Idiopathic Pulmonary Fibrosis (IPF) Clinical Presentation

Updated: Jul 16, 2021
  • Author: Alaa Abu Sayf, MD; Chief Editor: Guy W Soo Hoo, MD, MPH  more...
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Presentation

History

The clinical symptoms of idiopathic pulmonary fibrosis (IPF) are nonspecific. Most patients present with exertional dyspnea and a nonproductive cough. Such symptoms can be shared with a variety of pulmonary and cardiac diseases. Dyspnea, which is the most prominent symptom in idiopathic pulmonary fibrosis, usually begins insidiously and is often progressive. Associated systemic symptoms can occur but are not common. Some of these systemic symptoms include weight loss, low-grade fevers, fatigue, arthralgias, or myalgias.

The reported median duration of symptoms before the diagnosis of idiopathic pulmonary fibrosis is established is one to two years. [12] Most patients are referred to a cardiologist for evaluation of exertional dyspnea prior to being referred to a pulmonologist. Approximately 5% of patients have no presenting symptoms when idiopathic pulmonary fibrosis is diagnosed. Among asymptomatic patients with idiopathic pulmonary fibrosis (diagnosed by radiographic abnormalities found on routine chest radiograph screening and lung biopsy showing usual interstitial pneumonia), symptoms developed approximately 1000 days after the recognition of the radiographic abnormality. [12]

It is critical to obtain a complete history, including medication history, drug use, social history, occupational, recreational, and environmental respiratory exposure history, risk factors for human immunodeficiency virus infection, and review of systems, to ensure other causes of interstitial lung disease are excluded. Amiodarone, bleomycin, and nitrofurantoin are notable medications associated with pulmonary fibrosis. Oxidant stress from smoking may damage alveolar epithelial cells and contribute to the pathogenesis of idiopathic pulmonary fibrosis. [36] Any patient with idiopathic pulmonary fibrosis who is a current smoker should be encouraged to quit. Any prior exposure to asbestos, silica, heavy metals, contaminated ventilation systems, moldy foliage, and/or pigeon droppings should be investigated. Evidence of arthralgia, arthritis, photosensitivity, Raynaud phenomenon, dry eyes, and/or dry mouth on review of systems may indicate the presence of a collagen-vascular disease.

Physicians should pay attention to historical clues that may suggest the presence of obstructive sleep apnea (OSA) because a 2009 study demonstrated the high prevalence of OSA in patients with idiopathic pulmonary fibrosis. Fifty outpatients with stable idiopathic pulmonary fibrosis were prospectively evaluated for the presence of OSA. OSA was defined as an apnea-hypopnea index (AHI) of greater than 5 events per hour. Ten subjects (20%) had mild OSA (AHI of 5-15 events per hour) and 34 subjects (68%) had moderate-to-severe OSA (AHI of >15 events per hour). [37] Therefore, the prevalence of OSA in this sample was 88%, suggesting that OSA in patients with idiopathic pulmonary fibrosis may have been previously underrecognized.

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Physical Examination

In most patients with idiopathic pulmonary fibrosis (IPF), the physical examination reveals fine bibasilar inspiratory crackles (Velcro crackles). Additionally, digital clubbing is seen in 25-50% of patients with idiopathic pulmonary fibrosis. [12] Extrapulmonary involvement does not occur with idiopathic pulmonary fibrosis, and, therefore, physical examination findings do not help to confirm the diagnosis.

Pulmonary hypertension is a common comorbidity in patients with idiopathic pulmonary fibrosis, and an estimated 20-40% of patients with idiopathic pulmonary fibrosis who are evaluated or listed for lung transplantation have pulmonary hypertension at rest. [4] Physical examination findings may be suggestive of the presence of pulmonary hypertension. Patients may have a loud P2 component of the second heart sound, a fixed split S2, a holosystolic tricuspid regurgitation murmur, and pedal edema. As right ventricular hypertrophy ensues, a right ventricular heave may be palpated at the lower left sternal border and increased right atrial pressure may cause elevation of the jugular venous pressure. [5]

A summary of possible symptoms is as follows:

  • Dry cough
  • Fatigue
  • Dyspnea (particularly during or after physical activity)
  • Digital clubbing
  • Weight loss
  • Leg edema
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Complications

The following are complications that can be seen in patients with idiopathic pulmonary fibrosis (IPF):

  • Pulmonary hypertension

  • Acute exacerbation of pulmonary fibrosis

  • Respiratory infection

  • Acute coronary syndrome

  • Thromboembolic disease

  • Adverse medication effects

  • Lung cancer

Complications and mortality

Idiopathic pulmonary fibrosis carries a poor prognosis, with a median survival of 3.8 years among adults aged 65 years or older in the United States. Although this statistic is disappointing, in practice it is not uncommon for patients to live 5 years or more after receiving the diagnosis. Many patients die from progressive, chronic hypoxemic respiratory failure. Palliative care is rarely instituted in patients with idiopathic pulmonary fibrosis before the end of life. Each year, approximately 10-20% of patients with idiopathic pulmonary fibrosis have an acute exacerbation, characterized by worsened hypoxemic respiratory failure, with bilateral ground-glass opacities, consolidation, or both on HRCT imaging that are not fully explained by volume overload. Exacerbations may be triggered by a clinical event (eg, infection, aspiration, drug toxicity) but are frequently idiopathic. Most patients with an acute exacerbation die from acute respiratory failure. Available guidelines make weak recommendations for the use of glucocorticoids and do not recommend the use of mechanical ventilation in patients with an acute exacerbation, emphasizing the need to establish physician orders regarding life-sustaining treatment before the onset of a life-threatening event.

Patients with idiopathic pulmonary fibrosis are at increased risk for venous thromboembolism, lung cancer, and pulmonary hypertension. [38, 39, 40] A high index of suspicion should be maintained for pulmonary embolism as the cause of any acute respiratory deterioration. Incidental pulmonary nodules should be managed according to established guidelines for high-risk patients. Annual low-dose CT scanning should be considered for patients meeting the US Preventive Services Task Force criteria for lung cancer screening.

Although pulmonary hypertension occurs in some patients with idiopathic pulmonary fibrosis, management in the outpatient setting should consist solely of supplemental oxygen, without pulmonary vasodilator therapy. Until further data are available, targeted therapies approved for pulmonary arterial hypertension should be avoided in patients with idiopathic pulmonary fibrosis unless they are enrolled in a clinical trial investigating such therapies.

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