Assessing IPF Symptoms
Reprinted with permission of the American Thoracic Society. Copyright © 2014 American Thoracic Society. Raghu G, Collard HR, Egan JJ, et al. An official ATS/ERS/JRS/ALAT statement: idiopathic pulmonary fibrosis: evidence-based guidelines for diagnosis and management. Am J Respir Crit Care Med. 2011;183:788-824. Official Journal of the American Thoracic Society. Note: this document was published in 2011 and is currently in revision. Certain aspects of this document may be out of date and caution should be used when applying these in clinical practice or other usages.
Acute Exacerbations of IPF
Acute exacerbations of IPF (AE-IPF) are defined as an acute (within 30 days) worsening of dyspnea, presence of newly developed radiologic abnormalities, and exclusion of other causes of breathlessness in a patient with a previous or concurrent diagnosis of IPF.21 The typical evaluation of patients with suspected AE-IPF includes exclusion of alternative causes of breathlessness such as:22
- Left heart failure
- Pulmonary hypertension with or without right heart failure (cor pulmonale)
- Respiratory infection
- Other causes of acute lung injury (medication toxicity, blood product transfusion, pancreatitis)
AE-IPF are clinically significant as irreversible, accelerated disease progression can occur.8 In addition, AE-IPF often result in death.8 Furthermore, AE-IPF often occur without warning or an identifiable preceding event, and all patients with IPF are susceptible, regardless of disease severity.19
Various studies have demonstrated the clinical significance of AE-IPF, particularly as it relates to incidence and impact on mortality. Approximately 20% of IPF patients will have AE-IPF within 3 years of diagnosis,89 which is associated with a poor prognosis. The median survival from onset of AE-IPF was just 2.2 months in one study; moreover, 50% of patients admitted with AE-IPF do not survive to hospital discharge. The prognosis of patients admitted to an intensive care unit was even worse, with 80% of these patients dying.8
In the absence of another identifiable cause, AE-IPF is indicative of disease progression in IPF.1 Therefore, identification of these events in clinical practice is important. Diagnostic criteria for AE-IPF have been described and are useful for assessing patients with IPF. Table 1 outlines the proposed criteria for diagnosing AE-IPF.19 For more information about AE-IPF, see Natural History and Potential Risk Factors.
|Previous or concurrent diagnosis of idiopathic pulmonary fibrosisa|
|Unexplained worsening or development of dyspnea within 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 patternb|
|No evidence of pulmonary infection by endotracheal aspirate or bronchoalveolar lavagec|
|Exclusion of alternative causes, including the following:
aIf the diagnosis of idiopathic pulmonary fibrosis is not previously established according to American Thoracic Society/European Respiratory Society consensus criteria,1 this criterion can be met by the presence of radiologic and/or histopathologic changes consistent with usual interstitial pneumonia pattern on the current evaluation.
bIf no previous HRCT is available, the qualifier “new” can be dropped.
cEvaluation of samples should include studies for routine bacterial organisms, opportunistic pathogens, and common viral pathogens.
dCauses of acute lung injury include sepsis, aspiration, trauma, reperfusion pulmonary edema, pulmonary contusion, fat embolization, inhalational injury, cardiopulmonary bypass, drug toxicity, acute pancreatitis, transfusion of blood products, and stem cell transplantation.
Content contributed by:
Ryan Hadley, MD
University of Michigan