Bronchopulmonary Dysplasia

What Is Bronchopulmonary Dysplasia?

Bronchopulmonary dysplasia or BPD is a chronic lung disease of babies. BPD develops most commonly in the first 4 weeks after birth. BPD mostly occurs in babies who are born more than 4 weeks before their due dates, although sometimes the babies are full term. In BPD, the lungs do not work properly, and the babies have trouble breathing. They need extra oxygen and may even need help from a breathing machine. Doctors think babies develop BPD because their lungs are sensitive to something damaging in the environment, such as high levels of oxygen, a breathing machine, or an infection. Premature babies are also at risk for complications in other parts of the body that are not fully mature, including the heart, kidneys, brain, stomach, intestines, and eyes.

With new and better treatments today, most babies with BPD live. In severe cases, the baby may die.

BPD is different from respiratory distress syndrome (RDS), which occurs in the lungs of premature infants because their lungs do not produce enough surfactant (a liquid material that coats the inside of the lungs, making it easy to breathe). In the past, doctors thought that BPD was a disease mostly in babies who survived RDS. They believed that the treatment of RDS with a breathing machine and extra oxygen caused BPD. Today, babies with RDS are treated with surfactant replacement therapy and do very well. With this new treatment, BPD is not common in babies born early and weighing 3 pounds or more.

What Causes Bronchopulmonary Dysplasia?

Bronchopulmonary dysplasia (BPD) does not develop in all infants for the same reasons. Doctors now believe that BPD occurs because of the way a particular baby's lungs respond to the outside environment in the first hours or days after birth. Whether BPD actually develops will depend on the immaturity of the lungs, the irritants in the environment, and other factors that may not be known, such as exposures in the womb or inherited traits. Factors that might contribute to BPD include:

• Immaturity of the lungs
• Giving the baby a high level of oxygen
• Putting the baby on a breathing machine
• Infections
• Pneumonia

The lungs in babies born earlier than 30 weeks are often not formed well enough to support breathing. The poorly formed lungs do not provide enough surface area or the fine network of blood vessels necessary to allow the oxygen from the air to travel into the blood stream, or for the carbon dioxide to travel from the blood across the surface of the lungs into the air. This process of oxygen and carbon dioxide transfer across the lungs is called gas exchange. Over time, the lungs may also develop other complications, which may make the gas exchange more difficult.

Many babies with breathing problems have low oxygen levels in the blood and are given extra oxygen to protect the brain, heart, liver, and kidneys from damage caused by low oxygen. However, high levels of extra oxygen can harm the lungs, cause inflammation, and slow or stop the lung growth in babies born very early. Babies who need a high level of extra oxygen for a period of time may develop BPD.

Babies who cannot breathe on their own have breathing failure. Many of these babies are put on a breathing machine to help them breathe. The machine pushes air into the baby's lungs. The pressure that the machine uses to push the air can irritate the airways and the lungs and cause them to become inflamed.

Babies can be exposed to infections both in the womb and after birth. Infections in babies born early can harm their less-formed lungs and cause them to become inflamed. Lung infections also increase the baby's need for extra oxygen and for help with breathing.

Who Is At Risk for Bronchopulmonary Dysplasia?

Factors like lower weight and less time in the mother’s womb can increase a baby’s risk of developing bronchopulmonary dysplasia (BPD). Today, most babies with BPD (9 of 10) weigh 1,500 grams (about 3½ pounds), or less, at birth. Babies born weighing less than 1,000 grams (about 2 pounds) are at very high risk. About one of three of these babies develops BPD. These small babies can develop BPD even if they do not have respiratory distress syndrome or need a breathing machine.

Today, larger and more mature babies rarely develop BPD, due to better treatment of breathing problems in newborns. The larger and more mature babies who develop BPD usually have had serious and prolonged breathing problems in the first days of life.

About 5,000 to 10,000 babies in the United States develop BPD each year. Because more babies weighing less than 3 pounds live past 4 weeks, more babies develop BPD today than 30 years ago.

What Are the Signs and Symptoms of Bronchopulmonary Dysplasia?

Babies with bronchopulmonary dysplasia (BPD) struggle to breathe, and they show signs of distress that are found with other breathing problems. The severity of the signs of breathing difficulty will vary, depending on the severity of disease and lung maturity. These signs include:

• Rapid, shallow breathing (tachypnea)
• Sucked-in ribs and chest (retraction)
• Cough
• Movement of the chest and stomach (abdomen) in the opposite direction with every breath (see-saw breathing)
• Wheezing (a whistling sound when the baby breathes)
• "Craning" the neck (raising or stretching the neck by using the neck muscles to push more air into the lungs)
• Poor posture of the neck, shoulders, and upper body
• Repeated periods of bluing (the blue skin colour is due to the low amount of oxygen in the blood)

If a baby develops any of the above signs of respiratory distress, the doctors will look for the cause, which might be BPD but also might be another respiratory problem. Doctors also have to make sure that the baby does not have a problem with the function of the heart.

How Is Bronchopulmonary Dysplasia Diagnosed?

It is difficult to make a diagnosis of bronchopulmonary dysplasia (BPD) before a baby is about 14 to 30 days old. To diagnose BPD, doctors consider whether the baby had a lung injury within a few days of birth and continues to need extra oxygen after receiving oxygen treatment for a certain period of time. A chest x ray may help confirm abnormal lung development.

Doctors will grade the severity of the BPD as mild, moderate, or severe depending on the amount and length of time the baby needs extra oxygen.

How Is Bronchopulmonary Dysplasia Treated?

No treatment is specific for bronchopulmonary dysplasia (BPD); rather, treatment is supportive. Doctors provide treatment to help the baby breathe better. They make sure the baby has enough oxygen; is properly fed, kept warm, and treated for infections; and is given the right amount of fluids and nourishment. This gives the baby's lungs time to mature. Babies with BPD are usually treated in a special intensive care unit (ICU) for newborns (neonatal ICU). Some babies may be treated in the neonatal ICU even before doctors know that the babies have BPD, because they may have been born premature, needed treatment for respiratory distress syndrome (RDS), or had other problems. Doctors can tell if a baby has BPD only after the baby is several weeks old.

Treatment for BPD is done in three stages. The stages are:

• Treatment for RDS at birth (before doctors can tell if the baby has BPD)
• Treatment after doctors know the baby has BPD
• Home care after the baby leaves the hospital

Treatments for babies who show signs of RDS but who are not yet diagnosed with BPD include:

• Giving extra surfactant. Surfactant is a fluid with special properties that normally coats the inner surface of healthy, mature lungs. Surfactant makes the lungs easy to open and prevents them from collapsing shut. A lung that inflates normally can absorb more oxygen into the bloodstream. Extra surfactant is given directly into the lung by a breathing tube placed through the baby's mouth or nose to the windpipe. With this new treatment, BPD is not common in babies born early and weighing 3 pounds or more.
• Giving extra oxygen to make sure the baby is getting enough oxygen in the blood.
• Treating the baby with a breathing machine (ventilator) if he or she needs help with breathing. The machine is connected to a breathing tube that runs through the mouth or nose into the windpipe. The breathing machine can be set to help a baby breathe or to completely control a baby's breathing. It also gives the amount of oxygen the baby needs. With breathing help, the baby's lungs have a chance to develop. Breathing machines today do not cause as much injury to the airways and lungs as the machines used in the past. Therefore, babies who need breathing machines don't always develop BPD.
• Giving medicines to relieve inflamed and swollen airways and improve the flow of air in and out of the lungs.
• Keeping a close watch on the amount of fluids the baby is taking in. This avoids fluid buildup in the lungs (pulmonary oedema).
• Treating patent ductus arteriosus, a circulatory problem sometimes found in premature infants.
• Giving special feedings and formula to prevent malnutrition and promote growth. Nutrition is important in the growth and development of the lungs.

Once doctors know a baby has BPD, some or all of the following treatments are continued in the ICU:

• Using the breathing machine until the baby can breathe on his or her own
• Giving extra oxygen until the baby can breathe well enough on room air
• Giving medicines such as bronchodilators (to improve the flow of air in and out of the lungs) and corticosteroids (to reduce the swelling and inflammation of the airways)
• Keeping a close watch on the amount of fluids the baby is taking in, to avoid fluid buildup in the lungs
• Giving medicines (diuretics) that help remove extra fluid from the lungs
• Giving antibiotics to control infections
• Giving the baby liquid feedings through a needle in a vein (intravenous) to provide extra nutrition to help the baby get stronger and healthier
• Giving special feedings and formula to help the baby grow stronger and healthier
• Providing physical therapy to help make the baby's muscles grow stronger and to help the lungs stay clear of mucus

Today, most babies with BPD recover. They may spend several weeks or months in the hospital. However, the best place for a baby to grow and develop is at home with his or her family, in a loving and familiar environment. After the baby goes home:

• It is important that the parents know about the signs and symptoms and treatment of BPD.
• The baby may continue to have some breathing problems and may remain in poor health.
• The baby may still need extra oxygen and may also need a breathing machine.
• The baby will need a paediatrician to give regular checkups, immunizations (shots), and treat illnesses.
• Nurses, respiratory and physical therapists, and social services may be needed.
• Parents and family members play an important role by being loving and involved with the baby and by providing consistent care.

How Can Bronchopulmonary Dysplasia Be Prevented?

Small babies born very prematurely have the greatest chance of developing bronchopulmonary dysplasia (BPD). Programs of regular prenatal care for women at high risk of early delivery can lower the number of babies born early.

For some women, taking corticosteroid medications may lower the chance of having a premature or low-birth-weight baby. However, only one course of corticosteroid should usually be used for this purpose before birth.

Living With Bronchopulmonary Dysplasia

The signs and symptoms that continue after the baby leaves the hospital can vary. Babies with bronchopulmonary dysplasia (BPD) are more likely than other babies to get colds, flu, and other infections that generally are mild in most children but can be life-threatening in babies with BPD. They may also continue to need extra oxygen. Some may need to use a breathing machine throughout early childhood.

Babies who survive BPD are at higher risk for complications after the usual childhood infections. To be safe, they are often treated in the hospital for respiratory infections.

Babies who survive BPD may grow more slowly than normal. The slow growth often lasts into their second year of life. They usually remain smaller than normal children of the same age. Like most children, their lung growth is almost complete at 8 years of age. However, they may have some lasting problems with their lung function even when they are adults.

In very severe cases, they may have a small risk of some long-term problems. These include:

• Poor coordination and muscle tone
• Trouble walking
• A hard time exercising
• Eye and hearing problems
• Problems with learning

The risk of these problems is very small. Parents should not assume that their child will develop these problems. If they do occur, parents and families can get information about these problems from their doctors.

Parents can take a number of steps to help their babies recover and grow as normally as possible. These include:

• Calling your baby's doctor if you see any signs of respiratory infection. The symptoms include irritability, fever, stuffy nose, cough, changes in breathing pattern, and wheezing.
• Keeping your baby away from large daycare centers and crowds to avoid germs that cause colds, flu, and other infections.
• Keeping your baby away from cigarette smoke, dust, pollution, and other things in the air that irritate the lungs.
• Making sure that the baby and your other children get all their childhood immunizations. Doctors now recommend immunizations to protect against a virus called the respiratory syncytial virus.

Key Points

• Bronchopulmonary dysplasia (BPD) is a serious, chronic lung disease in newborn babies. It occurs mostly in small babies of low birth weights who are born 3 or more months before their due date.
• About 5,000 to 10,000 babies in the United States develop BPD each year. Today, most of these babies survive.
• Doctors believe that BPD occurs because the lungs of these babies are susceptible to injury during the first hours or days after birth. Factors that may contribute to BPD include:
  • Treating the baby with a breathing machine
  • Giving the baby extra oxygen
  • Infections
  • Pneumonia

When babies are treated with a breathing machine or given extra oxygen, it is very important for parents to understand that these are needed treatments and should not be avoided for fear of BPD.

• The signs of BPD result from the breathing difficulty and include:
  • Rapid shallow breathing
  • Sucked-in ribs and chest
  • Cough
  • Movement of the chest and stomach in the opposite direction with every breath
  • Wheezing
  • "Craning" the neck
  • Poor posture of the neck, shoulders, and upper body
  • Repeated periods of bluing (the blue skin colour is due to the low amount of oxygen in the blood)

• Doctors diagnose BPD when the baby has had lung injury within a few days of birth and continues to need extra oxygen after having been on oxygen treatment for a certain period of time.
• There is no specific treatment for BPD. Doctors provide treatment to help the baby breathe better. They make sure the baby has enough oxygen; is properly fed, kept warm, and treated for infections; and is given the right amount of fluids and nourishment.
• Babies with BPD are usually treated in a special intensive care unit (ICU) for newborns (neonatal ICU).
• Most babies who develop BPD recover. They may spend several weeks or months in the hospital.
• Babies who survive BPD are at higher risk of complications after the usual childhood infections.