Acute conditions like ARDS largely affect which aspect of respiratory function?

Acute Respiratory Distress Syndrome (ARDS) primarily affects the diffusion capacity of the lungs. In ARDS, the alveoli—the tiny air sacs in the lungs—are filled with fluid and inflammatory cells, which significantly hinders the process of gas exchange. This condition reduces the surface area available for oxygen and carbon dioxide exchange, thereby impairing the ability of oxygen to diffuse from the alveoli into the bloodstream.

Understanding ARDS involves recognizing that while other aspects like airway resistance, compliance, and tidal volume may also be altered, the critical issue is the impaired gas exchange associated with compromised diffusion. Therefore, in this context, the diffusion capacity is the most directly affected component of respiratory function in patients suffering from ARDS.