@article {Nozoerespcare.02296, author = {Masafumi Nozoe and Kyoshi Mase and Shigefumi Murakami and Makoto Okada and Tomoyuki Ogino and Kazuhiro Matsushita and Sachie Takashima and Noriyasu Yamamoto and Yoshihiro Fukuda and Kazuhisa Domen}, title = {The relationship between spontaneous expiratory flow-volume curve configuration and airflow obstruction in elderly COPD patients}, elocation-id = {respcare.02296}, year = {2013}, doi = {10.4187/respcare.02296}, publisher = {Respiratory Care}, abstract = {Background: Assessment of the degree of airflow obstruction is important for determining the treatment strategy in chronic obstructive pulmonary disease (COPD) patients. However, in some elderly COPD patients, measurement of a forced vital capacity (FVC) to assess the degree of airflow obstruction is often impossible because of cognitive dysfunction or severe dyspnea. In such circumstances, a simple test of airways obstruction requiring only a short run of tidal breathing would be useful. This study was designed to examine whether the spontaneous expiratory flow-volume (SEFV) curve configuration reflects the degree of airflow obstruction in elderly COPD patients. Methods: Thirty-four elderly patients (mean {\textpm} SD age: 80 {\textpm} 7 y) with stable COPD (\%FEV1 39.0\%{\textpm}18.5\% predicted) underwent measurements of flow-volume curves during quiet breathing and FVC. Twelve age-matched healthy subjects were also studied. The SEFV curve configuration (concavity/convexity), spirometry, breathing pattern, and demographic characteristics were examined. The SEFV curve concavity/convexity prediction accuracy was also examined by calculating the receiver operating characteristic (ROC) curves, cut-off values, area under the curve (AUC), sensitivity, and specificity of these indices. Results: Fourteen patients showed a concave SEFV curve, and all healthy subjects showed convex curves. The patients who showed concave curves often had very severe airway obstruction. The predicted value of \%FEV1 (32.4\%) was the most powerful SEFV curve concavity predictor, with an AUC of 0.92 (95\% CI 0.83{\textendash}1.00), with the highest sensitivity and specificity (0.93, 0.88, respectively) . Conclusion: Concavity of the SEFV curve obtained during tidal breathing may be a useful test for determining the presence of very severe obstruction in elderly patients not able to perform a satisfactory FVC maneuver.}, issn = {0020-1324}, URL = {https://rc.rcjournal.com/content/early/2013/04/09/respcare.02296}, eprint = {https://rc.rcjournal.com/content/early/2013/04/09/respcare.02296.full.pdf}, journal = {Respiratory Care} }