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In Depth Tutorials and Information
CHAPTER
35
Pulmonary Function in Osteogenesis
Imperfecta
Robert A. Sandhaus
National Jewish Health and the University of Colorado, Denver, CO, USA
INTRODUCTION
adults with OI? How much risk do certain respiratory
mechanical therapies involve when applied to OI? Can
a percussive vest be used for secretion clearance? Can
one do chest physical therapy that involves pounding
on the chest wall? Does induction of cough for sputum
clearance put an OI patient at greater risk of rib or even
vertebral fractures? Some of these questions have simple
answers, some do not. This chapter will summarize what
we know about lung disease in OI, suggest ways to diag-
nose and follow such disease, and point to what we need
to learn in the future. At the time of this writing, there
are no clinical guidelines for the management of lung
disease in OI, therefore any treatment recommendations
should be tempered with personal clinical experience
and judgment.
The lungs, chest cavity and respiratory muscles are
designed to accomplish one primary purpose: to put the
outside world in intimate contact with the blood supply.
There's enough redundancy in the pulmonary structures
of the normal lung that if an entire lung must be removed
from an otherwise healthy individual, there is often
little or no change in lung function and gas exchange.
However, conditions that affect the lung parenchyma,
the airways or the bellows mechanism of the chest can be
among our most devastating chronic diseases.
People with OI are at risk of a variety of pulmonary
conditions. Rather than being an incidental inconvenience
in a disease that primarily affects the bones, pulmonary
diseases limit the quality and length of life in many OI
patients. Most important, pulmonary diseases are a
major cause of death in OI.
1
From pulmonary hypopla-
sia in severe OI causing intrauterine or neonatal death, to
restrictive disease caused by the chest wall or pulmonary
collagen abnormality, airway obstruction, pulmonary
hypertension and sleep apnea, the lungs can be greatly
affected in OI.
2-5
Usual methods of evaluating lung disease are more
difficult in people with OI. Chest radiology, whether
plain films or computed tomography (CT), can be dif-
ficult to interpret, especially for those who see few such
patients. Pulmonary function testing presents unique dif-
ficulties especially in the setting of OI resulting in short
stature. Even sleep studies present unique challenges
when sleep labs are not experienced at providing sleep
environments for patients with anatomic distortions.
Finally, therapy can provide unusual challenges.
Should medication doses be adjusted in children or
SEVER
ITY OF OI AND LUNG DIS
EASE
There is a relationship between the severity of OI and
the risk of lung disease.
1,6
If this were not true, then it
would not have taken so long to appreciate the subtle
pulmonary parenchymal abnormalities in those with
type I OI.
5
The most severe forms of OI, those that result
in fetal or neonatal death, tend to be accompanied by the
most dramatic chest wall architectural abnormalities and
the most dramatic intrinsic pulmonary problems, such as
pulmonary hypoplasia.
3
For most clinicians caring for patients with OI the pri-
mary pulmonary concern is the restriction of air move-
ment caused by chest wall abnormalities. The chest wall
architecture can be affected by kyphoscoliosis, vertebral
collapse, rib fractures, pectus carinatum and limitation
of diaphragmatic movement by abdominal contents
