Restrictive Lung Disease Flashcards
What defines restrictive lung disease?
A heterogeneous group of diseases that cause lung fibrosis, distortion of lung structure, and impaired gas exchange.
What are the two main classifications of restrictive lung disease?
Intrinsic (interstitial lung disease) and extrinsic (chest wall or neuromuscular disorders).
What are common symptoms of restrictive lung disease?
Dyspnea, nonproductive cough, diffuse crackles, clubbing, and impaired gas exchange.
What PFT findings indicate restrictive lung disease?
- Low TLC
- Low RV
- Low FEV1
- Low FVC
- High FEV1/FVC ratio >85%.
How is restrictive lung disease diagnosed?
History, physical exam, high-resolution CT (HRCT), pulmonary function tests (PFTs), and possibly lung biopsy.
A 62-year-old man presents to the primary care clinic due to a persistent cough that began four months ago. The cough is dry without sputum production. Recently, he has experienced more difficulty walking around the house, and he needs to stop to catch his breath while doing daily life activities. His past medical history unremarkable, and he takes no medications. Temperature is 37.0 °C (98.6 °F), pulse is 90/min, respiratory rate is 20/min, blood pressure is 110/71 mmHg, and oxygen saturation is 89% on room air. On physical examination, the patient appears fatigued. There are fine inspiratory crackles throughout both lungs, and finger clubbing is noted. A chest radiograph shows multiple reticulonodular opacities. High-resolution computed tomography (CT) imaging of the chest is ordered. Which of the following is the most likely diagnosis?
This 62-year-old man presents to the clinic with a chronic dry cough, dyspnea, and hypoxia. The physical examination findings of fine inspiratory crackles and clubbing, and the reticulonodular opacities seen on chest x-ray are suggestive of interstitial lung disease. A chest radiograph can assist in the evaluation of subacute or chronic cough. A normal chest radiograph may be seen in nonasthmatic eosinophilic bronchitis, gastroesophageal reflux disease, upper airway cough syndrome, asthma, and early/mild COPD. An abnormal chest radiograph can be seen with atypical pneumonia (bilateral patchy infiltrates and a convincing patient history), bronchiectasis, interstitial lung disease, advanced COPD, and lung cancer and requires follow-up testing, including imaging. When Interstitial lung disease is suspected based on history, examination, and chest radiography, pulmonary function testing, and high-resolution chest CT imaging should be ordered next. Reticulations, ground glass opacities, and honeycombing may be seen on chest CT imaging. Specific findings on chest imaging, environmental exposures, and potential biopsy findings help determine the type of interstitial lung disease. Interstitial lung disease can cause cough, dyspnea on exertion, hypoxia, digital clubbing, and fine inspiratory crackles on exam. Chest radiographs may show reticular and/or nodular opacities. Pulmonary function tests and high-resolution CT imaging should be the next steps in the diagnosis of suspected interstitial lung disease.
What are the main pneumoconioses?
Coal worker’s pneumoconiosis, silicosis, asbestosis, and berylliosis.
What imaging finding is characteristic of silicosis?
Eggshell calcifications in the upper lobes.
What malignancy is most associated with asbestosis?
Bronchogenic carcinoma (more common than mesothelioma).
What occupation is at risk for berylliosis?
Aerospace, nuclear, and electronics industries.
What are the key granulomatous diseases in restrictive lung disease?
Sarcoidosis, histiocytosis X, and vasculitis.
What is the hallmark finding of sarcoidosis?
Non-caseating granulomas in multiple organs.
What are the classic radiographic findings in sarcoidosis?
Bilateral hilar lymphadenopathy and reticular opacities.
What are examples of alveolar filling diseases?
Goodpasture syndrome and pulmonary alveolar proteinosis.
What is the pathophysiology of Goodpasture syndrome?
Autoantibodies against the alpha-3 chain of type IV collagen in the alveoli and glomeruli. This causes patients to present with hemostasis and hematuria.
How is Goodpasture syndrome treated?
Plasmapheresis, prednisone, and cyclophosphamide. Treatment is very important because these patients can progress to develop rapidly progressive glomerulonephritis.
What is pulmonary alveolar proteinosis?
Accumulation of surfactant-like material in the alveoli due to impaired clearance.
What causes hypersensitivity pneumonitis?
Type III and IV hypersensitivity reactions to inhaled organic dust (e.g., mold, birds, hay). This causes a decrease ratio of CD4/ CD8. It can present acutely within hours or chronically with cough, dyspnea, fatigue, and weight loss. The CT will show ground glass or The CT will show ground glass or nodular opacities.
What is the treatment for hypersensitivity pneumonitis?
Avoidance of exposure and corticosteroids if severe. If irreversible fibrosis develops you can do a lung transplant.
How does eosinophilic pneumonia present?
Usually acute less than four weeks, with illness involving cough,dyspnea, and systemic symptoms. Patients usually have hypoxemic respiratory failure. On CT patients will show diffuse pulmonary opacities.
What is the diagnostic test for eosinophilic pneumonia?
BAL showing >25% eosinophils. Treat with supportive care and steroids.
What drugs commonly cause interstitial lung disease?
Amiodarone, nitrofurantoin, bleomycin, and methotrexate.
Which drug is associated with lung fibrosis and thyroid dysfunction?
Amiodarone.
How is drug-induced lung disease treated?
Drug cessation and corticosteroids if needed.
What autoimmune diseases can cause restrictive lung disease?
Rheumatoid arthritis, systemic lupus erythematosus (SLE), and scleroderma.
What is the most common lung manifestation of scleroderma?
Pulmonary fibrosis and pulmonary hypertension.
What are the two main types of idiopathic interstitial pneumonia?
Idiopathic pulmonary fibrosis (IPF) and cryptogenic organizing pneumonia (COP). Idiopathic pulmonary fibrosis is associated with CREST syndrome and the risk factors involved increase age and cigarette smoking. Cryptogenic organizing pneumonia usually has a flu like prodrome, but the patient is unresponsive to antibiotics.
What is the classic CT finding of idiopathic pulmonary fibrosis?
Honeycombing and reticular opacities.
What drugs are used to slow the progression of IPF?
Pirfenidone and nintedanib. The prognosis is pretty dire for idiopathic pulmonary fibrosis with a 2 to 5 year life expectancy.
What is the key feature of cryptogenic organizing pneumonia (COP)?
Flu-like illness (cough, fever, malaise) with patchy interstitial opacities that do not respond to antibiotics. CT shows interstitial opacities, ground glass, and nodular opacities.
How is cryptogenic organizing pneumonia treated?
Corticosteroids.
What are the main neuromuscular causes of restrictive lung disease?
Myasthenia gravis, multiple sclerosis, and amyotrophic lateral sclerosis (ALS).
What are the main chest wall abnormalities causing restrictive lung disease?
Obesity hypoventilation syndrome, scoliosis, and ankylosing spondylitis. The PFTs for these diseases are low TLC, low FVC, but normal to high RV.
How does obesity hypoventilation syndrome present?
Daytime sleepiness, shortness of breath, hypercapnia, and a normal A-a gradient and normal DCLO. This can be diagnosed with clinical exam and history showing a BMI over 30 along with ABG showing respiratory acidosis. Treatment is to recommend weight loss.
What is the treatment for obesity hypoventilation syndrome?
Weight loss, CPAP/BiPAP, and lifestyle modification.
What is acute interstitial pneumonia?
A rare, fulminant lung injury resembling ARDS but without a clear trigger.
How is acute interstitial pneumonia diagnosed?
Lung biopsy showing diffuse alveolar damage.
What is the treatment for acute interstitial pneumonia?
High-dose corticosteroids.
