What is the expected result of a bronchodilator study in a patient with restrictive lung disease?

In patients with restrictive lung disease, the anticipated response to bronchodilator therapy is typically no change in FEV1. This is primarily because restrictive lung diseases, such as pulmonary fibrosis or sarcoidosis, are characterized by reduced lung volume due to stiffening of the lung tissue or restriction of the lung expansion. The primary defect in these diseases is a limitation in lung expansion rather than airway obstruction, which means that the pathways for airflow are generally not obstructed to the degree seen in obstructive diseases like asthma or COPD.

When a bronchodilator is administered, it primarily works to relax the smooth muscle in the airways, which can open up constricted air passages and is particularly effective in obstructive lung diseases. However, in restrictive lung diseases, the issue is not related to bronchial constriction, so the bronchodilator does not produce a significant change in airflow measurements such as FEV1.

Other choices reflect aspects of lung function that do not relate to the expected outcome of a bronchodilator study in restrictive lung disease. For example, increased FEV1 would suggest improvement in airflow which is not characteristic of restrictive lung disease. Decreased FVC indicates a reduction in total lung volume, which is a hallmark of restrictive diseases, but