Babies who are born very prematurely or who have respiratory problems shortly after birth are at risk for bronchopulmonary dysplasia (BPD), sometimes called chronic lung disease. Although most infants fully recover with few long-term health problems, BPD can be serious and need intensive medical care.
Babies aren't born with BPD. It develops when premature infants with respiratory distress syndrome (RDS) need help to breathe for an extended period, which can lead to inflammation (swelling) and scarring in the lungs.
Bronchopulmonary dysplasia (brahn-ko-PUL-moh-nair-ee dis-PLAY-zhee-uh) involves abnormal development of lung tissue. It most often affects premature babies, who are born with underdeveloped lungs.
"Dysplasia" means abnormal changes in the structure or organization of a group of cells. The cell changes in BPD take place in the smaller airways and lung alveoli, making breathing difficult and causing problems with lung function.
Along with asthma and cystic fibrosis, BPD is one of the most common chronic lung diseases in children. According to the National Heart, Lung, and Blood Institute (NHLBI), there are between 5,000 and 10,000 cases of BPD every year in the United States.
Babies with extremely low birth weight (less than 2.2 pounds or 1,000 grams) are most at risk for developing BPD. Although most of these infants eventually outgrow the more serious symptoms, in rare cases BPD — in combination with other complications of prematurity — can be fatal.
Causes of BPD
Most BPD cases affect premature infants (preemies), usually those who are born more than 10 weeks early and weigh less than 4.5 pounds (2,000 grams). These babies are more likely to develop RDS (also called hyaline membrane disease), which is a result of tissue damage to the lungs from being on a mechanical ventilator for a long time.
Mechanical ventilators do the breathing for babies whose lungs are too immature to let them breathe on their own. Oxygen is delivered to the lungs through a tube inserted into the baby's trachea (windpipe) and is given under pressure from the machine to properly move air into stiff, underdeveloped lungs.
Sometimes, for these babies to survive the amount of oxygen given must be higher than the oxygen concentration in the air we commonly breathe. This mechanical ventilation is essential to their survival. But over time, the pressure from the ventilation and excess oxygen intake can injure a newborn's delicate lungs, leading to RDS.
Almost half of all extremely low birth weight infants will develop some form of RDS. RDS is considered BPD when preemies still need oxygen therapy at their original due dates (past 36 weeks' postconceptional age).
BPD also can be due to other problems that can affect a newborn's fragile lungs, such as trauma, pneumonia, and other infections. All of these can cause the inflammation and scarring associated with BPD, even in a full-term newborn or, very rarely, in older infants and children.
Among premature babies who have a low birth weight, white male infants seem to be at greater risk for developing BPD, for reasons unknown to doctors. Genetics may play a role in some cases of BPD, too.
Important factors in diagnosing BPD are prematurity, infection, mechanical ventilator dependence, and oxygen exposure.
BPD is usually diagnosed if an infant still needs additional oxygen and continues to show signs of respiratory problems after 28 days of age (or past 36 weeks' postconceptional age). Chest X-rays may be helpful in making the diagnosis. In babies with RDS, the X-rays may show lungs that look like ground glass. In babies with BPD, the X-rays may show lungs that appear spongy.
Treatment of BPD
No available medical treatment can immediately cure bronchopulmonary dysplasia. Treatment is focused on supporting the breathing and oxygen needs of infants with BPD and to help them grow and thrive.
Babies first diagnosed with BPD receive intense supportive care in the hospital, usually in a neonatal intensive care unit (NICU) until they can breathe well on their own, without the support of a mechanical ventilator.
Some babies also may get jet ventilation, a continuous low-pressure ventilation that helps minimize the lung damage from ventilation that contributes to BPD. Not all hospitals use this procedure to treat BPD, but some with large NICUs do.
Infants with BPD are also treated with different kinds of medicines that help to support lung function. These include bronchodilators (such as albuterol) to help keep the airways open, and diuretics (such as furosemide) to reduce fluid buildup in the lungs.
Severe cases of BPD might be treated with a short course of steroids. This strong anti-inflammation medicine has some serious short-term and long-term side effects. Doctors would only use it after a discussion with a baby's parents, informing them of the potential benefits and risks of the drug.
Antibiotics are sometimes needed to fight bacterial infections because babies with BPD are more likely to develop pneumonia. Part of a baby's treatment may involve the administration of surfactant, a natural lubricant that improves breathing function. Surfactant production may be affected in babies with RDS who have not yet developed BPD, so they might be given natural or synthetic surfactant to help protect against BPD.
Also, babies sick enough to be hospitalized with BPD may need feedings of high-calorie formulas through a gastrostomy tube (G-tube). This tube is inserted through the abdomen and delivers nutrition directly to the stomach so that babies get enough calories and start to grow.
In severe cases, babies with BPD cannot use their gastrointestinal systems to digest food. These babies require intravenous (IV) feedings — called TPN, or total parenteral nutrition — made up of fats, proteins, sugars, and nutrients. These are given through a small tube inserted into a large vein through the baby's skin.
The time spent in the NICU for infants with BPD can range from several weeks to a few months. The average length of intensive in-hospital care for babies with BPD is 120 days. Even after leaving the hospital, a baby might need continued medication, breathing treatments, or even oxygen at home.
Most babies are weaned from supplemental oxygen by the end of their first year, but a few with serious cases may need a ventilator for several years or, rarely, even their entire lives.
Improvement for any baby with BPD is gradual. Many babies diagnosed with BPD will recover close to normal lung function, but this takes time. Scarred, stiffened lung tissue will always not work as well as it should. But as infants with BPD grow, new healthy lung tissue can form and grow, and might eventually take over much of the work of breathing for damaged lung tissue.
Complications of BPD
After coming through the more critical stages of BPD, some infants still have longer-term complications. They are often more at risk for respiratory infections, such as influenza (the flu), respiratory syncytial virus (RSV), and pneumonia. And when they get an infection, they tend to get sicker than most children do.
Another respiratory complication of BPD includes excess fluid buildup in the lungs, known as pulmonary edema, which makes it more difficult for air to travel through the airways.
Occasionally, kids with a history of BPD also may develop complications of the circulatory system, such as pulmonary hypertension in which the pulmonary arteries — the vessels that carry blood from the heart to the lungs — become narrowed and cause high blood pressure. But this is not common.
Side effects from being given diuretics to prevent fluid buildup can include dehydration; kidney stones; hearing problems; and low potassium, sodium, and calcium levels. Infants with BPD often grow more slowly than other babies, have problems gaining weight, and tend to lose weight when they're sick. Premature infants with severe BPD also have a higher incidence of cerebral palsy.
Overall, though, the risk of serious permanent complications from BPD is fairly small.
Caring for Your Baby
Parents play a critical role in caring for an infant with BPD. An important precaution is to reduce your baby's exposure to potential respiratory infections. Limit visits from people who are sick, and if your baby needs childcare, pick a small center, where there will be less exposure to sick kids.
Making sure that your baby receives all recommended vaccinations is another important way to help prevent problems. And keep your child away from tobacco smoke, particularly in your home, as it is a serious respiratory irritant.
If your baby requires oxygen at home, the doctors will show you how to work the tube and check oxygen levels.
Children with asthma-type symptoms may need bronchodilators to relieve asthma-like attacks. You can give this medicine to your child with a puffer or nebulizer, which produces a fine spray of medicine that your child then breathes in.
Because infants with BPD sometimes have trouble growing, you might need to feed your baby a high-calorie formula. Formula feedings may be given alone or as a supplement to breastfeeding. Sometimes, babies with BPD who are slower to gain weight will go home from the NICU on G-tube feedings.
When to Call the Doctor
Once a baby comes home from the hospital, parents still need to watch for signs of respiratory distress or BPD emergencies (when a child has serious trouble breathing).
Signs that an infant might need immediate care include:
- faster breathing than normal
- working much harder than usual to breathe:
- belly sinking in with breathing
- pulling in of the skin between the ribs with each breath
- growing tired or lethargic from working to breathe
- more coughing than usual
- panting or grunting
- pale, darker, or bluish skin color that may start around the lips or fingernails
- trouble feeding or excess spitting up or vomiting of feedings
If you notice any of these symptoms in your baby, call your doctor or get emergency medical care right away.