PT  - JOURNAL ARTICLE
AU  - Matthew J Hegewald
AU  - Ryan G Townsend
AU  - Jaron T Abbott
AU  - Robert O Crapo
TI  - Bronchodilator Response in Patients With Normal Baseline Spirometry
AID  - 10.4187/respcare.01537
DP  - 2012 Oct 01
TA  - Respiratory Care
PG  - 1564--1570
VI  - 57
IP  - 10
4099  - http://rc.rcjournal.com/content/57/10/1564.short
4100  - http://rc.rcjournal.com/content/57/10/1564.full
AB  - BACKGROUND: Spirometry before and after bronchodilator is performed to assess air flow-limitation reversibility. In patients with normal baseline spirometry the frequency of a positive bronchodilator response, as defined by American Thoracic Society/European Respiratory Society criteria, has not been described. METHODS: We retrospectively analyzed adult patients tested in 2 academic pulmonary function testing laboratories over a 7-year period, with specific attention to patients who underwent bronchodilator testing after a normal baseline spirometry (FEV1, FVC, and FEV1/FVC within normal limits). The frequency of a positive response to bronchodilator, defined as a 12% and 200 mL increase in either FEV1 or FVC, was calculated and associated with demographic factors. RESULTS: Of the 1,394 patients with normal spirometry who were administered bronchodilator, 43 (3.1%) had a positive response. The percent of patients responding to bronchodilator were grouped according to pre-bronchodilator FEV1: > lower limit of normal to 90% of predicted = 6.9%, 90–100% of predicted = 1.9%, and > 100% of predicted = 0%. An FEV1/FVC in the lowest 2 quartiles was associated with a higher frequency of bronchodilator response. Older patients were more likely to respond to bronchodilator, but no other demographic factors were associated with a positive bronchodilator response. CONCLUSIONS: In our study population the frequency of a positive bronchodilator response in patients with normal baseline spirometry is 3.1%. None of the patients with a pre-bronchodilator FEV1 > 100% of predicted and only 1.9% of patients with an FEV1 between 90% and 100% of predicted responded. Bronchodilator testing can be omitted in patients with normal spirometry and an FEV1 above 90% of predicted, as they have a low probability of a positive response.