In a patient with asbestosis, which of the following values would you expect to see a decrease in?

In patients with asbestosis, a decrease in Functional Residual Capacity (FRC) is expected. Asbestosis is a form of pneumoconiosis caused by asbestos exposure, leading to pulmonary fibrosis. This fibrotic process stiffens the lung tissue, decreasing lung compliance, which in turn affects various lung capacities.

FRC, which is the volume of air remaining in the lungs at the end of passive expiration, can decrease due to the restrictive lung disease characteristics of asbestosis. The stiffened lung tissue makes it difficult for patients to fully expand their lungs, thus reducing the volume of air left after exhalation. While other values like Inspiratory Capacity (IC), Forced Expiratory Volume in one second (FEV1), and Peak Expiratory Flow (PEF) may also change, the direct impact of pulmonary fibrosis and resulting lung compliance primarily leads to a significant decrease in FRC.

In restrictive lung diseases like asbestosis, the main characteristic is a reduction in lung volumes, making diminished FRC a hallmark finding during pulmonary function testing.