Restrictive Lung Disease Flashcards
Main Points
Restrictive Lung Diseases cause a decrease lung volume
Can be caused by extrinsic or intrinsic factors
DLCO in Restrictive Lung Disease
Early–can’t transport oxygen from air to alveoli to blood causes hypoxemia
Late–Can’t transport carbon dioxide from blood to alveoli to air causing carbon dioxide retention
Extrinsic causes of restrictive lung disease
Neuromuscular disorders (myasthenia gravis, Guillan Barre, ALS, polio)
Disorders of the chest wall (musculoskeletal deformities, obesity (Pickwickian Syndrome))
Pleural thickening
Intrinsic Restrict Lung Disease Synonyms
Interstitial Lung Disease
ILD
DIffuse parenchymal lung disease
DPLD
Fibrotic lung disease
Intrinsic Restrive Lung Disease Classification
Characteristics:
- diffuse lung injury
- inflammation
- progresses to irreversible fibrosis
- severely compromised gas exchange
Classification based on location
- Bronchiolities
- Alveolitis
- Vasculitis
- Combination
Classification may be baed on etiology
Example Etiologies of ILD
Environmental and occupational exposure
hypersensitivity
idiopathic
drug induced
radiation
Epidemiology of ILD
Relatively Uncommon
Onset and mortality varies depending on underlying etiology
Restrictive pattern on PFTs of ILD
Reduced FVC
Reduced FEV1
Normal FEV1/FVC
Pathophysiology of ILD
Decreased dispensability of lung. VC and TLC decrease as lung becomes stiffer
Loss of capillary and alveolar surface area–hypoxemia and respiratory alkalosis
V/Q mismatch
Hypoxemia: early with exercise, later at rest
Tachypnea is common
Hypercapnea is common only in severe or terminal cases
Pulmonary HTN in late cases
Disortation of airways may cause obstruction in advanced cases
Correlation between sxs, radiographic abnormalities, and physiologic abnormalities is poor
Symptoms of ILD
cough
dyspnea
Physical Findings of ILD (general)
Tachypnea
Tachycardia
Low O2 sat
Lungs: rales or wheezes
Heart: may have signs of right sided heart failure in severe cases
clubbing
Diagnosis of ILD
History
- Onset may be insidious, subacute with relapsing and remitting course or may be fulminant
**Physical **
**Testing **
- PFT
- Associated labs for underlying disease
- CXR: diffuse lung disease
**Lung Biopsy **
- Thoracoscopy
- Open lung biopsy
Idiopathic Pulmonary Fiborsis
Progressive disease of unknown original resulting in pulmonary fibrosis
Generally put into 4 categories
Most pts progress to end stage fibrosis and die
Time course and prognosis depends on category
Pneumoconiosis
Coal minors lung, abestosis, silcosis
PE: normal; crackles; clubbing
CXR: diffuse reticulonodular infiltrates, eggshell calcifications of hilar nodes
Lab: nonspecific
Fibrosis: different types depending on agent exposed to
Hypersensitivity pneumonitis
Extrinsic allergic alveolitis
Immunologically mediated disease from repeated inhalation and sensitization to organic dusts
Acute (cough, fever, chills, and malaise last 18-24hrs), subacute and chronic forms (constant exposure leading to progressive fibrosis)
Etiology: bacteria (Farmer’s lung), fungi/mold, animal protein (bird droppings, urine), etc.
PE: diffuse crackles, fever, cough
CXR: nonspecific fibrosis and infiltrates
Diagnosis: Respiratory sxs that worsen in certain environments, antibodies against offending agent, environmental challenge
Treatment: Eliminate exposure, corticosteroids
