Abstract
Extensively used current guidelines of the American Thoracic Society/European Respiratory Society (ATS/ERS) define a positive aerosolized bronchodilator (BD) response as: "...an increase in FEV(1) and/or FVC > or = 12% of control and > or = 200 mL." We hypothesized that BD responsiveness was better assessed using a statistical approach, linked to each individual's spirometric measurements, rather than the variability of others. We retrospectively analyzed 1-year's pre- and post-BD spirometric tests from our hospital's clinical laboratory. Using measurements of forced expiratory volume in 1-s (FEV(1)), forced expiratory volume in 3-s (FEV(3)), and forced vital capacity (FVC) from each of three satisfactory forced pre-BD and three satisfactory forced post-BD spirometric maneuvers, we classified each of 313 consecutive patient studies as responders or non-responders in two ways. First, we used ATS/ERS guideline criteria based on population variability. Second, we used unpaired, single-tailed t-tests at P<0.05 for FEV(1), FEV(3), and FVC, considering the variability of and difference between each individual's pre- and post-BD maneuvers. 135 studies were both ATS/ERS and t-test non-responders, three were ATS/ERS responders and t-test non-responders, 86 were ATS/ERS and t-test responders, and 89 were ATS/ERS non-responders and t-test responders. The latter 89 included many patients with either low baseline FEV(1) (< 1.50 L) who could not reach the 200 mL increase criterion or high baseline FEV(1) (> 3.00 L) who could not reach the 12% increase criterion. We believe individual t-tests may categorize patient's BD responsiveness better than ATS/ERS guideline criteria which are based on population responses and require both fixed volume and percentage changes. Its usefulness by others remains to be shown.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.