pulminary fibrosis
Idiopathic Pulmonary Fibrosis (IPF) is a disease of
inflammation that results in scarring, or fibrosis, of the lungs. In time, this
fibrosis can build up to the point where the lungs are unable to provide oxygen
to the tissues of the body.
Doctors use the word "idiopathic" (from the Greek "idio" meaning "peculiar"
or "unusual" and "pathy" meaning "illness") to describe the disease, because the
cause of IPF is unknown. Currently, researchers believe that IPF may result from
either an autoimmune disorder, a condition in which the body's immune system
attacks its own tissues, or the after effects of an infection, most likely a
virus.
Whatever the trigger is for IPF, it appears to set off a series of events in
which the inflammation and immune activity in the lungs--and, eventually, the
fibrosis processes, too--become uncontrollable. In a few cases, heredity appears
to play a part, possibly making some individuals more likely than others to get
IPF.
In studies of patients with IPF, the average survival rate has been found to
be 4 to 6 years after diagnosis. Those who develop IPF at a young age seem to
have a longer survival.
The exact
number of people who develop IPF each year is not known. It is known, however,
that equal numbers of men and women get the illness and that most cases of IPF
are diagnosed when the patients are between the ages of 40 and 70.
Early symptoms of IPF are usually similar to those of other
lung diseases. Very often, for example, patients suffer from a dry cough and
dyspnea (shortness of breath). As the disease progresses, dyspnea becomes the
major problem. Day-to-day activities such as climbing stairs, walking short
distances, dressing, and even talking on the phone and eating become more
difficult and sometimes nearly impossible. Enlargement (clubbing) of the
fingertips may develop. The patient may also become less able to fight
infection. In advanced stages of the illness, the patient may need oxygen all
the time.
IPF can lead to death. Often the immediate cause is respiratory failure due
to hypoxemia, right-heart failure, a heart attack, blood clot (embolism) in the
lungs, stroke, or lung infection brought on by the disease.
Although the course of IPF varies greatly from person to
person, the disease usually develops slowly, sometimes over years.
The early stages are marked by alveolitis, an inflammation of the air sacs
called alveoli, in the lungs. The job of the air sacs is to allow the transfer
of oxygen from the lungs into the blood and the elimination of carbon dioxide
from the lungs and out of the body.
As IPF progresses, the alveoli become damaged and scarred, thus stiffening
the lungs. The stiffening makes breathing difficult and brings on a feeling of
breathlessness (dyspnea), especially during activities that require extra
effort.
In addition, scarring of the alveoli reduces the ability of the lungs to
transfer oxygen. The resulting lack of oxygen in the blood (hypoxemia) may cause
increases in the pressure inside the blood vessels of the lungs, a situation
known as pulmonary hypertension. The high blood pressure in the lungs then puts
a strain on the right ventricle, the lower right side of the heart, which pumps
the oxygen-poor blood into the lungs.
The
first suspicion that a person may have IPF is usually based on the patient's
symptoms and medical history. The doctor will try to confirm or rule out any
suspicion by ordering one or more of the following tests:
- Chest X ray
- A simple chest X ray is a picture of the lungs and surrounding tissues,
most often taken while the patient is standing up. In an IPF patient, the X
ray usually reveals shadows, mostly in the lower part of the lungs. In
addition, lung size tends to appear smaller than normal.
- Computed Tomography (CT)
- A computed tomography scan of the chest is a series of X rays that
provide a view of the lungs that looks almost as if a slice had been made
through the chest. During a CT scan, the patient lies inside a long,
oval-shaped machine that permits x-ray beams to pass through the top, sides,
and back of the body. A computer is used to combine all the pictures taken
from these positions and thus gives the doctor a good look at what's going
on inside the lungs and chest.
- Blood Tests
- When IPF is suspected, the doctor will analyze the patient's blood. A
low level of oxygen in the arterial blood may reveal that the alveoli are
not taking up enough oxygen.
- Pulmonary Function Tests
- Pulmonary function tests (PFTs) require the patient to breathe into a
mouthpiece. The mouthpiece, in turn, is connected to a machine that measures
the amount of air the patient breathes in and out over a specific period of
time. The results tell the doctor how well the air passages in the lungs are
functioning and how well the lungs are expanding.
- Bronchoalveolar Lavage
- Lung washings (bronchoalveolar lavage) are also helpful in arriving at a
diagnosis of IPF. In this procedure, the doctor inserts a long, narrow,
flexible, lighted tube called a bronchoscope down the windpipe and into the
lungs to remove fluid (lavage) and other materials from inside the lungs.
The amounts of certain cells and proteins found in the materials are
measured to determine the stage of the lung disease.
Even is some or all of the results from such tests are abnormal, they are
rarely sufficient to make a specific diagnosis of IPF. The only way the
doctor can confirm a diagnosis of IPF is by examining the lung tissue; such
tissue is usually obtained by an open lung biopsy.
- Open Lung Biopsy
- In an open lung biopsy, a chest surgeon makes cuts between the ribs in
the chest and removes small pieces of tissue from several places in the
lungs. The material is examined in the laboratory to determine how much
inflammation and fibrosis are in the lungs. It is the only way to confirm
whether the patient has IPF. If IPF is present, the biopsy results are also
the best way to find out how far the disease has progressed and what the
outlook is. In a patient with no other significant illness, recovery from an
open lung biopsy is relatively quick. The hospital stay is usually 4 to 7
days; some newer procedures require less surgery, bringing hospital stays to
1 to 3 days.
The
best chance of slowing the progress of IPF is by treatment as soon as possible.
Most IPF patients require treatment throughout life, usually under the guidance
of a lung specialist. Some major medical centers and large teaching hospitals do
research on the disease and provide consultation and treatment to patients.
Treatment for IPF may vary a great deal. It depends on many things, including
the age of the patient and stage of the disease. The aim of treatment is to
reduce the inflammation of the alveoli and stop the abnormal process that ends
in fibrosis. Once scar tissue has formed in the lung, it cannot be returned to
normal.
Drugs are the primary way that IPF is treated. They are
usually prescribed for at least 3 to 6 months. This gives the doctor time to see
if a particular treatment is effective. A combination of tests is used to
monitor how well a particular drug is working. The dose may have to be adjusted
so that the medicine gives the best possible results with the least side
effects. Most side effects are reduced when the dose is made smaller or the drug
is stopped. Commonly used drugs are prednisone and cytoxan. Oxygen
administration and, in special cases, transplantation of the lung are other
choices.
- Prednisone
- A corticosteroid, prednisone, is the most common drug given to patients
with IPF. About 25 to 35 percent of all patients respond favorably to this
medicine. No one knows exactly how corticosteroids work or why some patients
do well on prednisone while others do not. Patients take prednisone by mouth
every morning, starting with a high dose for the first 4 to 8 weeks. As they
improve, they gradually take smaller amounts. Changes in mood are one of the
more common side effects of prednisone; most patients, however, can handle
the mood changes--anxiety, depression, or sleeplessness--once they know what
is causing the problem. A less common side effect is a rise in blood-sugar
levels.
- Cytoxan
- Cyclophosphamide, also referred to as cytoxan, may be taken together
with prednisone, or instead of it. Like prednisone, cytoxan is swallowed
each day. One of the more serious side effects of cyclophosphamide is
leukopenia, a condition in which the number of white blood cells drops to a
dangerously low level. Leukopenia can be controlled by regularly checking
the blood count and adjusting the dose of cytoxan if
necessary.
- Other Medicines
- Azathioprine, penicillamine, chlorambucil, vincristine sulfate, and
colchicine have been used in a few patients with IPF. Their effectiveness in
treating IPF, however, has not been adequately tested.
- Oxygen
- In addition to treatment with medicine, some patients may need oxygen,
especially when blood oxygen becomes low. This treatment helps resupply the
blood with oxygen. As a result, breathlessness is reduced, the patient can
be more active, and the severity of pulmonary hypertension
decreases.
- Exercise
- Regular exercise may be useful for patients with IPF. A daily walk or
regular use of a stationary bicycle or treadmill can improve muscle strength
and breathing ability and also increase overall strength. If needed,
supplemental oxygen should be used; sometimes it is the only way a patient
is able to do a reasonable amount of activity.
- Lung Transplantation
- Lung transplantation, either of both lungs or only one, is an
alternative to drug treatment for patients in the severe, final stages of
IPF. It is most often performed in patients under 60 years of age who do not
respond to any form of treatment. The 1-year survival rate is approximately
60 percent.
Many IPF patients, particularly those in the early
stages of the disease, respond to drug treatment and can continue to go about
most of their normal activities, including working. Some patients with advanced
IPF need to carry oxygen with them.
In addition to getting proper treatment, IPF patients can help themselves by
following the same sensible health measures that everyone should observe. These
include eating a healthy diet, maintaining proper weight, exercising regularly,
and getting enough rest. Above all, IPF patients should not smoke. Pregnancy is
not advisable because the illness puts an extra load on the heart and lungs.
As with many chronic illnesses, emotional support and psychological
counseling can be of much help to the patient. Most doctors and patients agree
that it is important for both patient and family to be as informed as possible
about IPF. In this way, everyone involved can understand the illness and apply
that information to what is happening in his or her own life.
Keeping on Top of Your Condition
Keeping in tune with your disease or condition not only makes treatment less intimidating but also increases its chance of success, and has been shown to lower a patients risk of complications. As well, as an informed patient, you are better able to discuss your condition and treatment options with your physician.
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