interstitial lung disease (ILD)
large number os conditions that involve the parenchyma
-implies inflammatory-fibrotic infiltration of the alveolar walls
pathophysiology of ILD
decreased/low lung compliance
-if the lung is compliant that it is unable to adapt to the environment
restrictive pattern on PFT's (reduced TLC)
reduced diffusion capacity
hypoxemia- initially with exercise, later at rest
if someone has obstructive and restrictive how would that be described?
a reduced FEV-1% and a reduced TLC
ex- coal miners lung
What are the results on PFT for restrictive?
FEV-1 - decreased
FVC - decreased
FEV-1%- normal or increased
TLC - decreased
FRC - decreased
What are the results on PFT for obstructive?
FEV-1 - decreased
FVC - normal or decreased
TLC - normal
FRC - normal or increased
Characteristics of obstructive:
normal or elastic lungs
normal or low elastic recoil
high airway resistance
low expiratory flow rates
Characteristics of restrictive:
high elastic recoil
normal airway resistance
high expiratory flow rates
what is the clinical presentation os ILD?
dyspnea on exertion, non-productive cough
tachypnea, bibasilar inspiratory dray crackles
may have: clubbing, cyanosis, signs of cor pulmonale
how to dx ILD
PE, CXR, PFT's, 6-min walk test, HRCT
What is more useful for diagnosing ILD? CXR or HRCT/
CXR is no sensitive enough, they can have what appears to be normal or, alveolar filling, reticular/nodular pattern
HRCT gives you a good look at parenchyma , allowing you to inspect for fibrosis, honeycombing, ground glass infiltrates, nodules
What is idopathic pulmonary fibrosis/ usual interstitial pneumonitis (UIP)?
rare, causes fibrosis/scarring- prototype ILD
-symptoms have insidious onset but steadily progress, usually in middle aged-elderly
-more common in males
cause is unknown, associated with smoking
what do the labs show/dx/tx in UIP?
HRCT- peripheral/subpleural abnormalities, lower lobes, honeycomb, cysts
dx- sx biopsy
no proven treatment
what is sarcoidosis w/lofgrens syndrome?
erythema nodosum: raised swollen nodules
bilateral hiliar adenopathy (BHA)
what is sarcoidosis?
-characterized by development of non-caseating granulomas in one or more organs
-cause is unknown, but may be form of hypersensitivity reaction
-typically occurs in young females, balacks
-may involve any organ (resp more common)
what are lab studies for sarcoid
skin tests for allergies
elevated ACE levels
how is sarcoidosis dx?
-biopsies of affected organ that is demonstrating non-caseating granulomas
-must exclude other granulomatous diseases
-increased CD4/CD8 ratio
what does a CXR for sacroidosis look like?
-upper/mid lung zone predominance
distortion and fibrosis
sarcoidosis signs associated with worse prognosis
higher CXR stage at initial diagnosis
onset >40 y/o
longer duration of symptoms (>6 months)
absence of E. nodosum (Lofgren's syndorme)
involvement of more than 3 organ systems
what are some tx's for sarcoid?
1st line- corticosteroids with a slow taper
2nd line- anti-inflammatory/cyctotoxic agents
what are definite indications for tx of sarcoid?
cardiac, eye, CNA, symptomatic hypercalcemia, symptomatic lung disease with decreasing PFT, extensive skin lesions
establishing hx of asbestos exposure and pleuropulmonary manifestation is key
-occupation commonly associated w/ exposure
what are some manifestations of asbestos?
benign asbestos pleural effusion
what is "asbestosis"?
ILD with onset 20 years or more after exposure
-no specific/effective therapy
no role for corticosteroids
what is mesothelioma
highly fatal malignancy occurring 30-40 years after onset of asbestos exposure
- no effective therapy
-unrelated to pleural plaques. CA of pleura of the lungs
what is hypersensitivity pneumonitis?
extrinsic allergic alveolitis
-immune disease of lung due to repeated/prolonged exposure to variety of organic dusts in a susceptible individual
-pathology=mononuclear cell infiltration/ loosely formed granulomas (no biopsy needed)
-CXR=reticulo-nodular, infiltrates (may normalize between episodes)
explain acute hypersensitivity pneumonitis?
repeated episodes of acute "pneumonia"- cough, fever, chills, dyspnea, crackles, interstitial lung pattern
explain chronic hypersensitivity pneumonitis?
very slow progressive with chronic interstitial abnormalities on chest x-ray
what are the common antigens of hypersensitivity pneumonitis?
farmer's lung (thermophilic actinomycetes)
bird-fancier's lung (avian proteins)
many agricultural sources reported