Which statement about the exudative phase of ARDS is true?

• A. It is characterized by rapid fibrotic tissue formation.
• B. It involves pulmonary edema and atelectasis.
• C. It occurs after the reparative phase has completed.
• D. It is not associated with impaired gas exchange.

Answer: (B)

In ARDS, the exudative phase is the early injury period when the alveolar-capillary barrier is damaged, allowing protein-rich fluid to flood the alveolar spaces. This creates pulmonary edema and promotes collapse of affected alveoli, leading to atelectasis. The combination of edema, surfactant dysfunction, and hyaline membrane formation severely disrupts gas exchange, driving hypoxemia and stiff lungs.

That’s why the statement describing pulmonary edema and atelectasis fits the exudative phase best. The rapid formation of fibrotic tissue happens later in the reparative or fibrotic phase, not during the exudative stage. The exudative phase does not occur after the reparative phase has completed; it precedes and overlaps with early repair. And impaired gas exchange is a hallmark of this phase, not an absence of it.