RT Journal Article
SR Electronic
T1 Relationship Between Spontaneous Expiratory Flow-Volume Curve Pattern and Air-Flow Obstruction in Elderly COPD Patients
JF Respiratory Care
FD American Association for Respiratory Care
SP 1643
OP 1648
DO 10.4187/respcare.02296
VO 58
IS 10
A1 Nozoe, Masafumi
A1 Mase, Kyoshi
A1 Murakami, Shigefumi
A1 Okada, Makoto
A1 Ogino, Tomoyuki
A1 Matsushita, Kazuhiro
A1 Takashima, Sachie
A1 Yamamoto, Noriyasu
A1 Fukuda, Yoshihiro
A1 Domen, Kazuhisa
YR 2013
UL http://rc.rcjournal.com/content/58/10/1643.abstract
AB BACKGROUND: Assessment of the degree of air-flow obstruction is important for determining the treatment strategy in COPD patients. However, in some elderly COPD patients, measuring FVC is impossible because of cognitive dysfunction or severe dyspnea. In such patients a simple test of airways obstruction requiring only a short run of tidal breathing would be useful. We studied whether the spontaneous expiratory flow-volume (SEFV) curve pattern reflects the degree of air-flow obstruction in elderly COPD patients. METHODS: In 34 elderly subjects (mean ± SD age 80 ± 7 y) with stable COPD (percent-of-predicted FEV1 39.0 ± 18.5%), and 12 age-matched healthy subjects, we measured FVC and recorded flow-volume curves during quiet breathing. We studied the SEFV curve patterns (concavity/convexity), spirometry results, breathing patterns, and demographics. The SEFV curve concavity/convexity prediction accuracy was examined by calculating the receiver operating characteristic curves, cutoff values, area under the curve, sensitivity, and specificity. RESULTS: Fourteen subjects with COPD had a concave SEFV curve. All the healthy subjects had convex SEFV curves. The COPD subjects who had concave SEFV curves often had very severe airway obstruction. The percent-of-predicted FEV1% (32.4%) was the most powerful SEFV curve concavity predictor (area under the curve 0.92, 95% CI 0.83–1.00), and had the highest sensitivity (0.93) and specificity (0.88). CONCLUSIONS: 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 unable to perform a satisfactory FVC maneuver.