Which parameter is primarily used to measure improvement following bronchodilator treatment?

The parameter primarily used to measure improvement following bronchodilator treatment is FEV1, or forced expiratory volume in one second. This measurement assesses how much air a patient can forcibly exhale in the first second of a bellow test. FEV1 is particularly sensitive to changes in airflow obstruction, especially in conditions like asthma or chronic obstructive pulmonary disease (COPD).

After bronchodilator therapy, a significant increase in FEV1 indicates that the medication is effectively opening the airways, thus improving the patient's airflow and overall lung function. Tracking these changes allows healthcare providers to evaluate the effectiveness of the treatment and make necessary adjustments to the management plan.

Other parameters such as PEF (peak expiratory flow) and FVC (forced vital capacity) also provide valuable information about lung function, but FEV1 is the most widely accepted measure for assessing immediate changes in airflow following bronchodilator therapy. RV (residual volume) measures the amount of air remaining in the lungs after a full exhalation and is not directly relevant to acute bronchodilator response evaluation.