Which condition is described as destruction of airways distal to the bronchioles, with involvement of the pulmonary capillary bed?

• A. Emphysema
• B. CHF
• C. RSV
• D. TB

Answer: (A)

Destruction of the alveolar walls and the tiny capillary network around them is the hallmark here. Emphysema involves damage to structures distal to the bronchioles, specifically the alveoli, which also takes out much of the pulmonary capillary bed that lies within those walls. This collapse of the small airways and loss of surface area for gas exchange leads to air trapping, enlarged air spaces, and reduced diffusion capacity, all classic features of emphysema.

The other conditions don’t fit this pattern. Congestive heart failure mainly causes fluid buildup and edema in the lungs rather than destruction of alveolar walls. RSV is a viral infection that inflames and narrows small airways (bronchiolitis) but does not cause the structural destruction of alveolar walls and capillaries. TB causes granulomatous inflammation and may cavitate, but it isn’t characterized by diffuse destruction of distal airways with involvement of the capillary bed.

So the description points to emphysema.