Bronchodilator Response Calculator
The change in FEV₁ (or FVC) after a bronchodilator, against the classic 12% and 200 mL reversibility threshold.
Written by Apex Respiratory Editorial Team
Enter the pre- and post-bronchodilator values to calculate the response.
Reading reversibility honestly
The classic ATS/ERS 2005 criterion calls a response significant when FEV₁ or FVC rises by at least 12% and at least 200 mL from the pre-bronchodilator baseline. Enter the pre and post values for whichever parameter you are testing.
A significant response supports reversible obstruction (asthma), but a negative test does not exclude it — correlate with the whole clinical picture. Note the 2022 ATS/ERS update redefined a significant response as a change greater than 10% of the predicted value.
Educational use only. This material supports respiratory therapy education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional protocols, or physician orders. Always follow facility policies and current provider orders, and verify calculations independently before clinical use.
Sources
- Pellegrino R, Viegi G, Brusasco V, et al. Interpretative strategies for lung function tests. Eur Respir J. 2005;26(5):948-968.
- Kacmarek RM, Stoller JK, Heuer AJ. Egan's Fundamentals of Respiratory Care. 12th ed. Elsevier; 2021. Pulmonary function testing chapters.