PAHTOPHYS: Restrictive Lung Disease Flashcards
What is a restrictive lung disease?
disease in which the expansion of the lungs are restricted
What can lead to the restriction seen in restrictive lung disease?
- PARENCHYMAL: Alterations of the lung parenchyma
- EXTRA-PARENCHYMAL: Disorders of the pleura, chest wall, or neuromuscular apparatus surrounding the lungs
List the 3 characteristics of restrictive lung disease.
1) Reduction in lung volume (lower TLC)
2) Absence of airflow obstruction
3) Reduction of diffusion capacity
List the lung parenchymal disorders.
1) Interstitial lung disease (ILD)* most common
2) Resection of the lung tissue
List the extra-parenchymal disorders.
1) Diseases of the pleura (ex. pleural effusion)
2) Diseases of the chest wall
3) Neuromuscular Disorders
What is the interstitium?
the extra-vascular and extra-alveolar compartment of the lung parenchyma
Interstitial lung diseases predominantly involve what tissue?
connective tissue of the alveolar wall (space between endothelium and epithelium)
What is ILD?
Inflammatory process involving all of the components of the alveolar wall that commonly result in the excess growth of CT with distortion of the lung architecture and dysfunction of gas exchange
List the 3 structural components of ILD?
1) Parenchymal cells (type I and type II epithelial cells and endothelial cells)
2) Inflammatory cells (macrophages, lymphocytes, neutrophils)
3) CT elements (cells, fibers, ground substances)
What is a type 1 epithelial cell?
Predominant structural cell that covers over 90% of the epithelium (thin, pancake like) that is very vulnerable to injury
What is a type 2 epithelial cell?
Cuboidal cells interspersed between type-1 that makes surfactant to be stored in lamellar bodies and repopulates type 1 cells following injury
List a lung disease that is associated with normal lung volume?
pulmonary HTN
In what set of pulmonary diseases is the diaphragm higher, obstructive or restrictive?
restrictive!
Why is the DLCO lower in ILD?
surface area is decreased, wall is thickened
Is air flow reduced in ILD?
NO
What is the pathogenesis of ILD?
Injury to epithelial cells leads to the release of growth factors (TGF-Beta, PDGF, etc.) which recruits fibroblasts to play down collagen and form fibrosis
What are the two forms of ILD with known etiology?
1) Granulomatous (berylliosis, hypersensitivity)
2) Non-granulomatous (asbestosos, coal, silica, drugs)
What are the two forms of ILD with unknown etiology?
1) Granulomatous (sarcoidosis)
2) Nongranulomatous (IIP, etc.)
The hypoxemia of ILD is mostly due to what?
V/Q mismatch (thickening of alveolar wall by CT fibers and cells as well as increased inflammation in lumen affects ventilation!)
Describe the breathing of someone with restrictive lung disease.
Rapid, shallow breathing
What are the hallmarks of ILD on PFTs?
Reduced TLC
Reduced Vital capacity
Reduced DLCO
*DOES NOT alter expiratory airflow
What are the most common symptoms of ILD?
Dyspnea**
Cough
Chest pain
Hemoptysis
What are the most common signs of ILD?
Tachypnea Crackles (velcro rales) Digital clubbing Cor-pulmonale (late) Cyanosis (late)
What is an early stage radiological feature in ILD?
alveolar filling phase –> ground glass
What is a mid-stage radiological feature in ILD?
interstitial phase –> reticulation (lines crossing one another)
What radiological finding of ILD suggests end-stage-lung disease?
Honeycomb lung
True or false: smoking can cause ILD.
True! but it more commonly causes COPD
How do you dianose ILD?
History (genetic, environment, occupation, medical) Physical Imaging with comparison! PFTs BAL and Lung Biopsy
What is BAL?
Broncho-Alveolar Lavage- send a bronchoscope into the alveolar space and suck out fluid (and cells that line the alveolar lumen: macrophages, lymphocytes, PMNs)
What do you see in a BAL of sarcoidosis?
tons of lymphocytes
What do you see in a BAL of idiopathic fibrosis?
tons of neutrophils
List some diseases of the pleura.
- Mesothelioma
- Pleural effusion
- Pneumothorax
List some diseases of the chest wall.
-Kyphoscoliosis
List some neuromuscular diseases.
- Lou Gherig’s Disease
- Myesthenia gravis
