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Medical
Care
There are
many components to treating A1AD. These include smoking cessation,
asthma medications (if necessary), infection control, good nutrition and
exercise. Preventing or slowing the progression of lung disease is
the major goal of AAT deficiency management. Facilitate this goal by
decreasing any proinflammatory stimuli in the alveolus, including
smoking, asthma, or respiratory infection. Alternatively, augmenting or
replacing the deficient enzyme, and thereby moderating inflammatory
stimuli, is possible. Most patients are identified only after they
develop lung disease, and the goals of treating AAT deficiency emphysema
are similar to those for treating all forms of emphysema.
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Quitting smoking
No treatment for emphysema has a greater effect on survival than
quitting smoking. Make a concerted effort to inform patients about
the serious consequences of smoking on AAT deficiency and provide
them with one of the many aids to help them quit. Most patients with AAT
deficiency quit successfully. Remember the
4 stages in the process of helping patients become nonsmokers:
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1)
ask about smoking habits
2) advise about health effects
3)
assist the patient with encouragement, education, and nicotine
replacement
4) arrange follow-up
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Improving lung
function
Provide similar efforts to improve lung function
in patients with AAT deficiency emphysema as those provided to
patients with emphysema from the usual causes. Administer
beta-adrenergic agents and ipratropium bromide bronchodilators to
maximize lung function. Metered-dose inhalers are the preferred
method of administration because they have a lower incidence of
adverse effects than other routes. No matter how they are
administered, no evidence indicates that these drugs have any
long-term effect on disease progression. Theophylline may
lessen the degree of dyspnea in some individuals, and a therapeutic
trial may be indicated for selected patients. The therapeutic range
of theophylline is relatively small, and its metabolism frequently
is altered by other drugs or illness, which can lead to frequent
episodes of drug toxicity or the need for frequent monitoring of
serum levels. Inhaled corticosteroids have not been studied in
patients with AAT deficiency emphysema, but many patients have
significant broncho-reactivity and, in this group, inhaled steroids
probably help control symptoms. Reserve oral corticosteroids
for acute exacerbations with increased cough and sputum. Long-term
administration of corticosteroids does not protect the lung from
progressive emphysema, but it is associated with a long list of
detrimental adverse effects. Limit their use to brief courses
lasting 1-2 weeks. Institute therapy to prevent osteoporosis when
administering longer courses.
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Preventing
respiratory infections
Pneumonia and annual influenza
vaccines will help prevent respiratory infections.
Aggressively treating infections that occur despite prophylaxis may
help decrease the potential for additional lung injury from an
influx of neutrophils into the alveolus.
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Pulmonary
rehabilitation
According to a National Institutes of
Health (NIH) workshop, pulmonary rehabilitation is defined as
"a multi-disciplinary continuum of services directed to persons
with pulmonary disease and their families, usually by an
interdisciplinary team of specialists, with the goal of achieving
and maintaining the individual's maximum level of independence and
function in the community." Most programs combine
education, exercise conditioning, breathing training, chest physical
therapy, and respiratory muscle training with nutritional counseling
and psychological support. Therapy does not improve pulmonary
function test results, but well-controlled studies documented
significant improvement in exercise endurance, exercise work
capacity, level of dyspnea, quality of life, and reducing
health-related expenses.
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Reducing hypoxemia
Hypoxemia accelerates mortality in patients with severe airflow
obstruction, and oxygen supplementation prolongs survival for this
group. Oxygen also increases exercise capacity, improves
mental performance, decreases dyspnea with exercise, and improves
sleep quality. Stable patients with resting hypoxia benefit
most if they wear their oxygen mask continuously. The benefits for
patients with hypoxemia only during exercise or sleep are not as
clear, and oxygen may be prescribed for those intervals when the
oxygen saturation is likely to be low.
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Replacing enzymes
AAT-deficient individuals who have or show signs of developing
significant emphysema can be treated with Prolastin, a pooled,
purified, human plasma protein concentrate replacement for the
missing enzyme that has been screened for HIV and hepatitis viruses.
It also is heat-treated as an additional precaution against
transmission of infection. Immunize patients against hepatitis
regardless. Weekly intravenous infusions of PROLASTIN,
ARALAST,
KAMADA, or ZEMAIRA
restore serum and alveolar AAT concentrations
to protective levels.
Although other regimens for administration have proven to provide
similar serum levels, only the weekly infusion schedule has US Food
and Drug Administration approval. No controlled studies have
proven that intravenous augmentation therapy improves survival or
slows the rate of emphysema progression. Results from the NIH
patient registry and a comparison of Danish and German registries
have been published, and both suggest that augmentation therapy has
beneficial effects. Although they were not controlled treatment
trials, the similarity of the results suggests that the findings are
significant. The NIH report described an overall death rate
1.5 times higher for those who did not receive augmentation therapy
and a rate of FEV1 decline (54 mL/y) in AAT-deficient
individuals approximately twice that of healthy nonsmokers but
approximately 50% that of smokers (108 mL/y). Prolastin treatment
did not improve the average FEV1 decline (54 mL/y);
however, participants with moderate airflow obstruction (FEV1 35-49% of predicted value) experienced a slower rate of decline
(mean difference 27 mL/y). These findings bolster the long-held
belief that augmentation therapy provides clinical benefit. No firm
guidelines have been developed for initiating or continuing
augmentation therapy. Most pulmonary physicians require the
serum level to be below the threshold protective value and that the
patient have 1 or more of the following: signs of significant lung
disease such as chronic productive cough or unusual frequency of
lower respiratory infection, airflow obstruction, accelerated
decline of FEV1, or chest radiograph or CT scan evidence
of emphysema. The American Thoracic Society recommends
starting treatment when the FEV1 is less than 80% of the
patient's predicted value.
Surgical
Care
Two surgical approaches may help selected
patients with AAT deficiency.
- Volume reduction surgery Also
known as an LVRS (Lung Volume Reduction Surgery) is a procedure that
has generated nationwide interest and hope for patients with all
types of emphysema. Selected patients with severe emphysema
and significant air trapping have experienced symptomatic
improvement by removing the most severely affected 20-35% of each
lung. Spirometry and exercise tolerance generally improve following
postoperative recovery. Dyspnea generally is diminished. The effects
on blood gas values are variable. Some of the enthusiasm for
the procedure has waned, even as surgical mortality rates have
diminished, because the duration of improvement seems to be brief;
an accelerated rate of FEV1 decline appears to occur
after the surgery. A randomized controlled trial (National
Emphysema Treatment Trial) currently is recruiting patients at 17
medical centers around the country to clarify the benefits and risks
associated with the surgery. Because experience is limited,
whether AAT deficiency emphysema patients fare better or worse with
this surgery is unknown.
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- Lung transplantation
Transplantation is the second surgical option for patients with
severe AAT emphysema. If patients are at substantial risk of
early mortality and are otherwise healthy, they may be candidates
for lung transplantation. Contact a local transplant center
before patients become too ill (cachexia, inactivity, frequent
infections). Unfortunately, the average waiting time for a
transplant in the United States is 18-24 months, and the
uncertainties of emphysema exacerbations and complications that
might prevent transplantation make it imperative that patients be
referred well in advance of need. Offer patients with an FEV1
less than 35% of predicted value (5-y mortality rate of 50%),
especially men or individuals with substantial broncho-reactivity,
the opportunity to discuss the option with a transplant physician.
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- Liver Transplantation In rare
instances where the disease progresses to liver failure, liver
transplantation is the only effective treatment at this time. (2)
The diagnosis of AAT deficiency emphysema
is not difficult, but most physicians will have no experience treating a
patient, providing counseling, or answering the questions that an
uncommon hereditary disorder generates. Several visits with a specialist
in the first year usually are enough to meet a patient's needs. The
Alpha-1 National Association, 1-800-4ALPHA-1, http://www.alpha1.org/
can facilitate locating physicians with interest and experience in
caring for these patients.
Dietary
Care
Patients with advanced
chronic obstructive lung disease are characterized by a significant
reduction in fat-free muscle mass. This pulmonary cachexia is common in
patients with AAT deficiency and is associated with a decline in
clinical status. The syndrome is a result of multiple factors, including
hypermetabolism, drug therapy, inactivity, and aging. Prolonged
glucocorticoid administration accelerates the process. Protein-calorie
supplementation as one component of a comprehensive treatment program
may reverse the loss of muscle mass, and dietary counseling may aid
patients at high nutritional risk. Providing more fat-based nonprotein
calories may benefit patients with respiratory failure who are on
mechanical ventilation, but, other than this special circumstance,
little evidence exists to suggest that this dietary manipulation aids
ambulatory patients.(1)
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