Lecture 8: Interstitial Lung Disease Flashcards
(82 cards)
1
Q
What is the interstitium of the lungs?
A
Region between alveolar wall and pulmonary capillary epithelial cells.
2
Q
What characterizies Interstitial Lung Disease (ILD)?
A
- Damaged alveoli and surrounding tissue
- DOE
- Persistent dry cough
- Late inspiratory rales on PE (forced opening of alveoli)
- CXR: septal thickening and reticulonodular damage.
3
Q
What structures are affected by ILDs?
A
- Alveolar epithelium
- Pulmonary capillary endothelium
- Alveolar basement membrane
- Perivascular tissues
- Perilymphatic tissues
The tissue and airspace around the air sacs of the lungs.
4
Q
What are the primary causes of ILDs?
A
- Idiopathic pulmonary fibrosis (MC)
- Occupational and environmental
- Sarcoidosis
- CT diseases
- Drug and radiation
5
Q
Describe the pathophysiology of ILDs.
A
- Injury to alveolar epithelium or capillary endothelial cells.
- Leads to progressive, irreversible scarring and stiffness of lung parenchyma.
- Poor O2 exchange.
6
Q
What is the proposed mechanism of ILD?
A
Repetitive and/or excessive injury, followed by dysregulation of tissue repair
7
Q
What are the two pathophysiologic presentations for ILD?
A
- Granulomatous lung disease (T cells, macrophages, and epithelioid cells)
- Inflammation and fibrosis (fibrotic alveoli)
8
Q
When do ILDs tend to appear?
A
Ages 20-40, with an insidious onset.
>60 would be idiopathic pulmonary fibrosis
9
Q
What is the general presentation of an ILD?
A
- Fatigue
- Weight loss
- Dyspnea
- Cough (dry)
Extrapulmonary symptoms can be seen if they have a CT disorder.
10
Q
What would be expected on a respiratory exam for ILD?
A
- Tachypnea
- Late inspiratory rales (bibasilar, posterior axilla)
- Rhonchi (associated bronchiolitis)
11
Q
What would be expected on a CXR for ILD?
A
- Bibasilar reticular or reticulonodular with honeycombing in late stage.
12
Q
What is an alternative to CXR that helps narrow ILD diagnosis?
A
High-res CT (HRCT)
13
Q
How do most ILDs present on PFT?
A
Restrictive, with TLC reduction first and then FEV1/FVC reductions.
14
Q
Which ILD could present as an obstructive pattern on PFT?
A
Sarcoidosis
50%
15
Q
Which test would be used to confirm results of decreased pulse oximetry for an ILD patient?
A
ABG.
16
Q
At what point does medicare reimburse for oxygen supplementation?
A
- 88% or less SaO2 on 6MWT.
17
Q
What is the function of bronchoalveolar lavage?
A
Obtain samples of cells and fluid for assessment of cell count, cultures, and cystologic analysis.
Usually non-specific for ILD.
18
Q
When is lung biopsy indicated for in ILD?
A
Last resort to confirm diagnosis or stage disease.
19
Q
What is the goal SaO2 for oxygen supplementation in ILD and when is it indicated?
A
- Indication: hypoxemia <= 88%
- Goal: 90-92%
Documentation: 2L O2 via NC
20
Q
What is the first-line pharmacotherapy for ILD?
A
Glucocorticoids, usually prednisone.
Re eval after 4-12 wks.
Starting dose: 0.5-1mg/kg PO daily.
21
Q
If an ILD patient has no improvement on glucocorticoids, what should be added?
A
Add immunosuppressant, such as cyclophosphamide, azathioprine, or mycophenolate mofetil (cellcept)
22
Q
What patient education should be provided regarding ILDs?
A
- Fibrosis is an irreversible condition
- Compliance is vital to slowing disease progression.
23
Q
What is the theory behind idiopathic pulmonary fibrosis? (IPF)
A
- Homeostasis of alveolar epithelial cells is disrupted, leading to abnormal cell repair and fibrosis.
- Excessive production and dysregulation of myofibroblasts occur.
24
Q
What are the clinical findings suggestive of IPF?
A
- Gradual onset of exertional dyspnea with dry cough.
- 55-60 y/o males
- Fine inspiratory crackles/rales w or w/o digital clubbing.
25
What should a PFT show for IPF?
* Restrictive lung pattern
* Reduced DLco
* Hypoxemia that worsens on exertion.
26
What should a HRCT of IPF show?
* Bibasilar, reticular opacities
* Traction bronchiectasis
* Honeycombing
27
What histiologic findings are characteristic of IPF?
Alternating areas of healthy, inflammation, fibrosis, and honeycomb change.
| Fibrosis is dominant over inflammation
28
What are the primary treatment agents for IPF?
* Nintedanib: Tyrosine kinase inhibitor
* Pirfenidone: anti-inflammatory agent; antifibrotic
| Prevents further scarring. Efficacy similar.
## Footnote
Caution in liver injury! Need LFTs
29
What should be done in terms of management for IPF to help treat it besides pharmacotherapy?
* Early referral for lung transplant.
* Encourage clinical trial participation
| Disease is irreversible!
30
What drug class is being researched for IPF?
Phosphodiesterase 4B inhibitors
31
What is sarcoidosis?
* Inflammatory disease of unknown etiology.
* Noncaseating (non-necrotizing) granulomas involving 2+ organ systems.
* MC organ: lungs.
* 2nd MC: Skin and eyes
32
What demographic is the most susceptible to sarcoidosis?
Young, female, African-American
| Will present more acute and severely.
33
How do Northern europeans present with sarcoidosis?
Much more milder and chronic.
34
What are the primary clinical findings in sarcoidosis?
* Dyspnea & cough
* Insidious fatigue, fevers, night sweats, wt loss
* Lung exam will most likely be normal unless advanced.
35
What are the skin clinical findings associated with sarcoidosis?
* Erythema nodosum (LE panniculitis)
* Lupus Pernio (violaceous rash on cheeks or nose)
* Maculopapular lesions (MC in chronic sarcoidosis)
36
What are the ocular clinical findings associated with sarcoidosis?
* Anterior/posterior granulomatous uveitis
* Anterior: insidious onset, pain, slight photophobia, blurred vision.
* Posterior: Painless, floaters, loss of visual field, scotomas, decreased VA
* Conjunctival lesions and scleral plaques
37
What abnormal lab findings are associated with sarcoidosis?
* Hypercalcemia (granulomas make 1,25-dihydroxyvitamin D)
* ESR (general inflammation)
* ACE (granulomas secrete ACE)
| ACE elevation is non-specific and non-sensitive.
## Footnote
ACEI use can produce low ACE levels even in the presence of sarcoidosis.
Lungs naturally create ACE!
38
What is the most sensitive pulmonary test for sarcoidosis?
DLco to check for diffusing capacity.
39
Describe the staging of sarcoidosis based on CXR presentation.
1. Stage 1 is isolated hilar adenopathy
2. Stage 2 is combination of adenopathy + hilar infiltrates
3. Stage 3 is infiltrates alone
4. Stage 4 consists of fibrosis
40
What specific part of the lung is used to support the diagnosis of sarcoidosis?
* Adenopathy size.
* > 2 cm in the short axis supports Dx of sarcoidosis over other ILDs.
| Requires HRCT and only used to compare vs other ILDs.
41
What is the confirmatory histiologic finding for sarcoidosis?
Non-caseating granuloma.
| Histology is the most confirmatory test for sarcoidosis.
42
When is thoracoscopy used over transbronchial biopsy?
Atypical imaging or less invasive testing was indeterminate.
43
What might a broncheoalveolar lavage show for sarcoidosis?
* Increased lymphocytes
* High CD4/CD8 ratio
| Not confirmatory
44
What is the only finding in sarcoidosis that does not require treatment?
Erythema nodosum.
| Very rare to be an isolated finding.
45
For acute sarcoidosis, what is the treatment?
| Acute = < 2 years for sarcoidosis.
* None-minimal symptoms: observe
* Single organ: systemic therapy unless anterior eye only.
* Multi-organ: Systemic glucocorticoids +/- immunomodulators
## Footnote
Anterior eye is only topical corticosteroids.
46
What is the treatment for chronic sarcoidosis?
| Chronic is 2-5 years without symptom resolution.
* If tolerable of glucocorticoids: stay
* If intolerable: use immunomodulators
* If not effective: taper off +/- immunosuppressants
47
What is the only efficacious treatment for advanced pulmonary fibrosis?
Lung transplant
48
What is the primary contraindication to ophthalmic corticosteroids?
Dendritic lesions
49
What are the 3 primary substances that cause pneumoconiosis?
* Coal mining
* Silicosis
* Asbestosis
50
How can PFTs vary for occupational/environmental lung disease?
* Uncomplicated: restrictive with decreased DLco
* Complicated: obstructive with decreased DLco
51
Define pneumoconiosis.
Chronic, fibrotic lung disease caused by the inhalation of inorganic dusts.
52
What is the treatment for pneumoconiosis?
Supportive. No medication has proven efficacy.
53
What is the pathophysiology of black lung?
Alveolar macrophages ingest inhaled coal dust leading to the formation of coal macules 2-5 mm in diameter.
## Footnote
Macrophages then die in the lungs, releasing all the coal they ingested.
54
What is the simple presentation of black lung?
* Asymptomatic
* Minimal change on PFTs
* Small, rounded opacities on CXR.
55
What is the complicated presentation of black lung?
* Symptomatic
* Diminished function on PFT
* Nodules >= 1cm in upper half of lungs.
56
Define silicosis.
Fibronodular lung disease caused by inhalation of dust containing crystalline silica.
57
How does acute silicosis present?
* Occurs in heavily exposed environments.
* Few weeks to years after exposure
* Cough, SOB, pleuritic pain, wt loss, faitgue
58
How does chronic silicosis present?
* Simple: asymptomatic or DOE and cough w/ sputum.
* Complicated: Cough, SOB, appetite loss, wt loss, malaise/faitgue
| Takes 15-20 years to develop changes.
59
What abnormal breath sounds are expected in silicosis lungs?
Rales
60
What is the expected finding on CXR/HRCT for simple silicosis?
Multiple, small (< 1cm) nodules scattered diffusely but more prominent in upper lung fields.
61
What is the expected finding on CXR/HRCT for complicated silicosis?
Bilateral upper lobe masses due to coalescence of nodules
62
What is the secondary concern for people with silicosis specifically?
Increased risk for pulmonary TB.
63
What is the pathophysiology of asbestosis?
* Asbestos fibers are inhaled, becoming ingested by macrophages.
* Results in inflammatory response, fibroblast proliferation, and chronic scarring.
| Asbestos stabs the macrophages
64
How does asbestosis present?
* Takes 20 years to appear usually.
* DOE is the MC symptom
* Bibasilar, fine end-inspiratory crackles
* Clubbing (< 50% of pts)
65
What is unique about asbestosis on CXR?
Formation of pleural plaques, generally on the parietal pleura.
## Footnote
Highly susceptible to mesothelioma.
66
Why is HRCT preferred over CXR for asbestosis?
Far more sensitive, as people can present with normal CXR but abnormal HRCT.
67
When is BAL used? What should it show for asbestosis?
* Non-diagnostic HRCT.
* Will show asbestos bodies
68
What must a patient with asbestosis be counseled on?
Smoking cessation, because it will increase their risk of developing mesothelioma greatly.
69
What is hypersensitivity pneumonitis?
Extrinsic inflammatory alveolitis due to exposure to inhaled, organic antigens leading to acute illness.
| Nonatopic, nonasthmatic!
70
What pathophysiology characterizes hypersensitivity pneumonitis?
Diffuse inflammation of interstitial lungs, terminal bronchioles, and alveoli.
71
How does acute hypersensitivity pneumonitis present?
* FLS
* Should improve if exposure is removed.
* CXR: poorly defined micronodular/diffuse interstitial pattern.
| Onset is within hours.
72
How does subacute/chronic hypersensitivity pneumonitis present?
* Insidious onset of wet cough, dyspnea, fatigue, anorexia, and wt loss.
* CXR: Fibrotic changes with loss of lung volume and coarse, linear opacities.
73
What secondary treatment can be provided for hypersensitivity pneumonitis besides removing the offending agent?
Oral corticosteroids in severe/protracted cases.
74
What factors contribute to radiation lung injury?
* Volume of lung irradiated
* Dose/rate of exposure
* Concurrent chemo, previous therapy, and withdrawal of corticosteroid therapy.
75
How does radiation pneumonitis present?
* Insidious onset of dyspnea, intractable dry cough, chest fullness, pain, weakness, and fever.
* Severe would present with respiratory distress or cyanosis
* Inspiratory rales
* CXR: Alveolar or nodular opacities limited to irradiated area + air bronchograms.
| Presents 2-3 months after radiation therapy completion.
76
How do we treat radiation pneumonitis?
Supportive. Steroids may be given.
77
What kind of patients are most susceptible to pulmonary radiation fibrosis?
Patients who received a full course of radiation therapy for **lung or breast cancer.**
78
What is the primary clinical symptom seen in pulmonary radiation fibrosis?
Slow, progressive dyspnea
79
What CXR findings are seen in pulmonary radiation fibrosis?
* Obliteration of normal lung markings
* Dense interstitial and pleural fibrosis
* Reduced lung volumes
* **Tenting of the diaphragm**
* Sharp delineation of the irradiated area
* Diminished R lung volume
80
What is the treatment for pulmonary radiation fibrosis?
Supportive. Steroids have no efficacy
81
What are the common CT diseases associated with ILDs?
* Progressive systemic sclerosis
* RA
* SLE
* Sjogren's
* Polymyositis and dermatomyositis
| Always evaluate for CTD if someone has an ILD.
## Footnote
Pulmonary symptoms can precede the CTD.
82
What are the MC symptoms associated with drug-induced ILDs?
* DOE
* Non-productive cough
