Which clinical manifestation is characteristic of both emphysema and chronic bronchitis?

Prolonged expiration is indeed a clinical manifestation characteristic of both emphysema and chronic bronchitis. In both conditions, airflow obstruction leads to difficulty with expiration. In emphysema, the destruction of alveolar walls results in loss of elastic recoil, making it hard for individuals to exhale fully. This leads to air trapping in the lungs and prolonged expiration as the small airways collapse during exhalation.

In chronic bronchitis, inflammation and mucus production cause airway narrowing, which also contributes to prolonged expiration. The increased resistance in the airways during forced expiration means that it takes longer for air to be expelled from the lungs.

While barrel chest and hypercapnia can occur in emphysema due to the over-inflated lungs, and excess mucus production is a hallmark of chronic bronchitis, prolonged expiration is an effect that is commonly shared in the pathophysiology of both diseases. Therefore, prolonged expiration serves as a clear link between the two conditions in terms of their impact on respiratory function.