. Also, a family history of asthma or similar types of lung disease, such as reactive lung diseases, increases a newborn's chances of developing CLD.
Insufficient Nutrition -- Premature newborns who are undernourished or who do not get enough vitamin A or certain other nutrients may be more likely to develop CLD.
Babies with CLD will experience trouble breathing normally. Symptoms of this may include:
Diagnosis
Chronic lung disease (CLD) is usually diagnosed through a chest X-ray that shows scar tissues in the lungs, a characteristic of chronic lung disease.
Treatment
Treatment for chronic lung disease (CLD) depends on the severity of the condition. Therapy involves vaccinations to ward off infections, and oxygen to help a baby breath normally until their lungs improve. Some babies may need a medicine, called a diuretic, which makes them pass more urine to remove extra fluid from around their lungs.
Although for some babies their need for oxygen therapy may stop before they go home, others may require continued treatment after they've left the hospital. Before going home, your doctors and nurses will teach you how to give oxygen therapy and other medications, such as inhaled treatments, to your baby.
Copyright © 2002 - 2008 The Regents of the University of California