What does the term "bronchodilator response" refer to in pulmonary function testing?

The term "bronchodilator response" specifically refers to the improvement in lung function following the administration of a bronchodilator. In pulmonary function testing, this is measured by assessing changes in forced expiratory volume in one second (FEV1) or other pulmonary function metrics before and after the bronchodilator is given. A significant increase in these parameters indicates that the airways are responsive to the medication, which is particularly relevant in conditions like asthma or chronic obstructive pulmonary disease (COPD).

This concept helps determine how much constriction of the airways can be reversed with medication, providing insight into the underlying pathophysiology of the patient’s respiratory condition.