PANCE Blueprint Pulmonary (9%)

Patient will present as → a 67-year-old male with a 6-month history of progressive shortness of breath on exertion and a persistent dry cough. He has a past medical history of hypertension, controlled with medication, and a 30-pack-year smoking history, although he quit smoking 10 years ago. He denies any significant occupational exposures or a family history of lung disease. On examination, he appears tachypneic with a respiratory rate of 22 breaths per minute. Auscultation of the lungs reveals bilateral fine inspiratory crackles at the lung bases. His oxygen saturation on room air is 92%. Pulmonary function tests show a restrictive pattern with reduced forced vital capacity (FVC) and a preserved FEV1/FVC ratio. Diffusion capacity for carbon monoxide (DLCO) is significantly reduced. High-resolution computed tomography (HRCT) of the chest demonstrates bilateral reticular opacities, honeycombing, and traction bronchiectasis predominantly at the lung bases, without significant lymphadenopathy or pleural effusion. A diagnosis of Idiopathic Pulmonary Fibrosis is made. The patient is counseled about the nature of the disease, including its progressive course and the current lack of a cure. Treatment options, including antifibrotic therapy with nintedanib or pirfenidone to slow disease progression, are discussed. The importance of pulmonary rehabilitation, vaccinations, and supplemental oxygen therapy as needed is emphasized. The patient is also advised on lifestyle modifications, including regular exercise and smoking cessation support for his prior smoking habit. Referrals to a support group for patients with IPF and a palliative care consultation to manage symptoms and improve quality of life are provided.

Chronic progressive lung disorder characterized by increasing scarring, which ultimately reduces the capacity of the lungs; etiology unknown

• Idiopathic pulmonary fibrosis is the most common of all interstitial lung diseases
• In order to be considered "idiopathic," you must be sure to rule out other common causes, such as drugs and environmental or occupational exposures

Risk factors for IPF: older age (usually over 60), male sex, cigarette smoking (current or former), genetics or a family history of pulmonary fibrosis, and possibly GERD and chronic viral infections

Other causes of pulmonary fibrosis that must be ruled out before calling it "idiopathic":

• Connective tissue disease (rheumatoid arthritis, systemic sclerosis, myositis)
• Chronic hypersensitivity pneumonitis (birds, molds) and other environmental exposures
• Occupational dusts (asbestos, silica, hard metal dusts)
• Medications (methotrexate, amiodarone, nitrofurantoin, bleomycin, cyclophosphamide, rituximab)
• Radiation treatment

High-resolution CT (HRCT) is the key diagnostic test (a chest x-ray may show basilar reticular opacities but can be normal early)

• HRCT: usual interstitial pneumonia (UIP) pattern — basal, subpleural reticulation with honeycombing and traction bronchiectasis; a definite UIP pattern in the right clinical setting confirms IPF without a lung biopsy
• PFTs will demonstrate a restrictive pattern - the opposite of what you would see with asthma
  • Decreased total lung capacity, decreased forced vital capacity (FVC), decreased forced expiratory volume in one second (FEV1)
  • The FEV1/FVC ratio may be normal or greater than 80% (increased) due to a significant decrease in forced vital capacity (FVC)
  • DLCO is reduced (impaired gas exchange) — an early, sensitive finding

Pulmonary fibrosis induced by amiodarone.

HRCT in IPF: usual interstitial pneumonia (UIP) pattern with basal, subpleural honeycombing and traction bronchiectasis. Image: Yale Rosen, CC BY-SA 2.0

Treatment: antifibrotic drugs slow the decline in lung function (FVC) but do not cure IPF

• Nintedanib or pirfenidone = standard first-line; nerandomilast (an oral PDE4B inhibitor) is a newer FDA-approved option
• Supplemental oxygen for hypoxemia (resting SpO2 ≤88%), pulmonary rehabilitation, vaccinations, and smoking cessation
• Refer early for lung transplant evaluation — transplant can improve survival in eligible patients
• Do not use corticosteroids (or prednisone + azathioprine + N-acetylcysteine) for stable IPF — they do not help and can be harmful; steroids are reserved for acute exacerbations
• Most patients deteriorate; median survival is about 3–5 years from diagnosis