what-when-how
In Depth Tutorials and Information
hand or using an electrical or pneumatic device, since
effective therapy usually requires force that is likely
to put an OI patient at risk of bony fractures of the ribs
and vertebrae. The other methods mentioned, however,
are likely to provide benefit with minimal risk if used
appropriately.
It is often useful to start with simple inhalers, nebu-
lized medication or a flutter system, if secretion clearance
becomes a problem. These can be used in combination,
depending on the setting and the patient's response.
Pneumatic vests are designed for easy adjustment
of frequency and force of the vibrations. Although spe-
cial attention is needed when using these vests, they
may provide benefit in those who have failed other
approaches. The vests themselves come in such a wide
variety of sizes and configurations that it may be possi-
ble to it even very deformed chests.
IPPB is an older form of therapy that has contin-
ued to be used in non-OI patients to improve ventila-
tion in lungs restricted by chest wall deformity such as
severe kyphoscoliosis.
15,16
However, it has not been well
studied in OI. One might be concerned that the pres-
sure pushing air into the lungs could be as potentially
harmful as someone pounding on the lungs from the
outside of the chest wall, but the pressure rapidly dis-
sipates as air passes from larger airways to smaller and
smaller airways. If treatment is monitored carefully and
pressures are only gradually increased as tolerated, this
type of therapy can open airways that have closed over
time and increase ventilation to poorly ventilated areas
of the lung. These improvements often persist between
treatments.
A newer technique, similar to IPPB and with some
use in OI, is IPV.
17
This is a mechanical device that
delivers rapid, small volume bursts of air during the
inhalation and exhalation cycle via a mouthpiece. IPV
has been used successfully in cystic fibrosis and bron-
chiectasis. Its use in OI is being evaluated.
In patients with COPD and asthma, therapies are
well established and guidelines exist (and are fre-
quently updated). The mainstay of childhood therapy
for asthma and adult therapy for COPD is a graded and
stepwise approach based on response to therapy and
severity of obstruction.
Inhaled steroids are the first-line therapy for asthma
in those without OI, although newer data have sug-
gested this approach is not as benign as initially
thought, with loss of bone density, growth delay and
increased risk of pneumonia being suggested by recent
trials.
18
Since one of the major side effects of all gluco-
corticoid steroids, whether taken by mouth or inhala-
tion, is loss of bone density, these medications should
be considered quite carefully in patients with OI. Long
acting inhaled bronchodilators and anticholinergics are
likely better choices.
Exacerbations due to infection should be treated rap-
idly and aggressively but with an eye toward preventing
the appearance of resistant microorganisms. This means
obtaining a sputum culture, if possible, prior to start-
ing empiric therapy and rapidly changing to therapy
directed by results of the culture when available. For
those individuals with chronic colonization by resistant
organisms such as pseudomonas, it can be useful to treat
with multiple antibiotics based on culture sensitivity
results when the organism numbers and symptoms start
to increase. Such a “tune-up” can prevent more serious
infections down the line.
In stable OI patients, annual lung function testing
and chest X-ray along with room air oximetry can detect
problems before they cause symptoms. In people with
known chronic hypoxemia, an arterial blood gas may
need to be substituted for oximetry in order to evaluate
for carbon dioxide retention. A complete blood count
(CBC) can evaluate for elevated (suggesting chronic
hypoxemia) or decreased (suggesting anemia) red blood
cell numbers or hemoglobin.
In patients with chronic hypoxemia, supplemen-
tal oxygen, whether with sleep, with exercise or 24
hours a day, depending on the need, can be lifesaving.
Appropriate administration of supplemental oxygen can
allow OI patients to continue their exercise programs,
sleep better, prevent or treat cor pulmonale and gener-
ally improve function and mentation. In general, oxygen
saturations of less than 88% are considered appropriate
for treatment with supplemental oxygen. During exer-
cise, short dips into saturations below 88% can be toler-
ated well without oxygen therapy, but longer periods of
hypoxemia during exercise should not be tolerated.
Obstructive sleep apnea is most often treated with a
continuous positive airway pressure (CPAP) device, usu-
ally delivering air through a nasal mask or face mask
during sleep. While uncomfortable initially, newer CPAP
machines and masks have improved the tolerability
of such treatment. There are variations on this type of
therapy like BiPAP which provided different pressures
during inhalation and exhalation that may improve
ventilation, depending on the patient. Under extreme
circumstances, severe OSA can be treated with tracheos-
tomy and nocturnal ventilation.
REVIEW OF RECENT LITERATURE AND
THE F
UTURE OF LUNG DISEASE
IN OI
Recent literature includes a compelling review of
both the molecular biology and clinical aspects of OI by
Forlino and colleagues.
19
While the importance of pul-
monary infection and restriction is discussed and the
importance of cardiopulmonary disease as a cause of
morbidity and mortality is emphasized, the primary
