What percentage increase in forced expiratory volume indicates a positive response to a bronchodilator?

A positive response to a bronchodilator is typically defined by a significant increase in forced expiratory volume in one second (FEV1) after the administration of the medication. The standard threshold for this is usually a 12% increase in FEV1 along with an absolute increase of at least 200 mL. However, in some assessments, particularly for different settings or populations, a higher percentage may be used to indicate a clinically meaningful response.

In this case, a 22% increase in FEV1, as identified in the correct option, has clinical relevance and is often used in practice to assess the effectiveness of bronchodilator therapy. This percentage aligns with research and guidelines, where a response greater than 20% may reflect a genuine significant improvement in airway function, supporting the diagnosis of reversible airway obstruction, which is common in conditions like asthma and chronic obstructive pulmonary disease (COPD).

The choice of 22% marks a clear distinction in clinical assessments, ensuring that the increase reflects more than just variability but rather a considerable change that indicates therapeutic efficacy of the bronchodilator used.