What pulmonary function test (PFT) measurement best indicates reversible airway obstruction in response to inhaled bronchodilators?

The measurement that best indicates reversible airway obstruction in response to inhaled bronchodilators is FEV1, or Forced Expiratory Volume in one second. This specific measure assesses how much air a person can forcibly exhale in the first second of a breath. In the context of bronchospasm or conditions like asthma, the FEV1 value can be significantly decreased due to narrowing of the airways.

When a bronchodilator is administered, a substantial increase in FEV1 indicates that there is reversible airway obstruction, meaning the airways can open up with medication. This response helps in diagnosing and characterizing conditions such as asthma and can also indicate the severity of the obstruction.

Other measurements, while useful in pulmonary function testing, do not specifically target the reversibility aspect as effectively. For instance, FVC (Forced Vital Capacity) measures the total amount of air forcefully exhaled but doesn’t focus on the timing of the airway opening. PEF (Peak Expiratory Flow) provides a quick assessment of airflow but is not as sensitive as FEV1 for detecting obstructive changes. VC (Vital Capacity) measures the total volume of air exhaled after a deep breath but, like FVC, does not specifically assess