Current and proposed definitions and diagnostic criteria for acute exacerbations of idiopathic pulmonary fibrosis (IPF)

DefinitionAn idiopathic acute respiratory worsening in a patient with IPFAn acute respiratory worsening characterised by diffuse alveolar damage in a patient with IPF
Diagnostic criteriaPrevious or concurrent diagnosis of IPFPrevious or concurrent diagnosis of IPF
Unexplained worsening or development of dyspnoea within the past 30 daysAcute worsening of dyspnoea from a parenchymal cause (generally over <30 days)
HRCT with new bilateral ground-glass abnormality and/or consolidation superimposed on a background reticular or honeycomb pattern consistent with usual interstitial pneumonia patternHRCT with new bilateral ground-glass abnormality with or without consolidation
No evidence of pulmonary infection by endotracheal aspirate or bronchoalveolar lavageClinical presentation consistent with diffuse alveolar damage
Exclusion of alternative causes, including left heart failure, pulmonary embolism and an identifiable cause of acute lung injury
  • HRCT: high-resolution computed tomography.