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Premature Baby
Premature Baby-Bronchopulmonary Dysplasia
 Babies who are
born prematurely or who experience respiratory problems shortly after birth are
at risk for bronchopulmonary dysplasia (BPD),
sometimes called chronic lung disease. Although most premature babies fully recover from
BPD and have few long-term health problems as a result, BPD can be a serious
condition requiring intensive medical care.
A child is not
born with BPD. It is something that develops as a consequence of prematurity and
progressive lung inflammation.
What Is BPD?
Bronchopulmonary dysplasia involves abnormal development of lung tissue. It is
characterized by inflammation and scarring in the lungs. It develops most often
in a premature baby, who are born with underdeveloped lungs.
"Broncho"
refers to the airways (the bronchial tubes) through which the oxygen we breathe
travels into the lungs. "Pulmonary" refers to the lungs' tiny air sacs (alveoli),
where oxygen and carbon dioxide are exchanged. "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 a premature baby and children. According to the National Heart, Lung, and Blood Institute (NHLBI)
of the National Institutes of Health (NIH), between 5,000 and 10,000 cases of
BPD occur every year in the United States. Premature 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 premature babies eventually outgrow the more serious symptoms, in
rare cases BPD - in combination with other complications of prematurity - can be
fatal.
What Causes BPD?
The majority of
BPD cases occur in a premature baby, usually those who are born at 34 weeks'
gestation or before and weigh less than 4.5 pounds (2,000 grams). These
premature babies
are more likely to be affected by a condition known as infant
respiratory distress syndrome (RDS) or hyaline
membrane disease, which occurs as a result of tissue damage to the
lungs from being on a mechanical ventilator for a significant amount of time.
Mechanical
ventilators do the breathing for a premature baby whose lungs are too immature to allow
them to breathe on their own. The ventilators also supply necessary oxygen to
the lungs of these premature babies. Oxygen is delivered through a tube that
has been inserted into the premature baby's trachea (windpipe) and is
given under pressure from the machine to properly move air into stiff,
underdeveloped lungs. Sometimes, for these premature babies to survive, the amount of
oxygen given must be higher than the oxygen concentration in the air we commonly
breathe.
 Although
mechanical ventilation is essential to their survival, 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. If symptoms of RDS persist, then the condition
will be considered BPD if a premature baby is oxygen dependent at 36 weeks'
postconceptional age.
BPD also can
arise from other adverse conditions that a newborn's fragile lungs have
difficulty coping with, 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 babies
who are premature and have a low birth weight, white male premature babies seem to be at
greater risk for developing BPD, for reasons unknown to doctors. Genetics may
contribute to some cases of BPD as well.
Diagnosis and Treatment of BPD
Important
factors in diagnosing BPD are prematurity, infection, mechanical ventilator
dependence, and oxygen exposure.
 BPD is
typically diagnosed if a premature baby still requires 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.
No available
medical treatment can immediately cure bronchopulmonary dysplasia. Treatment is
geared to support the breathing and oxygen needs of infants with BPD and to
enable them to grow and thrive. Premature babies first diagnosed with BPD receive intense
supportive care in the hospital, usually in a newborn intensive care unit (NICU)
until they are able to breathe well enough on their own without the support of a
mechanical ventilator. Some premature babies also may receive jet ventilation, a
continuous low-pressure ventilation that is used to minimize the lung damage
from ventilation that contributes to BPD. Not all hospitals use this procedure
to treat BPD, but some hospitals with large NICUs do.
Infants with
BPD are also treated with different kinds of medications 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 the
buildup of fluid in the lungs.
Antibiotics are
sometimes needed to fight bacterial infections because babies with BPD are more
likely to develop pneumonia. Part of a premature baby's treatment may involve the
administration of surfactant, a natural lubricant that improves breathing
function. Babies with RDS who have not yet been diagnosed with BPD may have
disrupted surfactant production, so administering natural or synthetic
surfactant may reduce the chance that BPD develops.
In addition,
babies sick enough to be hospitalized with BPD may need feedings of high-calorie
formulas through a gastric tube inserted into the stomach to
ensure they get enough calories and nutrients and start to grow.
 In severe
cases, babies with BPD cannot use their gastrointestinal systems to digest food.
These premature 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 that is 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 NIH estimates that the average length of intensive in-hospital care for
babies with BPD is 120 days. Even after a premature baby leaves the hospital, he or she
may require continued medication, breathing treatments, or even oxygen at home.
Although most children are weaned from supplemental oxygen by the end of their
first year, a few with serious cases may need a ventilator for several years or
even their entire lives (although this is rare).
Improvement for
any baby with BPD is gradual. Some premature babies will be slow to improve; others may
not recover from the condition if their lung disease is very severe. Lungs
continue to grow for 5-7 years, and there can be subtle abnormal lung function
even at school age, although the majority of children function well. Many
premature babies
diagnosed with BPD will recover close to normal lung function, but this takes
time. Scarred, stiffened lung tissue will always have poor function. However, as
infants with BPD grow, new healthy lung tissue can form and grow, and may
eventually take over much of the work of breathing for diseased lung tissue.
Complications of BPD
After coming
through the more critical stages of BPD, some premature babies still have longer-term
complications. They are often more susceptible to respiratory infections such as
influenza, respiratory syncytial virus (RSV), and pneumonia.
When they come down with 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 may also 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. However, this is relatively uncommon and
a late complication.
 Effects of the
medications they may need to take include dehydration and low sodium levels from
diuretics. Kidney stones, hearing problems, and low potassium and calcium levels
can result from long-term furosemide use.
A premature
baby with
BPD often grow more slowly than other babies and have difficulty gaining weight.
They tend to lose weight when they are 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 Child
As with any
child, parents have a critical role in the care of an infant with BPD. One
important precaution you can take is to reduce your premature baby's exposure to
potential respiratory infections. Limit visits from people who are sick, and if
your child needs day care, pick a small center, where there will be less
exposure to infectious agents. Ensuring that your child receives all the
recommended vaccinations can help ward off problems as well. And keep your child
away from tobacco smoke, particularly in your home, as it is a serious
respiratory irritant.
If your
premature baby
requires oxygen at home, your baby's health care providers 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 medication to your premature baby 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 due to breathing problems, you may also
need to feed your baby a high-calorie formula. Sometimes, babies with BPD who
are slower to gain weight will go home from the intensive care nursery on
gastric tube feedings. Formula feedings may be given alone or as a supplement to
breastfeeding.
When to Call Your Child's
Doctor
 Once a
premature baby
comes home from the hospital, parents still need to watch for signs of
respiratory distress or BPD emergencies, instances in which 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
-
wheezing
-
pale, dusky,
or blue skin color that may start around the lips or nail beds
-
trouble
feeding or excess spitting up or vomiting of feedings
If you notice
any of these symptoms in your child, call your child's doctor or seek emergency
medical attention.
Reviewed by:
Michael Spear, M.D.
Clinical
Director, NICU
Medical Director, Infant Apnea Team
Division of Neonatology
Alfred I. duPont Hospital for Children
Wilmington, DE
Clinical Professor of Pediatrics
Jefferson Medical College
Philadelphia, PA
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