What happens to capillary permeability during ARDS?

In Acute Respiratory Distress Syndrome (ARDS), one of the hallmark features is increased capillary permeability. This condition typically occurs due to various etiologies, such as sepsis, pneumonia, or trauma, which trigger inflammatory responses and disrupt the normal function of endothelial cells lining the capillaries in the lungs.

As a result of this increased permeability, fluid and protein leak from the intravascular space into the alveolar spaces. This accumulation of fluid in the alveoli impacts gas exchange, leading to the hallmark symptoms of ARDS, such as hypoxemia and respiratory distress. The progression of ARDS involves a further inflammatory response, resulting in edema and, ultimately, the formation of hyaline membranes in the alveoli, which further compromise lung function.

This choice accurately reflects the underlying pathophysiology of ARDS and its clinical manifestations, emphasizing the critical role of capillary permeability in the disorder.