Restrictive Lung Disease Flashcards
Main Points
Restrictive Lung Diseases cause a decrease lung volume
Can be caused by extrinsic or intrinsic factors
DLCO in Restrictive Lung Disease
Early–can’t transport oxygen from air to alveoli to blood causes hypoxemia
Late–Can’t transport carbon dioxide from blood to alveoli to air causing carbon dioxide retention
Extrinsic causes of restrictive lung disease
Neuromuscular disorders (myasthenia gravis, Guillan Barre, ALS, polio)
Disorders of the chest wall (musculoskeletal deformities, obesity (Pickwickian Syndrome))
Pleural thickening
Intrinsic Restrict Lung Disease Synonyms
Interstitial Lung Disease
ILD
DIffuse parenchymal lung disease
DPLD
Fibrotic lung disease
Intrinsic Restrive Lung Disease Classification
Characteristics:
- diffuse lung injury
- inflammation
- progresses to irreversible fibrosis
- severely compromised gas exchange
Classification based on location
- Bronchiolities
- Alveolitis
- Vasculitis
- Combination
Classification may be baed on etiology
Example Etiologies of ILD
Environmental and occupational exposure
hypersensitivity
idiopathic
drug induced
radiation
Epidemiology of ILD
Relatively Uncommon
Onset and mortality varies depending on underlying etiology
Restrictive pattern on PFTs of ILD
Reduced FVC
Reduced FEV1
Normal FEV1/FVC
Pathophysiology of ILD
Decreased dispensability of lung. VC and TLC decrease as lung becomes stiffer
Loss of capillary and alveolar surface area–hypoxemia and respiratory alkalosis
V/Q mismatch
Hypoxemia: early with exercise, later at rest
Tachypnea is common
Hypercapnea is common only in severe or terminal cases
Pulmonary HTN in late cases
Disortation of airways may cause obstruction in advanced cases
Correlation between sxs, radiographic abnormalities, and physiologic abnormalities is poor
Symptoms of ILD
cough
dyspnea
Physical Findings of ILD (general)
Tachypnea
Tachycardia
Low O2 sat
Lungs: rales or wheezes
Heart: may have signs of right sided heart failure in severe cases
clubbing
Diagnosis of ILD
History
- Onset may be insidious, subacute with relapsing and remitting course or may be fulminant
**Physical **
**Testing **
- PFT
- Associated labs for underlying disease
- CXR: diffuse lung disease
**Lung Biopsy **
- Thoracoscopy
- Open lung biopsy
Idiopathic Pulmonary Fiborsis
Progressive disease of unknown original resulting in pulmonary fibrosis
Generally put into 4 categories
Most pts progress to end stage fibrosis and die
Time course and prognosis depends on category
Pneumoconiosis
Coal minors lung, abestosis, silcosis
PE: normal; crackles; clubbing
CXR: diffuse reticulonodular infiltrates, eggshell calcifications of hilar nodes
Lab: nonspecific
Fibrosis: different types depending on agent exposed to
Hypersensitivity pneumonitis
Extrinsic allergic alveolitis
Immunologically mediated disease from repeated inhalation and sensitization to organic dusts
Acute (cough, fever, chills, and malaise last 18-24hrs), subacute and chronic forms (constant exposure leading to progressive fibrosis)
Etiology: bacteria (Farmer’s lung), fungi/mold, animal protein (bird droppings, urine), etc.
PE: diffuse crackles, fever, cough
CXR: nonspecific fibrosis and infiltrates
Diagnosis: Respiratory sxs that worsen in certain environments, antibodies against offending agent, environmental challenge
Treatment: Eliminate exposure, corticosteroids
Collagen Vascular Disease
Most collagen vascular diseases involve the lung
Examples:
- SLE
- Scleroderma
- RA
- Sjogren’s syndrome
Manifestations:
- Pulmonary fibrosis
- Pneumonitis
- Pleural effusions
- Pulmonary HTN
Treat underlying disease
Drug Induced ILD
Mechanism:
- Direct injury
- Hypersensitivity response
Physical exam:
- Fever, crackles, pleural rub
CXR: diffuse migratory infiltrates, pulmonary edema
Lab: restrictive pattern PFTs
Manifestations: depends on different drugs
- pneumonitis
- fibrosis
- BOOP
- ARDS
- pulmonary edema
Examples of drugs that cause pulmonary toxicity
Bleomycin (chemo)
Antimicrobials: nitrofuratoin, sulfasalazine
Amiodarone, flecanide, tocainide, procainamide
Illicit drugs
Aspirin
Microwave popcorn
Pulmonary vasculitis
Characterized by the destruction of blood vessels
Etiologies:
- Wegener’s granulomatosis
- Chrug-Strauss syndrome
- Lymphomatoid
- Wegener’s granulomatosis
Diagnosis: lung biopsy, evaluate underlying disease
Sarcoidosis
Pathology: non-caseating granulomas
Etiology: unkown
Epidemiolgy:
- MC in blacks in US
- ages 20-40
- MC in women
Pulmonary involvement:
- dyspnea, cough, wheezing, hemoptysis, laryngeal and bronchial lesions
- CXR: hilar adenopathy, pulmonary fibrosis
- PFTs: restrictive
Systemic organ involvement:
- general: fever, malaise, weight loss
- derm: erythema nodosum
- ocular, neuro, rheumatologic, GI, cardio, hematologic, endo, renal involvement
Diagnosis: lung or hilar node biopsy, biopsy of other organs involved
Treatment: corticosteroids
Pulmonary Infiltrates with eosinophilia
(PIE or Loffler’s Syndrome)
Mild disease with transient pulmonary infiltrates and blood eosinophilia
Clinical presentation:
- CXR
- WBC
- test for aspergellosis (fungal infection that can be associated w/ PIE)
Radiation lung damage
Etiology: radiation therapy for cancer
Sxs: fever, dyspnea
PE: crackles
CXR: infiltrates-focal or diffuse; fibrosis within radiation field
Rare lung disease
Histiocytosis X
- proliferation of langerhans cells
- associated with smoking
Lymphangioleiomyomatosis
- premenopausal women
- proliferation of smooth muscles in walls of lymphatics and venules
- spontaneous pneumothorax, infiltrates, pleural effusions
- accelerated during pregnancy
