Expiratory Flow Limitation and Its Relation to Dyspnea and Lung Hyperinflation in Patients with Chronic Obstructive Pulmonary Disease: Analysis Using the Forced Expiratory Flow-Volume Curve and Critique  

作　　者：Billy Peng Matthew Miller Mark Slootsky Ravi Patel Ahmet Baydur Billy Peng;Matthew Miller;Mark Slootsky;Ravi Patel;Ahmet Baydur(Division of Pulmonary, Critical Care, and Sleep Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA;Los Angeles County + University of Southern California Medical Center, Los Angeles, CA, USA)

机构地区：[1]Division of Pulmonary, Critical Care, and Sleep Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA [2]Los Angeles County + University of Southern California Medical Center, Los Angeles, CA, USA

出　　处：《Open Journal of Respiratory Diseases》2021年第3期91-104,共14页呼吸病期刊（英文）

摘　　要：<b>Background:</span></b><span style="font-family:""><span style="font-family:Verdana;"> Tidal expiratory flow limitation (tEFL) is defined as absence of increase in air flow during forced expiration compared to tidal breathing and is related to dyspnea at rest and minimal exertion in patients with chronic airflow limitation (CAL). Tidal EFL has not been expressed as a continuous variable (0% - 100%) in previous analyses. </span><b><span style="font-family:Verdana;">Objective:</span></b><span style="font-family:Verdana;"> To relate the magnitude of tEFL to spirometric values and Modified Medical Research Council (MMRC) score and Asthma Control Test (ACT). </span><b><span style="font-family:Verdana;">Methods:</span></b><span style="font-family:Verdana;"> Tidal EFL was computed as percent of the tidal volume (0% - 100%) spanned (intersected) by the forced expiratory-volume curve. </span><b><span style="font-family:Verdana;">Results: </span></b><span style="font-family:Verdana;">Of 353 patients screened, 192 (114 M, 78 F) patients (136 with COPD, 56 with asthma) had CAL. Overall characteristics: (mean ± SD) age 59 ± 11 years, BMI 28 ± 7, FVC (% pred) 85 ± 20, FEV1 (% pred) 66 ± 21, FEV1/FVC 55% ± 10%, RV (% pred) 147 ± 42. Tidal EFL in patients with tEFL was 53% ± 39%. Using univariate analysis, strongest correlations were between tEFL and FVC and between tEFL and RV in patients with BMI < 30 kg/m</span>^{<span style="font-family:Verdana;">2</span>}<span style="font-family:Verdana;">. In patients with nonreversible CAL, tEFL was positively associated with increasing MMRC, negatively with spirometric measurements, and positively with RV/TLC. In asthmatics, ACT scores were higher in patients with mean BMI ≥ 28 kg/m</span>^{<span style="font-family:Verdana;">2</span>}<span style="font-family:Verdana;"> (p < 0.00014) and RV/TLC values > 40% (p < 0.03). </span><b><span style="font-family:Verdana;">Conclusions:</span></b><span style="font-family:Verdana;"> Dyspnea is strongly associated with tEFL<b>Background:</span></b><span style="font-family:""><span style="font-family:Verdana;"> Tidal expiratory flow limitation (tEFL) is defined as absence of increase in air flow during forced expiration compared to tidal breathing and is related to dyspnea at rest and minimal exertion in patients with chronic airflow limitation (CAL). Tidal EFL has not been expressed as a continuous variable (0% - 100%) in previous analyses. </span><b><span style="font-family:Verdana;">Objective:</span></b><span style="font-family:Verdana;"> To relate the magnitude of tEFL to spirometric values and Modified Medical Research Council (MMRC) score and Asthma Control Test (ACT). </span><b><span style="font-family:Verdana;">Methods:</span></b><span style="font-family:Verdana;"> Tidal EFL was computed as percent of the tidal volume (0% - 100%) spanned (intersected) by the forced expiratory-volume curve. </span><b><span style="font-family:Verdana;">Results: </span></b><span style="font-family:Verdana;">Of 353 patients screened, 192 (114 M, 78 F) patients (136 with COPD, 56 with asthma) had CAL. Overall characteristics: (mean ± SD) age 59 ± 11 years, BMI 28 ± 7, FVC (% pred) 85 ± 20, FEV1 (% pred) 66 ± 21, FEV1/FVC 55% ± 10%, RV (% pred) 147 ± 42. Tidal EFL in patients with tEFL was 53% ± 39%. Using univariate analysis, strongest correlations were between tEFL and FVC and between tEFL and RV in patients with BMI < 30 kg/m</span>^{<span style="font-family:Verdana;">2</span>}<span style="font-family:Verdana;">. In patients with nonreversible CAL, tEFL was positively associated with increasing MMRC, negatively with spirometric measurements, and positively with RV/TLC. In asthmatics, ACT scores were higher in patients with mean BMI ≥ 28 kg/m</span>^{<span style="font-family:Verdana;">2</span>}<span style="font-family:Verdana;"> (p < 0.00014) and RV/TLC values > 40% (p < 0.03). </span><b><span style="font-family:Verdana;">Conclusions:</span></b><span style="font-family:Verdana;"> Dyspnea is strongly associated with tEFL

关 键 词：Air Trapping Asthma Chronic Obstructive Pulmonary Disease DYSPNEA Forced Expiratory Flow-Volume Curve HYPERINFLATION Tidal Expiratory Flow Limitation 

分 类 号：R56[医药卫生—呼吸系统]