Interstitial Lung Disease (restrictive)
• Inflammatory process involving the alveolar wall (resulting in widespread fibroelastic • proliferation and collagen deposition).
• Can lead to irreversible fibrosis, distortion of the lung architecture, and impaired gas exchange.
• Prognosis is very variable and depends on diagnosis.
• Ask about medication history (esp. chemotherapeutic agents, gold, amiodarone, penicillamine, and nitrofurantoin)
• Previous jobs (exposure to asbestos, silicone, beryllium, and coal).
• Rales at the bases are common, digital clubbing is common (esp. in idiopathic pulmonary fibrosis), signs of pulmonary HTN and cyanosis in advanced disease.
• Dyspnea (at first with exertion then at rest), cough (nonproductive), fatigue, symptoms secondary to another condition.
• CXR, CT, PFTs, oxygen desaturation during exercise.
• Bronchoalveolar lavage for culture and cytology yields variable results.
• Tissue biopsy is often required and can be done via fiberoptic bronchoscopy with transbronchial biopsy (limited utility), open lung biopsy, or video-assisted thoracoscopic lung biopsy (VATS).
• UA can show signs of glomerular injury in Goodpasture's or Wegener's.
• Coal worker's pneumoconiasis, silicosis, asbestosis, berylliosis.
• Sarcoidosis (along with other organ involvement), Wegener's granulomatosis, Churg-Strauss syndrome.
Alveolar Filling Disease
• Goodpasture's syndrome, Idiopathic pulmonary hemosiderosis, alveolar proteinosis.
• Hypersensitivity pneumonitis, eosinophilic pneumonitis.
• Amiodarone, nitrofurantoin, bleomycin, phenytoin, illicit drugs.
• Idipathic pulmonary fibrosis, bronchiolitis obliertans organizing penumonia (BOOP), ILD associated with connective tissue disorders (RA, scleroderma, SLE, mixed connective tissue disease), ARDS, infection (fungal, TB, viral pneumonia), radiation pneumonitis.
• Typical diffuse changes are noted (reticular, reticulonodular, ground glass, honeycombing).
• Honeycombing refers to a scarred shrunken lung and is an end-stage finding with poor prognosis. Air spaces are dilated and there are fibrous scars in the interstitial. Can arise from many causes of ILD.
Pulmonary Function Tests
• A restrictive pattern. FEV1/FVC is increased >80%. Both FEV1 and FVC are low. Decreased DLCO. Decreased TLC and RV.
• Shows the extent of fibrosis better than other imaging. Fibrosis, honeycombing, or traction bronchiectasis.