9/15- Interstitial Lung Disease Flashcards
What are the components of the pulmonary interstitium?
- Alveolar epithelium
- Pulmonary capillary endothelium
- Basement membrane
- Perivascular and perilymphatic tissues
What does ILD refer to?
Interstitial Lung Diseases
- Diffuse Parenchymal Lung Disorders
- Heterogeneous group of disorders grouped together due to similar clinical, physiologic, radiographic, and pathologic features
May be classified by:
- Known causes or unknown causes
- Based on histo-pathology: alveolitis/fibrosis or granulomatous or alveolar filling
- Based on onset: acute or chronic
Flowchart classification of diffuse parenchymal lung disease
- Known cause (drugs, collagen vascular dz…) - Idiopathic interstitial pneumonia
- Idiopathic pulmonary fibrosis
- IIP other than idiopathic pulmonary fibrosis (different pneumonias)
- Granulomatus DPLD (sarcoidosis)
- Other forms of DPLD
Diagnostic approach to ILD diagnosis?
Multidisciplinary Clinical + Radiology + Pathology
Typical presentation of ILD
- Age
- Gender
- Symptoms
- Typ > 50 yo
- Mostly women > men EXCEPT rheumatoid arthritis and IPF
Symptoms:
- Progressive dyspnea
- Dry cough
- Occ. weight loss
What are some ILDs with acute onset (days-weeks)?
- AIP (Hamman-Rich Syndrome)
- Acute pneumonitis from collagen vascular disease (especially SLE)
- Cryptogenic organizing pneumonia
- Drugs
- Diffuse alveolar hemorrhage
- Eosinophilic lung disease
- Hypersensitivity pneumonitis
What are some ILDs with subacute onset (weeks - months)?
- Collagen vascular disease-associated ILD
- Cryptogenic organizing pneumonia
- Drugs
- Subacute hypersensitivity pneumonitis
What are some ILDs with chronic onset (months - years)?
- IPF, NSIP, and other IIPs
- Pneumoconioses (lung disorders caused by occpational disorders)
- Chronic hypersensitivity pneumonitis
- Collagen vascular disease-associated ILD
What illness are associated with ILDs that you might expect to find in past medical history?
- Collagen vascular disorders
- Rheumatoid arthritis
- SLE
What diseases might be expected in family history for someone with ILD?
- Sarcoidosis
- Interstitial pulmonary fibrosis
What medication history might you find for someone with ILD?
MANY
- Methotrexate
- Amiodarone
- Also some illicit drugs
What might you look for in the social history of someone with ILD?
- Occupation: ship-building (demolition– asbestos), insulator, sand-blasting (silica exposure), farming
- Smoking history: IPF, RB-ILD, DIP
(RB-ILD so associated that it may get better upon smoking cessation)
What might be expected in the physical exam for someone with ILD?
Most findings from auscultation
- Tachypnea
- Rales (“Velcro” crackles)*
- Clubbing
- Exercise desaturation
Late stages:
- Signs of right heart failure
- Cyanosis
What labs might you find for someone with ILD?
- ABG
- Certain disease disorder labs
- Others
ABG
- Early stages: no changes
- Late stages: hypoxemia; elevated A-a gradient
Connective tissue disorder labs:
- ANA
- Rheumatoid factor
Others:
- ACE and Ca elevated in Sarcoidosis
Describe pulmonary function tests for patients with ILD?
- FEV1/FVC
- TLC
- DLCO
Restrictive pattern
- Decreased lung volumes; TLC reduction determines severity of disease
- Normal FEV1/FVC
Reduced DLCO (diffusion capacity) secondary to physiological alveolar-capillary block
T/F: PFT can help determine specific disease/etiology of ILD?
False
What are the radiologic patterns of ILD?
- Reticular: fine lines due to thickening and fibrosis of interstitium
- Nodular
- Reticulo-nodular
- Ground glass: hazy; can see through it, but somewhat obscure (more in acute-onset ILDs)
- Alveolar
What conditions fall into the following radiologic patterns of ILD:
- Reticular
- Nodular
- Reticulo-nodular
- Ground glass
- Alveolar
Reticular
- IPF (idiopathic pulmonary fibrosis)
- Asbestosis
- Connective-tissue associated
Nodular
- Sarcoidosis
- Silicosis
- Hypersensitivity
- Pneumonitis
Reticulo-nodular
Ground glass
- NSIP (nonspecific interstitial pneumonia)
- DIP (desquamative interstitial pneumonia)
- RBILD (respiratory bronchiolitis interstitial lung dz)
- Pulmonary hemorrhage
Alveolar
- Cryptogenic organizing pneumonia