What condition might cause increased interstitial pressure affecting pulmonary function?

Increased interstitial pressure is often associated with pulmonary edema, where fluid accumulates in the interstitial spaces of the lungs, leading to elevated pressures in these areas. This condition can significantly impair pulmonary function due to the interruption of the normal gas exchange process. Fluid in the interstitial space can prevent oxygen from adequately reaching the alveoli, thus reducing oxygenation of the blood and potentially leading to dyspnea and hypoxemia.

Pneumonia primarily involves inflammation and infection of the lung parenchyma, leading to consolidation of lung tissue rather than an increase in interstitial fluid pressure. Emphysema is characterized by the destruction of alveolar structure, causing decreased lung elasticity and airflow limitation without directly affecting interstitial pressures. Asthma involves bronchoconstriction and increased airway resistance, but it does not typically lead to elevated interstitial pressures.

Therefore, pulmonary edema is the condition that most accurately describes the mechanism of increased interstitial pressure and its adverse effects on pulmonary function.