In patients with COPD, which pulmonary function test results are expected?

In patients with Chronic Obstructive Pulmonary Disease (COPD), a hallmark of the condition is the obstruction of airflow due to inflammation and structural changes in the lungs. This obstruction primarily affects the expiratory phase of breathing, which is reflected in the results of pulmonary function tests.

A reduction in Forced Expiratory Volume in one second (FEV1) is typically observed in COPD patients, signifying the degree of airflow limitation. Alongside this reduction, Total Lung Capacity (TLC) and Residual Volume (RV) are often increased due to air trapping caused by the disease. The inability to fully exhale leads to retained air in the lungs, which explains why TLC and RV would be elevated.

This pattern of reduced FEV1 with increased TLC and RV is characteristic of obstructive airway diseases like COPD, distinguishing it from restrictive lung diseases where both FEV1 and TLC would be reduced and the FEV1/FVC ratio would change differently.

Thus, the correct interpretation of typical pulmonary function test results in COPD involves recognizing the associated increase in TLC and RV alongside the reduction in FEV1, as seen in the correct answer. This understanding is essential for accurate diagnosis, management, and treatment of COPD in clinical practice.