The purpose of this study was to assess whether expiratory flow limitation (FL), as measured by applying negative pressure at the mouth during tidal expiration, is a better predictor of dyspnea than routine spirometry measurements. The study population consisted of 117 ambulatory patients with COPD. Dyspnea was assessed according to the ATS-DLD respiratory Questionnaire. Expiratory flow limitation was measured in supine and sitting positions, and expressed as a percentage of the expired control tidal volume affected by flow limitation (FL, % VT). Using Spearman's rank correlation (rs), we found that the correlation of dyspnea scale with FL was stronger (rs > 0.5) than with FVC (rs < -0.3) or FEV1 (rs < -0.4) in both positions. In a multiple regression analysis FL remained the best predictor of dyspnea scale even after adjustment for FEV1 (% pred). Finally, FL was almost as sensitive as FEV1 (% pred) but much more specific in assessing the severity of dyspnea scale. These findings sugge...
Relationship between Chronic Dyspnea and Expiratory Flow-Limitation in COPD Patients
VOLTA, Carlo Alberto;
1996
Abstract
The purpose of this study was to assess whether expiratory flow limitation (FL), as measured by applying negative pressure at the mouth during tidal expiration, is a better predictor of dyspnea than routine spirometry measurements. The study population consisted of 117 ambulatory patients with COPD. Dyspnea was assessed according to the ATS-DLD respiratory Questionnaire. Expiratory flow limitation was measured in supine and sitting positions, and expressed as a percentage of the expired control tidal volume affected by flow limitation (FL, % VT). Using Spearman's rank correlation (rs), we found that the correlation of dyspnea scale with FL was stronger (rs > 0.5) than with FVC (rs < -0.3) or FEV1 (rs < -0.4) in both positions. In a multiple regression analysis FL remained the best predictor of dyspnea scale even after adjustment for FEV1 (% pred). Finally, FL was almost as sensitive as FEV1 (% pred) but much more specific in assessing the severity of dyspnea scale. These findings sugge...I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
