Restrictive and Interstitial
Lung Disease
J.B. Handler, M.D.
Physician Assistant Program
University of New England
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Abbreviations
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SLE- systemic lupus
erythematosis
DLCO- diffusing capacity
for carbon monoxide
HRCT- high resolution
computed tomography
ALS- Amyotrophic Lateral
Sclerosis
RR- respiratory rate
IFIP- idiopathic fibrosing
interstitial pneumonia
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RA- rheumatoid arthritis
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Restrictive Disease and
Dysfunction
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Collection of diseases that are
characterized by reduction in volume
of air within the lung parenchyma.
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Abnormal reduction in pulmonary ventilation.
Restrictive pattern on PFT’s.
Compensated by RR.
Multiple etiologies: Most common are
forms of interstitial lung disease.
Some diseases have both obstructive and
restrictive components: Cystic fibrosis,
others.
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Interstitial Lung Disease
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Heterogeneous group of diseases (>180)
with common response to lung injury.
Idiopathic fibrosing interstitial
pneumonia (IFIP), formerly called
Idiopathic (primary) Pulmonary
Fibrosis: Classic example of restrictive
lung disease.
Multiple secondary etiologies- see below.
Pathology is similar, regardless of
etiology.
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Secondary Etiologies
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Drug related: Amiodarone (potent antiarrhythmic), bleomycin (tx cancer), some
antibiotics (sulfonamides), others.
Occupational inhalation: Silica, asbestos,
beryllium, others.
Connective tissue disorders: SLE,
Polymyositis, RA, scleroderma.
Others: Radiation, amyloidosis,
sarcoidosis.
Infections: Fungal (Coccoidiomycosis,
Pneumocystis), Mycobacterium, some
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viruses.
IFIP
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Diagnosis of exclusion
Must exclude other etiologies (via
biopsy) before saying “idiopathic”.
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Variations of IFIP exist, with varying response
to therapy.
Characteristic clinical, radiographic, PFT
and other findings.
Poor prognosis as with many other
etiologies of interstitial lung disease.
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Pathology
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Inflammatory infiltrate in lung
parenchyma/interstitium:
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Inflammation of alveolar epithelium and
capillary endothelium followed by:
Fibrosis of the alveoli and interalveolar
septum
Inflammation can include the respiratory
bronchioles.
Thickening of alveolar-capillary
membrane by collagen and fibrous tissue.
Over timeFibrosis throughout lung
parenchyma.
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Terminal Respiratory Unit
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Pathology/Pathophysiology
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Inflammatory cellular and fibrotic
response.
Inflammatory cells release chemical
mediators activation of fibroblasts
collagen deposition.
Tissue injury, vascular injury and
permeability.
Epithelial injury thickens/breaks alveolarcapillary membraneimpaired diffusion
of gas (DLCO).
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Pathophysiology
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Destruction of alveoli/capillariesV/Q
mismatch; both shunting and increased
dead space.
Ongoing repair/re-injury cycle; nonhomogeneous scarring throughout lung.
Lung compliance.
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Normal Lung Parenchyma
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Pulmonary Fibrosis
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Clinical Presentation (IFIP)
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Insidious onset most often with gradual
development of shortness of breath;
initially exertional, then at rest.
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Other etiologies may have acutechronic
presentation.
History: Occupational exposure? Smoker?
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Travel history (parasitic infections)
Risk factors for HIV
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Clinical Presentation
Decreased activity tolerance
 Dry, non-productive cough
 +/- fever; depends on etiology
 Presentation may vary depending on
etiology
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Physical Exam, Testing
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Lungs: Fine, inspiratory crackles (like
velcro) at lung bases. RR late.
Clubbing of fingers: bony growth and
enlargement of terminal phalange;
present 25-50% of cases.
Chest x-ray (see below): May appear
normal until advanced disease.
HRCT- may be useful- confirms “honeycomb pattern”.
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Clubbing of Fingers
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Chest X-Ray
Lung volume
Interstitial
“honeycombing”
Indicates advanced
Disease
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PFT’s and ABG
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Marked reduction in all lung volumes.
FVC, FEV1, both often markedly
Normal FEV1/FVC (or )
DLCO
ABG: progressive hypoxemia due to
both DLCO and V/Q mismatch. Worse
with exercise. PCO2 reflects increased
respiratory rate to accommodate
hypoxemia. PCO2 levels rare except with
end stage disease.
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Lung Biopsy
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Most important tool to confirm
diagnosis and sort out underlying
etiologies.
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Trans bronchial biopsy- least invasive, but
sample size to small in most cases.
Thoracoscopic biopsy- less invasive than open
thoracotomy but still requires small incisions
into thorax.
Open lung biopsy- requires thoracotomy;
multiple samples obtained from different
areas of lung.
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Treatment
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No data to show that any treatment
improves survival or quality of life of in
patients with IFIP. Progressive disease in
most patientsdeath in 3-5 years.
Other etiologies sometimes respond to
systemic corticosteroids (prednisone, et
al) or immunosuppressive agents with
varying degrees of improvement.
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Restrictive Disease: Others
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Neuromuscular diseases: ALS, Muscular
Dystrophy, Polio,etc.
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Impair lung inflation; restrictive pattern on
PFT’s.
Kyphoscoliosis: Decrease lung volume;
restrictive pattern on PFT’s. – abnl
forward bending puts pressure on lungs
Pleural diseases: prevent lung expansion;
restrictive pattern on PFT’s.
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Scoliosis
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