ILD (Raf)

Question 1

What is the differential diagnosis of a pulmonary hemorrhage?

Answer 1

• Pulmonary versus non-pulmonary (GI, sinus)
• Upper airway
• Lower airway (Bronchial circulation)–infection, bronchiectasis, neoplasm, foreign, vascular to bronchial tree fistula
• Alveolar focal–eg. pneumonia
• Diffuse alveolar–immune versus non-immune
• pulmonary vascular disease–>in particular, increased pulmonary venous pressure
• bleeding disorder
• trauma
  (Box 61.1 in Kendig’s for more details)

Question 2

Investigations for pulmonary hemorrhage?

Answer 2

• CT chest with contrast to look for PE, AVM
• Test for coagulation defects
• Bronchoscopy to look for foreign body, airway hemangioma, tumor, presence of hemosiderin laden macrophages
• Infection: blood and sputum cultures, TB testing with purified protein derivative
• If diffuse alveolar opacities—>echo to look for cardiac disease, CT with contrast, cardiac cath
• If systemic involvement (eg. renal disease, rash, joint disease)—>ANA, ANCA, CBC, ESR, CRP, urinalysis, metabolic panel, d-dimer, von willebrand factor, anti-phospholipid antibody, lupus anticoagulant
• If DAH and no cardiac, renal or systemic disease with negative antibodies (ANA, ANCA, anti-GBM)—>transthoracic biopsy either through open approach (mini-thoracotomy) or VATS

Question 3

What is orthodeoxia and what are some causes?

Answer 3

• Desaturation in oxygen saturation of >2-5% when moving from supine to upright
• Causes:
• pulmonary AVM (predilection for lower lobes)
• hepatopulmonary syndrome (since there are intrapulmonary vascular dilatations which are preferentially in dependent position)
• Inter-atrial shunt like PFO

Question 4

What is a pulmonary AVM?

Answer 4

Abnormal vessel, Direct connection between pulmonary artery and vein, without capillary bed in between
“aneurysmal”, dilated, tortuous
Usually 1 single arterial vessel and 1 single venous vessel