TY - JOUR T1 - The relationship between spontaneous expiratory flow-volume curve configuration and airflow obstruction in elderly COPD patients JF - Respiratory Care DO - 10.4187/respcare.02296 SP - respcare.02296 AU - Masafumi Nozoe AU - Kyoshi Mase AU - Shigefumi Murakami AU - Makoto Okada AU - Tomoyuki Ogino AU - Kazuhiro Matsushita AU - Sachie Takashima AU - Noriyasu Yamamoto AU - Yoshihiro Fukuda AU - Kazuhisa Domen Y1 - 2013/04/09 UR - http://rc.rcjournal.com/content/early/2013/04/09/respcare.02296.abstract N2 - 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 ± SD age: 80 ± 7 y) with stable COPD (%FEV1 39.0%±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 0.83–1.00), 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. ER -