TABLE 1

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

	Current	Proposed
Definition	An idiopathic acute respiratory worsening in a patient with IPF	An acute respiratory worsening characterised by diffuse alveolar damage in a patient with IPF
Diagnostic criteria	Previous or concurrent diagnosis of IPF	Previous or concurrent diagnosis of IPF
	Unexplained worsening or development of dyspnoea within the past 30 days	Acute 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 pattern	HRCT with new bilateral ground-glass abnormality with or without consolidation
	No evidence of pulmonary infection by endotracheal aspirate or bronchoalveolar lavage	Clinical presentation consistent with diffuse alveolar damage
	Exclusion of alternative causes, including left heart failure, pulmonary embolism and an identifiable cause of acute lung injury