What are the expected findings in a patient with emphysema?

In patients with emphysema, the expected findings include increased residual volume and a reduced forced expiratory volume in one second to forced vital capacity (FEV1/FVC) ratio. Emphysema is characterized by the destruction of the alveolar walls, which leads to the enlargement of the air spaces and a decrease in the surface area available for gas exchange. As a result, patients experience difficulty in expelling air from the lungs, which causes air trapping and increases the residual volume.

The reduction in the FEV1/FVC ratio is a hallmark of obstructive lung diseases like emphysema. In this condition, the FEV1 is significantly lower due to the obstructed airflow during expiration, while the forced vital capacity (FVC) may remain relatively normal or be less reduced than FEV1, hence leading to a decreased ratio. This distinguishes emphysema from restrictive lung diseases, where both FEV1 and FVC are reduced but maintain a normal or increased ratio.

In contrast, the other options do not accurately reflect the physiological changes seen in emphysema. For instance, while airway resistance is a factor, bronchoconstriction is not a primary feature of emphysema. Normal lung volumes with wheezing may occur but