How is restrictive physiology defined? (PFT values)
Total Lung Capacity less than 80% predicted.
Functional Residual Capacity (Thoracic Gas Volume) less than 80% predicted.
Symmetrically reduced FEV1 and FVC (ratio still the same)
Restrictive physiology may be caused by ______ in lung elastic recoil or disease in the ______ or _____.
Increase, chest wall, pleura
What is the relaxation pressure?
Relaxation pressure is the measure of the total compliance of a system. This takes the compliance of the chest wall as well as the compliance of the lung into account.
True or False: The pressure-volume curves that we typically look at are only depicting the lung compliance, not chest complaince.
True! This is why changes in the chest wall compliance do not affect the slope of the curve, they only shift the whole thing up or down.
What is elasticity?
Elasticity is the tendency of a structure to return to its initial form after deformation (e.g. springs with high elastic recoil (elastance) has stronger tendency to return to its resting state when stretched)
Compliance is the inverse of _____
Generally, ______ diseases make it hard to exhale and _______ diseases make it hard to inhale
Inflammation or scarring may expand the _____ and reduce _____
How does pulmonary edema increase elastic recoil/decrease compliance?
Pulmonary edema can increase the mass of the interstitium making it thicker and stiff. It can also deplete surfactant and increase mass and stiffness of the parenchyma.
How can surfactant depletion increase elastic recoil/decrease compliance?
Surfactant depletion increases alveolar surface tension which leads to alveolar collapse
All alveolar filling processes increase _______ and decrease ____
Pleural effusion, Asbestos-related pleural plaque, and Kyphoscoliosis all ____ the overall _____ by decreasing ____ of the _____
decrease, compliance, compliance, chest wall
How can you determine between restrictive lung disease and restrictive physiology?
In restrictive lung disease, the slope of the P-V curve is reduced. In restrictive physiology, the slope of the P-V curve is preserved but the whole curve is shifted downloards.
DLCO/VA is reduced in restrictive disease but preserved in restrictive physiology.
True or False: Restrictive chest wall diseases generally do not cause gas exchange problems.
True. Restrictive chest wall (restrictive physiology) generally doesn't cause gas exchange problems unless very severe.
How is gas exchange impaired in restrictive lung disease?
There is a loss of alveolar surface area due to decreased lung volumes and decreased alveolar volumes. Also, the thickening of the alveolar walls limits diffusion.
DLCO is corrected for _______ using helium dilution technique
alveolar volume (VA)
When there is restrictive physiology, DLCO will _____
decrease in proportion to volume but DLCO/VA (DLCO corrected for VA) is normal
When there is restrictive lung disease present, there is a reduction in _____
DLCO AND DLCO/VA
Note that with restrictive lung disease, DLCO is decreased and is still decreased even after correcting for alveolar volume (except for in patients with early stage pulmonary fibrosis). With restrictive physiology, the correction of alveolar volume will make the value normal
Name 4 acute restrictive processes
1. Pulmonary edema
4. Pleural effusion
Name 3 chronic restrictive processes
1. Interstitial lung disease
2. Pleural fibrosis/plaques
3. Pleural effusion
Restrictive processes can be acute or chronic. What is more common?
If a patient has reduced lung voluems AND reduced FEV1/FVC, do they have obstructive or restrictive disease?
They have a mix of obstructive and restrictive disease
Give 4 common examples of mixed obstructive disease
1. coal miner (interstitial disease from occupation) who smokes (emphysema)
2. obese person (chest wall restriction) with poorly controlled asthma (obstructive)
3. combined pulmonary fibrosis and emphysema
4. fibrotic hypersensitivity pneumonitis (causes mixed)
5. sarcoidosis (causes mixed)
What is interstitial lung disease?
ILD is a heterogeneous group of disorders characterized by a combination of inflammation or scarring.
Pulmonary fibrosis is characterized by ___
How do patients with interstitial lung disease typically present? (5)
1. Dyspnea with exertion
3. Subacute to insidious timing
4. Restrictive PFTs with decreased DLCO
5. Abnormal lung imaging
There are many kinds of interstitial lung disease (hundreds). Why is specific diagnosis for interstitial lung disease important?
It is important to be specific with diagnosis because prognosis varies a lot between different types of ILD.
how do you diagnose interstitial lung disease? (3 steps)
Clinical, radiographic, pathologic.
1. The clinical context has to do with associated diseases, exposures, occupation, drugs, lab testing.
2. High resolution CT (to look for pattern of damage)
3. Pathologic pattern on surgical lung biopsy
You need all 3 of these. Etiology alone is insufficient because diseases can manifest in many different injury patterns. Pathology patterns alone are insufficient too because pattern of involvment can be a result of many different diseases. You need to combine all 3 strategies to narrow down the diagnosis.
What 3 things do you look for in physical exam for ILD?
Auscultation: end-inspiratory velcro-like crackles
Digital clubbing in advanced cases of ILD
Joint and skin exam is important in identifying coexistent (causitive?) collagen vascular disease
What are the treatment options for ILD?
1. Remove offending exposure if possible (at home, at work, etc)
2. Immunosuppressive therapy (depends on type and etiology). In many of the ILD cases, the patients' immune system is attacking the lungs so immunosuppression can help.
3. Idiopathic pulmonary fibrosis is non-inflammatory so they need to be treated by nintedanib and pirfenidone to slow the fibrosis.
What is idiopathic pulmonary fibrosis?
Idiopathic pulmonary fibrosis is a scarring lung disease with a pattern of injury of usual interstitial pneumonia (UIP).
True or False: Idiopathic pulmonary fibrosis is a disease of younger patients
False! IPF is a disease that occurs in older patients (typically 60 and older)
True or False: Idiopathic pulmonary fibrosis is not associated with tobacco use.
FALSE! IPF is associated w/ tobacco use
What is the median survival from diagnosis of idiopathic pulmonary fibrosis?
What does idiopathic pulmonary fibrosis look like with HRCT?
There is peripheral and basical predominant reticulation. This is the web/lined appearance at the periphery of the lungs. In normal lungs, the last cm or two of the periphery should be clear as the airways become microscopic but with IPF there are pronounced lines. There is also traction bronchiectasis (airways being pulled open by the surrounding lung parenchyma).
What does idiopathic pulmonary fibrosis look like in histology?
Spatially and temporally heterogenous fibrosis with fibroblast foci, juxtaposition of fibrotic and normal lung.
What are 2 medications that can slow down the fibrosis in idiopathic pulmonary fibrosis?
What is nonspecific interstitial pneumonia (NSIP)?
It is an interstitial disease that presents similarly to other interstitial lung diseases. It may be idiopathic, collagen vascular disease related (RA, Sjogren's, scleroderma, myositis), fibrotic HP, or drug-related.
Nonspecific interstitial pneumonia happens most often affects what age and gender?
Is prognosis better for idiopathic pulmonary fibrosis or nonspecific interstitial pneumonia?
Prognosis is better for nonspecific interstitial pneumonia
True or False: Nonspecific interstitial pneumonia does not respond to anti-inflammatory therapy.
False. Nonspecific interstitial pneumonia responds to anti-inflammatory therapy
How does nonspecific interstitial pneumonia look in HRCT?
Basilar predominant reticular abnormality with volume loss, traction bronchiectasis, and frequently presenting with ground glass opacity. Rarely, there is honeycombing
What are the histological findings for nonspecific interstitial pneumonia?
Temporally homogeneous fibrosis with varying degrees of inflammation and fibrosis.
Respiratory bronchiolitis interstitial lung disease, desquamative interstitial pneumonia, and pulmonary langerhans cells histiocytosis are 3 diseases categorized under _____
-imaging: cysts and nodules
-upper lobe predominant
-15% extrapulm disease--including bone lesions, pituitary involvement
-treatment is smoking cessation
What is the disease?
Pulmonary langerhans cell histiocytosis (PLCH) (a type of smoking-related ILD)
What is pneumonia?
Inflammation in the alveoli. It can be either infectious or noninfectious (most comonly it's infectious)
What is idiopathic organizing pneumonia called?
cryptogenic organizing pneumonia
What can cause organizing pneumonia?
It can be idiopathic, or secondary to an underlying disease, drugs, or exposures.
What does organizing pneumonia look like under HRCT?
Ground glass and consolidation that can migrate over time.
What is typical treatment for organizing pneumonia?
Very responsive to steroids, but it can take 6-12 months of treatment. Relapse is possible with steroid withdrawal
What is eosinophilic pneumonia?
Eosinophils filling alveolar spaces
Is eosinophilic pneumonia infectious or non-infectious?
How does eosinophilic pneumonia present? What does it mimic?
It mimics ARDS and presents with acute respiratory failure
How is eosinophilic pneumonia diagnosed?
It is diagnosed by sampling the fluid in the alveolar spaces to see if there are eosinophils
How is eosinophilic pneumonia treated?
They resolve with steroids
Is eosinophilic pneumonia acute or chronic?
It can be either. Chronic eosinophilic pneumonia is subacute onset with associated asthma while acute mimics ARDS and presents with acute respiratory failure.
With eosinophilic pneumonia, is there an increased eosinophil count in blood?
There is an increased eosinophil count in blood in chronic eosinophilic pneumonia
What is lymphangioleiomyomatosis?
A mutation in tuberous sclerosis gene 1 or 2 causes this cystic lung disease that occurs exclusively in young women. There is peribronchovascular proliferation of smooth muscle cells. These basically block off distal airways and produce cysts and nodules. There is obstructive pattern on PFTs and spontaneous pneumothorax and chylothorax are common (remember that anything with cysts increase chance of pneumothorax). This disease sometimes produces renal tumors as well.
This disease is potentially treated with mTOR inhibitors (sirolimus)
What is a granuloma?
A collection of inflammatory cells that forms a ball that gets surrounded by cells that start to look like epithelial cells. This is an immune reaction.
What is sarcoidosis?
It is a systemic granulomatous disorder of unknown etiology. It commonly affects lungs, eyes, and skin
True or False: Sarcoidosis doesn't typically appear on CXRs
False. Sarcoidosis causes abnormal CXR in up to 90% of sarcoidosis cases
True or False: Lympadenopathy is common for sarcoidosis patients
True or False: Sarcoidosis may present as a mix of obstructive and restrictive processes
True. There is airway involvement in up to half of sarcoidosis cases and there may be restrictive, obstructive, or mixed PFTs in sarcoidosis.
How do sarcoidosis patients present?
Cough, chest pain, and sometimes wheezing
Does sarcoidosis typically appear before 40 y/o or after?
Before 40 y/o
What's going on here?
This CXR has bulky lymph nodes (hilar and paratracheal). This is a hallmark of sarcoidosis.
What's going on here?
This is a form of sarcoidosis that shows a net-like pattern affecting the upper lobes. The scarring in the upper lobes is pulling up the airways (you can see the main bronchi bending upwards).
How do you diagnose sarcoidosis?
You need to find granulomas that are idiopathic by excluding other causes of granulomas, there needs to be the clinical findings of cough, chest pain, or wheezing.
How do you treat sarcoidosis?
Sarcoidosis typically resolves on its own but if there is progressive organ injury, you need to treat with immunosuppression (steroids or cytotoxic drugs)