Acute Exacerbation of Idiopathic Pulmonary Fibrosis Diagnosis and Management

Diagnostic Criteria

The European Respiratory Society recommends that acute exacerbation of IPF be diagnosed when there is recent worsening of dyspnea (<30 days) with new ground-glass opacities on imaging, after excluding other causes of respiratory deterioration 1, 2
Acute exacerbation of IPF is characterized by acute (<30 days) worsening of dyspnea with no identified cause in a patient with established IPF 1, 2
HRCT shows new opacities (particularly ground-glass opacities) in addition to pre-existing fibrotic abnormalities 1, 2
Worsening hypoxaemia is common (≥10 mmHg decrease in oxygen levels) 2
Diagnostic workup must rule out alternative causes of acute deterioration before confirming acute exacerbation 1, 2

The European Respiratory Society recommends high-dose corticosteroids as first-line treatment despite limited evidence from controlled trials 1, 2, 3
High-dose corticosteroids may be used, but no specific recommendations exist regarding dose, route, and duration 1, 2, 3
Immunosuppressive agents, such as intravenous cyclophosphamide, may be considered as an adjunctive treatment 1, 2
Anticoagulation may be prescribed if thromboembolic venous disease is suspected 2
Wide-spectrum antibiotics may be used when infection has not been definitely ruled out 2

Invasive ventilation is not recommended in patients with established IPF and acute respiratory failure due to high associated mortality 1, 2, 4
Non-invasive ventilation may be preferred to invasive ventilation in some patients with acute exacerbation 2, 4
Oxygen therapy should be provided to maintain adequate oxygenation 5

Pulmonary rehabilitation may be considered in stable patients but may not be feasible during acute exacerbation 1, 6
Lung transplantation should be considered in eligible patients (typically <65 years of age) 1, 6

Annual influenza vaccination and pneumococcal vaccination are recommended 6
Early consideration of lung transplantation in eligible patients with IPF is recommended 6

Video-assisted surgical lung biopsy is usually considered too hazardous during acute exacerbation and is not recommended 2
Discussions regarding goals of care, including decisions about mechanical ventilation, should ideally occur during stable clinic visits before an acute exacerbation 2, 3

Elevated procalcitonin and C-reactive protein levels can help differentiate between infectious and non-infectious acute exacerbation of ILD, with elevated procalcitonin suggesting bacterial infection, according to the American Thoracic Society 7
Consider bronchoalveolar lavage (BAL) for culture, viral PCR, and fungal studies if diagnosis remains uncertain, as recommended by the American Thoracic Society 7
Elevated procalcitonin (>0.5 ng/mL) suggests bacterial infection, as indicated by the American Thoracic Society 7
Normal or mildly elevated inflammatory markers (CRP elevated but procalcitonin normal) may indicate non-infectious exacerbation, according to the American Thoracic Society 7

Neutrophil predominance (>3%) is common in IPF but does not distinguish infectious from non-infectious causes, as noted by the American Thoracic Society 7
Lymphocytosis may suggest hypersensitivity pneumonitis or organizing pneumonia rather than typical acute exacerbation, according to the American Thoracic Society 7
Positive BAL cultures definitively indicate infection, as indicated by the American Thoracic Society 7

Diffuse, bilateral ground-glass opacities without lobar predominance may indicate non-infectious exacerbation, as suggested by the American Thoracic Society 8