Box-wisker plots of the percentage changes of VA per litre of expired volume (Delta VA/VE) in healthy individuals and in COPD patients

Abstract

<p><b>Copyright information:</b></p><p>Taken from "Assessment of the alveolar volume when sampling exhaled gas at different expired volumes in the single breath diffusion test"</p><p>http://www.biomedcentral.com/1471-2466/7/18</p><p>BMC Pulmonary Medicine 2007;7():18-18.</p><p>Published online 19 Dec 2007</p><p>PMCID:PMC2235885.</p><p></p> The horizontal lines represent the 50th percentile (median); limits of boxes are the 25th and 75th percentiles; the wiskers are the 10th and 90th percentiles. More than 90% of patients with COPD showed significant changes in alveolar volume when sampled at different intervals of lung volume. This suggests a different time constant of lung units coupled with a non-homogeneous distribution of ventilation