W4 Restrictive Lung Disease Flashcards
What are restrictive diseases?
Characterised by ?
What are the diseases of the pleura
Chest wall?
Diseases in which the expansion of the lung is restricted either because of alterations in the lung parenchyma or because of the pleura, chest wall, or neuromuscular apparatus.
Characterized by:
—Normal or slightly higher FEV1/FVC
—Reduced Vital Capacity
—Small Resting Lung Volume
—No Change in Airway Resistance
Diseases of the Pleura:
—Pneumothorax
—Pleural Effusion
Diseases of the Chest Wall
—Scoliosis
—Ankylosing Spondylitis
Neuromuscular Disorders
Diseases of the lung parenchyma
Intrinsic causes
What are the 6 main causes?
Diseases of the Lung Parenchyma = Interstitial Lung Disease or Diffuse Parenchymal Lung Disease
Including the interstitium or structural tissue between the alveolar epithelium and pulmonary capillary endothelium. Also contains collagen, elastic tissue, fibroblasts, and mast cells: Excess deposition makes the lung stiff
1.Diffuse Interstitial Pulmonary Fibrosis (IDIOPATHIC pulmonary fibrosis, interstitial pneumonia, cryptogenic fibrosing alveolitis)
2.Sarcoidosis, system disease, effects multiple organs (Granunomatous)
3.Hypersensitivity Pneumonitis (Granunomatous)
4.Drugs (amiodarone, nitrofurantoin) and Radiation
5.Inhaled Particles (Pneumoconiosis, dust particles, mostly from occupational hazards)
6.Collagen Vascular Disease (Scleroderma, Wegener’s
Goodpasteurs and Churg Strauss)
Granuloma: macrophages surrounding pathogen/antigen, it’s like a standoff. Immune response arrives, then you get a clump ball
Diseases of the lung parenchyma
Pathology
What is the principle feature?
What do you see with the alveoli? What is the term for the appearance?
Leads to?
Summary:
thickening of alveolar wall: trigger (dust/allergen) — immune rxn — fibroblasts lay down collagen — fibrosis — honeycomb alveoli — decreased diffusion d/t thickness — vasoconstriction — de-recruitment of capillaries — pulmonary HTN
Principal feature is THICKENING OF THE INTERSTITIUM OF THE ALVEOLAR WALL
Exposure to a TRIGGER leads to ALVEOLAR MACROPHAGE activation — like a dust particle, antigen like in sarcoidosis.
Initially there is an immune reaction with cytokine damage to the alveolar epithelium
Later, FIBROBLASTS appear and lay down COLLAGEN BUNDLES to attempt to repair these areas
Eventually, the alveolar architecture is destroyed and SCARRING/FIBROSIS results.
This causes multiple air filled spaces/cysts surrounded by fibrosed dilated terminal and respiratory bronchioles (HONEYCOMB LUNG) : this is thickening of the interstitium IN the alveolar. See the image for thickening within the alveoli
HYPOXIA
—Increased interstitial and respiratory membrane thickness causes DECREASED DIFFUSION of gases and hypoxemia (most common cause in restrictive lung disease)
—Hypoxia to affected areas result in pulmonary vasoconstriction and movement of pulmonary capillary blood to better ventilated alveoli where there is better gas exchange. This is “de-recruitment” of the crappy capillaries.
—As the disease progresses, it becomes more widespread resulting in increased vasoconstriction and ultimately increased pulmonary vascular resistance
—Leads to pulmonary hypertension, RVH, and cor pulmonale
Restrictive disease
S/S : top 3
Imaging — what would you see on CXR
S/S
⭐️Dyspnea
⭐️More significant with exercise
⭐️Irritating, nonproductive cough
Hemoptysis (alveolar hemorrhage)
Wheeze and chest pain (possible but uncommon)
Velcro crackles on auscultation
Clubbing
Cor Pulmonale : signs of right sided heart failure
Chest X-Ray
—Normal
—Reticular or Reticulonodular pattern (mostly at bases) with small lung expansion / baby lung
—Ground Glass Opacities (opacification due to air displaced by fluid, airway collapse, fibrosis : when a substance other than air fills an area of the lung it is more dense and appears grey/hazy as opposed to dark. Keep in mind this can be seen in many conditions)
—⭐️Mediastinal / HILAR LAD = SARCOIDOSIS!
—image attached: reticular, in both lung fields, no fluid in pleural space, hazy.
CT Scan (gold standard)
—includes RETICULONODULAR and ground glass findings
—Honeycomb pattern: classic term for restrictive disease
—Attached image top: see a lot of grey, hazy patterns, ground glass opacities
—bottom image in this answer, lung fibrosis, honeycomb
[SKILLS OSCE]
What is this?
Restrictive lung disease?
Restrictive disease
Spirometry:
FVC
FEV1
Ratio
All other lung volumes
Other DX studies
SPIROMETRY —you have small lungs!
1. FVC reduced and FEV1 reduced
1. The gases are exhaled normally so the FEV1/FVC ratio is NORMAL or possibly even slightly elevated
- All lung volumes are reduced: TLC, FRC, and RV
- The arterial PaO2 and PaCO2 are typically reduced and the pH is normal
- The DLCO (diffusing capacity for carbon monoxide) is REDUCED in INTRINSIC disease secondary to the thickening of the blood-gas barrier and some destruction of capillaries by fibrosis (normal in extrapulmonary causes). As opposed to extrinsic, like MSK issues like pectus excavatum/pleural effusion etc.
- Destruction of the capillaries and narrowing of the capillary lumen by smooth muscle proliferation, increase pulmonary vascular resistance. This worsens during exercise, and gives a more profound drop in oxygen
Other Diagnostic Studies
NONSPECIFIC:
—CBC, chemistry panel including LFTs/vitamin D level, calcium, muscle enzymes, ESR/CRP
—Serum ACE level (Sarcoidosis)
—Collagen Vascular Disease (Autoantibody Tests)
C-ANCA, P-ANCA, (vascular disorders) ANA, anti-dsDNA, anti-SMith, RF, anti SCL-70, anticentromere, anti-JO1
—Lung Biopsy
Restrictive lung disease
Treatment
Two agents to slow progression
One is the main other supplementary agent? (On quiz)
Invariably fatal process with the majority of patients dying within 5 years of the diagnosis
TREAT UNDERLYING CAUSE / REMOVE TRIGGER
No treatment has shown to improve mortality.
These agents can slow progression by inhibiting fibroblast proliferation:
- TYROSINE KINASE INHIBITOR (NINTEDANIB)⭐️
- ANTIFIBROTIC AGENT (PIRFENIDONE ) ⭐️
⭐️ON QUIZ: Steroids / Immunosuppressants (prevent further damage from inflammation possibly related to Granulomatosis or Collagen Vascular Disease)
—Pulmonary Rehab
—Lung Transplant
—Home Oxygen
—SpO2 < 88% or PaO2 < 55 mmHG
—Vaccinations
Sarcoidosis
What is it?
Presentation? Which population/demographic
Imagine
Characterized by the presence of granulomatous tissue and can occur in several organs (skin, liver, spleen, eyes, lungs) and lymph nodes — it is SYSTEMIC
Immunologic cause where an unknown antigen is recognized by an alveolar macrophage resulting in a lymphocyte response that surrounds it. The macrophage may also STIMULATE FIBROBLASTS resulting in fibrous deposition in the interstitium
Present with a dry cough and dyspnea.
African American females
Can be associated with uveitis, arthritis, and parotid gland enlargement as well as other CNS and cardiac manifestations
IMAGING:
—Enlarged mediastinal lymph nodes
—⭐️BILATERAL HILAR LYMPHADENOPATHY ⭐️
—Reticular Opacities
—Pulmonary Fibrosis
TREATMENT:
—Often tx is observation if asymptomatic
—May require no treatment and the disease can enter remission.
—Patients with worsneing PFTs, symptoms, or extrapulmonary involvement should be given
💊CORTICOSTEROIDS
ACE Levels Super High
—A.American
—cough
—erythema
—lupus
—steroids
—hilar LAD
[SKILLS OSCE]
What is this?
Describe what you see
Sarcoidosis
Bilateral hilar LAD
Enlarged mediastinal lymph nodes
Reticular opacities
Pulmonary fibrosis
HYPERSENSITIVITY PNEUMONITIS
Results from?
S/S
What will you see on CT? Where in the lung?
Spirometry pattern?
Treatment?
Results from a hypersensitivity reaction to inhaled organic dusts.
The exposure is usually related to an occupational work environment (farmer’s lung)
Includes moldy hay, bird feces, and air conditioners
Pathology:
Alveolar walls are thickened and infiltrated with lymphocytes and eosinophils with some formation of small granulomas. Usually affects the small bronchioles. Over time, fibrotic changes will occur.
Acute with symptoms 4-6 hours after exposure (dyspnea, fever, cough) which continues for 1-2 days
Or chronic with progressive dyspnea over years with no associated acute attacks
In chronic disease the CT scan will show fibrosis of the upper lobes
Remember, comes from the earth so will appear in the upper lobes
Spirometry will show a restrictive pattern
TREATMENT:
Remove offending antigen with corticosteroids (long courses)
Pneumoconiosis
What is this? Aka?
Which profession associated?
Patho?
PNEUMOCONIOSIS refers to parenchymal lung disease caused by DUST INHALATION
PATHOLOGY
Particles enter the alveoli are engulfed by macrophages. Once engulfed, they migrate to the small airways where they load onto the mucociliary escalator OR they leave via lymphatics.
When the dust burden is large, macrophages migrate through the walls of the respiratory bronchioles and dump the dust there.
If the dust is toxic, a FIBROUS reaction begins.
COAL WORKER’s PNEUMOCONIOSIS: “Black Lung”
—In simple disease: aggregations of coal particles around the terminal and respiratory bronchioles with some dilation of the airways
—In advanced disease: progressive, massive FIBROSIS occurs with masses of black fibrous tissue infiltrated with dust
S/S: cough, dyspnea, and respiratory failure (advanced disease)
Silicosis
Which environmental exposure?
Where in the lung?
The pneumoconiosis caused by inhalation of silica during quarrying, mining, or sandblasting.
More toxic than coal and provoke a more serious fibrous reaction in the lung: upper lobes.
Silicotic nodules composed of dense collagen are found around respiratory bronchioles, inside alveoli, and along the lymph.
Advance disease results in cough and dyspnea (especially on exercise)
Chest x-ray will show:
—streaks of fibrous tissue with possibility to develop —massive fibrosis
Asbestosis
PE, S/S
CXR findings
Naturally occurring fibrous mineral silicate used in industrial applications including heat insulation, roofing material, and brake linings.
Asbestosis fibers are long and thin allowing them to penetrate far into the lung.
When in the lung, they become encased in a proteinaceous material and can be coughed up : known as asbestosis bodies
Can lead to:
Interstitial Fibrosis: dyspnea (especially on exercise), weakness, and clubbing.
On auscultation there are crackles.
Chest x-ray shows reticular opacities and may show asbestosis calcified plaques.
Pleural Thickening with possible development of malignant mesothelioma (up to 40 years after
exposure).
Mesothelioma is a cancer that develops in the thin layer of tissue covering the lung (as well as heart, abdomen). Progressive restriction of chest movement, severe chest pain, and poor prognosis.
What is farmer’s lung?
HYPERSENSITIVITY PNEUMONITIS
