Idiopathic pulmonary fibrosis

Question 1

define idiopathic pulmonary fibrosis?

Answer 1

inflammatory condition of the lung resulting in progressive fibrosis of the alveoli and interstitium

Question 2

what is the pathophysiology of this condition?

Answer 2

• Recurrent injury to alveolar epithelial cells results in secretion of cytokines and growth factors
• This leads to fibroblast activation, recruitment, proliferation, differentiations into myofibroblasts and increased collagen synthesis and deposition

Question 3

risk factors of idiopathic pulmonary fibrosis?

Answer 3

o Smoking
o Occupational exposure to metal or wood dust
o Chronic microaspiration
o Animal and vegetable dusts

Question 4

what is the epidemiology of pulmonary fibrosis?

Answer 4

• More common in MALES

* Ages 50-70

Question 5

presenting symptoms of idiopathic pulmonary fibrosis?

Answer 5

• Gradual-onset, progressive dyspnoea on exertion
• Dry irritating cough
• Bi-basal fine end inspiratory creps
• Fatigue and weight loss are common

Question 6

signs of idiopathic pulmonary fibrosis?

Answer 6

• Clubbing (50%)

* Bibasal fine late inspiratory crackles

Question 7

what might the bloods show?

Answer 7

o ABG
• Normal in early disease
• PO2 decreases with exercise
• Normal PCO2, which rises in late stage disease
o ANA and Rheumatoid Factor
• 1/3 of patients are positive for ANA, 1/10 positive for RF

Question 8

what might a chest xray show?

Answer 8

• Early disease may show bilateral ground glass shadowing

- late disease eventually, honeycombing

Question 9

what is the investigation of choice?

Answer 9

high res CT

Question 10

what might the lung function tests show?

Answer 10

Restrictive features:
o reduced FEV1 and FVC
o with preserved or increased FEV1/FVC
o Impaired gas exchange (reduced TLCO)