Idiopathic pulmonary fibrosis

Background

• Median survival time 3 yrs after diagnosis
• Prevalence about 10-20 cases per 100,000 people
• Acute exacerbations carry mortality up to 80%
• 60% die from idiopathic pulmonary fibrosis, others die from:
  • VTE
  • Cardiovascular (ACS, CHF)
  • Infection

Clinical Features

• Diagnosis of exclusion
• Presentations with rapid deterioration without obvious cause commen
• May co-exist with pulmonary HTN and heart failure
• Diagnostic criteria for acute exacerbation of IPF:
  • Dx of IPF
  • Unexplained worsening of dyspnea within 30 days
  • Hypoxemia deviated from baseline ABG
  • No evidence of pulmonary infection
  • Exclusion of alternative causes (i.e. VTE)
  • CT with b/l ground-glass abnormalities/consolidation on a background reticular/honeycomb pattern c/w interstitial pneumonia
    • 100% have b/l ground-glass opacities
    • ~70% have consolidation

Diagnostics

• CBC, leukocytosis
• CRP elevated
• LDH elevated
• ABG with hypoxemia, hypercapnea
• EKG
• CXR with likely need for CT
• Echo to assess for pulm HTN, r/o CHF
• BAL in ICU to r/o infection

DDx

Pulmonary Fibrosis

• Interstitial pneumonias (acute, lymphocytic)
• Lung malignancy
• Aspiration pneumonia or pneumonitis
• Bacterial, viral, or fungal pneumonia
• Cryptogenic organizing pneumonia
• Interstitial lung disease associated with collagen vascular disease
• Drug-induced pulmonary toxicity (amiodarone, bleomycin, amphotericin B, carbamazepine, etc.)
• Eosinophilic granuloma (Histiocytosis X)
• Radiation pneumonitis
• Sarcoidosis
• Pneumoconiosis (Workplace exposure)
  • Asbestosis
  • Berylliosis
  • Chemical worker's lung
  • Coal worker's pneumoconiosis
  • Silicosis

See Also

• Pulmonary hypertension

Sources

• Bhatti H et al. Approach to acute exacerbation of idiopathic pulmonary fibrosis. Ann Thorac Med. 2013. Vol 8, Issue 2. Pg 71-77.
• Collard HR et al. Acute Exacerbations of Idiopathic Pulmonary Fibrosis. Am J Respir Crit Care Med. 2007 Oct 1; 176(7): 636–643.
• Ryerson CJ et al. Acute exacerbation of idiopathic pulmonary fibrosis: shifting the paradigm. Eur Respir J. 2015 Aug;46(2):512-20.
• Juarez MM et al. Acute exacerbation of idiopathic pulmonary fibrosis—a review of current and novel pharmacotherapies. J Thorac Dis. 2015 Mar; 7(3): 499–519.