Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia, or BPD, is a serious lung condition that affects mostly babies who are born premature and have a very low weight at birth (less than 1500 grams or 3.3 pounds).

Lungs. Source:Wikimedia Commons

Other Names

• Neonatal chronic lung disease (CLD)
• Evolving chronic lung disease
• Chronic lung disease of infancy
• BPD

Signs and Symptoms

Most babies who get bronchopulmonary dysplasia (BPD) are born with respiratory distress syndrome (RDS). The signs and symptoms of RDS at birth are:

• Rapid, shallow breathing.
• Sharp pulling in of the chest below the ribs with each breath.
• Grunting sounds during exhalation.
• Flaring of the nostrils during breathing.

Babies with severe BPD may also develop:

• Pulmonary arterial hypertension, continuous high blood pressure in the blood vessels that carry oxygen-poor blood from the right ventricle in the heart to the small arteries in the lungs.
• Cor pulmonale, failure of the right side of the heart caused by ongoing high blood pressure in the pulmonary artery and right ventricle.

Causes

Babies that are born more than 10 weeks before their due dates and/or weigh less than 1000 grams (2.5 pounds) at birth usually are born with what is called respiratory distress syndrome (RDS). Their lungs haven't yet developed enough to make surfactant, which is a liquid that coats the inside of the lungs and keeps them open so that the baby can breathe in air once he or she is born. As a result, these babies are usually put on oxygen and a breathing machine at birth; either a ventilator (also known as a respirator) or a nasal continuous positive airway pressure (NCPAP) machine. This can prevent damage to their brains and other body organs from lack of oxygen. They also are given surfactant.

It is believed that a baby gets bronchopulmonary dysplasia (BPD) as a result of the way his or her lungs respond to some of the procedures mentioned above, including:

• High levels of oxygen: Doctors usually give oxygen to newborns with breathing problems to make sure that their brains, hearts, livers, and kidneys receive enough oxygen to do their jobs. But high levels of oxygen can cause inflammation in the lungs that can result in injury to the breathing passages. High levels of oxygen also can slow the normal development of the lungs in babies born very early.^[1]
• Pressure caused by mechanical ventilation: In the past, doctors wouldusually put newborns who couldn't breathe on their own on mechanical ventilators. These machines apply pressure to push air into the babies' lungs and this pressure can irritate the lungs and cause them to become more inflamed. Mechanical ventilation is a factor in most cases of BPD.
• Infections: Infections in babies born early can cause inflammation in their underdeveloped lungs. This narrows the breathing passages and makes it harder for the baby to breathe and also increases the baby's need for extra oxygen and help with breathing.

Diagnosis

It's hard to tell whether a baby with breathing problems has bronchopulmonary dysplasia (BPD) before he or she is about 14 to 30 days old. At this point, the baby should be showing improvement in the breathing problems. Instead, the baby's condition seems to be getting worse and he or she needs more oxygen or help from a breathing machine.

Doctors usually conduct a number of tests on newborns with breathing problems to make sure they diagnose their condition correctly. These tests include:

• Blood tests. Blood samples are checked to see whether the baby has enough oxygen in his or her blood.
• Chest x ray. A chest x ray takes a picture of the heart and lungs. It shows larger areas of air and changes from inflammation or infection. It also shows areas of the lung that have collapsed and may help confirm that the lungs aren't developing normally.^[2]
• Echocardiogram. This test uses sound waves to create a moving picture of the heart. Echocardiogram is used to rule out congenital heart defects or pulmonary arterial hypertension as the cause of the breathing problems.

With this information BPD is categorized as mild, moderate, or severe, depending on how much extra oxygen the baby needs and how long he or she needs it.

Treatment

The goals of treatment for babies with bronchopulmonary dysplasia (BPD) are to:

1. Reduce further injury to the lungs.
2. Provide nutrition and other support to help the lungs grow and recover.

Treatment is done in three stages:

• Treatment for respiratory distress at birth and before doctors know whether the baby has BPD.
• Treatment after doctors know the baby has BPD.
• Home care after the baby leaves the hospital.

Treatment of respiratory distress usually begins as soon as the baby is born, sometimes in the delivery room. Most infants who show signs and symptoms of respiratory distress syndrome (RDS) are quickly moved to a special intensive care unit called a neonatal intensive care unit (NICU). There they receive around-the-clock treatment from a group of health care professionals who specialize in treating premature infants.

Medications

Doctors usually give the baby medicines to reduce swelling in the airways and improve the flow of air in and out of the lungs; bronchodilators to improve the flow of air in and out of the lungs, Diuretics to help remove extra fluid from the lungs, and Antibiotics to control infections.

Breathing Support

These babies usually are put on a breathing machine to help them breathe, either a mechanical ventilator or a nasal continuous positive airway pressure (NCPAP) machine. ^[3] The ventilator is connected to a breathing tube that runs through the baby's mouth or nose into the windpipe. The ventilator can be set to help a baby breathe or to completely control a baby's breathing and it is adjusted to give the amount of oxygen the baby needs.

Today, more and more babies are receiving breathing support from an NCPAP machine, which pushes air into the baby's lungs through prongs in the nostrils.

With breathing help, the baby's lungs have a chance to develop. Breathing machines today don't cause as much injury to the airways and lungs as those used in the past.

Surfactant Replacement Therapy

The baby is given surfactant to open his or her lungs until the lungs have developed enough to start making their own surfactant. Surfactant is given through a tube that is attached to the breathing machine, which pushes the surfactant directly into the baby's lungs.

Other Types of Treatment

Other treatments for babies who show signs and symptoms of RDS and haven't yet been diagnosed with BPD include:

• Medicines
• Supportive therapy
• Treatment for patent ductus arteriosus, a condition that affects some premature infants

Supportive Therapy

Treatment in the NICU is designed to limit stress on the baby and meet his or her basic needs of warmth, nutrition, and protection. Such treatment usually includes:

• Using a radiant warmer or incubator to keep the baby warm and reduce the chances of infection.
• Ongoing monitoring of blood pressure, heart rate, breathing, and temperature through sensors taped to the baby's body.
• Using a sensor on a finger or toe to monitor the amount of oxygen in the baby's blood.
• Giving fluids and nutrients through a needle or tube inserted into a vein to prevent malnutrition and promote growth. Nutrition is critical to the growth and development of the lungs. Later, the baby may be given milk through a tube that is passed through his or her nose into the mouth.
• Monitoring fluid intake to make sure that fluid doesn't build up in the baby's lungs.

Once doctors know that the baby has BPD, some or all of these treatments are continued in the NICU:

• Babies with BPD are usually taken off the breathing machine slowly over time. They are often moved from the ventilator to an NCPAP machine until they can breathe on their own. This machine pushes air into the baby's lungs through prongs in the nostrils.
• The baby is likely to continue to need extra oxygen for some time. Once the baby no longer needs help breathing, he or she may get additional oxygen through prongs in the nostrils.
• Babies with moderate to severe BPD have an echocardiogram every 2 to 3 months to check their pulmonary artery pressure.

These babies also may need physical therapy to strengthen their muscles and help their lungs clear out mucus.

Today, most babies with BPD recover. They may spend several weeks or months in the hospital. But the best place for the baby's growth and development is at home with the family where he or she can be in a loving and familiar environment.

After the baby goes home:

• It's important for the parents to know about the symptoms and treatments for BPD. Parents and family members play an important role by being loving and involved with their babies and giving care.
• The baby may continue to have some breathing symptoms and may remain in poor health.
• He or she may still need extra oxygen and a breathing machine.
• He or she needs good nutrition and extra calories because of the extra work involved with breathing.
• Regular checkups and timely vaccinations from a pediatrician (a doctor who specializes in treating children) are important. A pediatrician also can treat any other illnesses that the baby may develop.
• The family also may need social services to help them take care of the baby's medical and nonmedical needs.

Prevention

There are certain things to help ensure that a baby isn't born before his or her lungs have developed completely.

They include:

• Seeing a doctor regularly during pregnancy
• Eating right
• Avoiding tobacco smoke, alcohol, and illegal drugs
• Controlling any ongoing medical conditions you have
• Preventing infection

The doctor may also recommend taking progesterone if there has been a prior preterm birth. This is a hormone that may help delay delivery.

The doctor may give injections of a corticosteroid medicine if it appears that the baby will be born too early. This medicine can speed up surfactant production and development of the lungs, brain, and kidneys in the fetus. Usually, within about 24 hours after starting taking the medicine, the fetus' lungs will work better. They also will respond better to surfactant treatment so that respiratory distress syndrome will not develop after delivery, or it will be relatively mild.

Living With Bronchopulmonary Dysplasia

A baby with bronchopulmonary dysplasia (BPD) may continue to have problems after he or she leaves the hospital. He or she may:

• Continue to need extra oxygen.
• Need to use a breathing machine throughout early childhood.
• Be more likely than other infants to get colds, flu, and other infections. This includes viral infections. These infections are usually mild in other children but can be life threatening in babies who have BPD.
• Have a greater chance of developing complications from the most common childhood infections. The doctor may want to put the baby in the hospital for treatment of a respiratory infection, to be safe.
• Grow more slowly than normal during the first year or two of life. Babies who survive BPD usually stay smaller than other children of the same age.

As with most other children, the lungs of babies who had BPD are almost completely grown by age 8. But these children may have some ongoing lung problems, even when they're adults.

Some babies with very severe BPD may develop some long-term problems. These include:

• Poor coordination and muscle tone
• Trouble walking and being active
• Eye and hearing problems
• Frequent breathing problems and infection
• Learning problems

The chances of developing these problems are very low. Parents shouldn't assume that their child will have these problems. If they do occur, parents and families can get information about these problems from the baby's doctors.

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

• Call the baby's doctor if there are any signs of respiratory infection. The symptoms include irritability, fever, stuffy nose, cough, changes in breathing pattern, and wheezing.
• Keep the baby away from large daycare centers and crowds to avoid germs that cause colds, flu, and other infections.
• Make sure that no one smokes in the home, and keep the baby away from cigarette smoke, dust, pollution, and other things in the air that irritate the lungs.
• Make sure that the baby and other children get all their childhood shots. Doctors now recommend shots to protect against the respiratory syncytial virus.

Caring for a premature infant can be challenging. Parents may experience:

• Emotional pain, including feelings of guilt, anger, and depression
• Anxiety about the baby's future
• A feeling of a lack of control over the situation
• Financial stress
• Problems relating to the baby in the neonatal intensive care unit (NICU)
• Fatigue (tiredness)

Things to do to help during this difficult time include:

• Parents should take careof their own health so that they enough energy to deal with this situation.
• Breast feeding the baby.
• Learning as much as possible about what goes on in the NICU in order to help the baby during his or her stay there and begin to bond with the baby before he or she comes home.
• Learning as much as possible about the baby's condition and what is involved in daily care soin order to ask the right questions and feel more confident about caring for him or her at home.
• Seeking out support from family and friends, as well as hospital personnel. The hospital case manager or social worker can help plan for the baby's needs after leaving the hospital. The social worker also may be able to help in finding a support group in the community.

Chances of Developing Bronchopulmonary Dysplasia

Risk factors

The earlier a baby is born and the lower his or her weight at birth, the greater the chances the baby will develop bronchopulmonary dysplasia (BPD). Most babies who are diagnosed with BPD today weigh less than 3½ pounds, or 1,500 grams, at birth.

About one of every three newborns who weighs less than 2 pounds, or 1,000 grams, at birth gets BPD.

About 5,000 to 10,000 babies born in the United States each year develop BPD. The number of babies who develop BPD is higher than it was 30 years ago because doctors are now able to keep more babies who weigh less than 3 pounds at birth alive.

BPD develops in some babies who have mild or no respiratory distress syndrome. Most of these babies are born at extremely low birth weights or have one of the following conditions:

• Patent ductus arteriosus, a problem in the heart that is present at birth
• Sepsis, a serious bacterial infection in the bloodstream

Clinical Trials

Studies open for recuitment: ClinicalTrials.gov

Expected Outcome

The lungs of the babies who are born with RDS and go on to develop BPD are less developed than those of babies with RDS who recover. They usually have fewer and larger alveoli, or air sacs, than other newborns. They also may have fewer tiny blood vessels in the alveoli. The blood vessels are needed to move oxygen from the alveoli into the bloodstream.

These babies also are more likely than other infants to have problems in other parts of their bodies that aren't yet fully developed. These include the heart, kidneys, brain, stomach, intestines, and eyes.

With new and better treatments now available, most babies with BPD get better over time, and many go on to live normal, active lives.

References

1. ↑ Kallapur SG, Jobe AH. Contribution of inflammation to lung injury and development. Arch Dis Child Fetal Neonatal Ed. 2006 Mar;91(2):F132-5. Abstract Full Text PDF
2. ↑ Rossi UG, Owens CM. The radiology of chronic lung disease in children. Arch Dis Child. 2005 Jun;90(6):601-7. Full Text PDF
3. ↑ Morley CJ, Davis PG, Doyle LW. Nasal CPAP or intubation at birth for very preterm infants. N Engl J Med. 2008 Feb 14;358(7):700-8. Abstract Full Text PDF

Other Resources

• Respiratory Distress Syndrome in Infants
• Lung Information for the Public