Normal Routine Spirometry Can Mask COPD/Emphysema in Symptomatic Smokers.

Autor: Gelb AF; Pulmonary Division, Department of Medicine, Lakewood Regional Medical Center, Lakewood, California, United States and David Geffen School of Medicine at University of California-Los Angeles Health Sciences, Los Angeles, California, United States., Yamamoto A; Department of Pathology, Lakewood Regional Medical Center, Lakewood, California, United States., Verbeken EK; Department of Pathology, Katholieke Univeritair Ziekenhuis Gasthuisberg, Leuven, Belgium., Hogg JC; University of British Columbia James Hogg Research Centre, St. Paul`s Hospital Vancouver, British Columbia, Canada., Tashkin DP; Division of Pulmonary and Critical Care Medicine, David Geffen School of Medicine at University of California-Los Angeles Health Sciences, Los Angeles, California, United States., Tran DNT; Independent pulmonary function investigator, Lakewood, California, United States., Moridzadeh RM; Independent pulmonary function investigator, Lakewood, California, United States., Fraser C; Independent pulmonary function investigator, Lakewood, California, United States., Schein MJ; Department of Radiology, Lakewood Regional Medical Center, Lakewood, California, United States., Decramer M; Department of Clinical and Experimental Medicine, Katholieke Univeritair Leuven-University of Leuven and University Hospitals Leuven, Leuven, Belgium., Glassy EF; Affiliated Pathologists Medical Group, Rancho Dominguez, California, United States., Nadel JA; Cardiovascular Research Institute and Departments of Medicine, Physiology, and Radiology, School of Medicine, University of California San Francisco, San Francisco, California, United States.
Jazyk: angličtina
Zdroj: Chronic obstructive pulmonary diseases (Miami, Fla.) [Chronic Obstr Pulm Dis] 2021 Jan; Vol. 8 (1).
DOI: 10.15326/jcopdf.2020.0176
Abstrakt: Background: Recent studies have emphasized the difficulty of early detection of chronic obstructive pulmonary disease (COPD) in symptomatic smokers with normal routine spirometry. This includes post-bronchodilator normal forced expiratory volume in 1 second (FEV 1 )(L)≥80% predicted, forced vital capacity (FVC)(L)≥80% predicted, and FEV 1 /FVC ≥70% or greater than age corrected lower limit of normal (LLN). However, in COPD the pathologic site of small airway obstruction and emphysema begins in the small peripheral airways ≤2 mm id which normally contribute <20% of total airway resistance.
Methods: Expiratory airflow at high and low lung volumes post-bronchodilator were measured and correlated with lung computed tomography (CT) and lung pathology (6 patients) in 16 symptomatic, treated smokers, and all with normal routine spirometry.
Results: Despite normal routine spirometry, all16 patients had isolated, abnormal forced expiratory flow at 75% of FVC (FEF 75 ) using data from Knudson et al, Hankinson et al NHAMES III, and Quanjer et al and the Global Lung Function Initiative. This reflects isolated detection of small airways obstruction and/or emphysema. Measuring airflow at FEF 50 detected only 8 of 16 patients, maximal expiratory flow at 25%-75% of FVC (MEF 25-75 ) only 4 of 16, residual volume (RV) 4 of 16, and RV to total lung capacity ratio only 2 of 16. There was excellent correlation between limited lung pathology and lung CT for absence of emphysema.
Conclusion: This study confirms our earlier observations that detection of small airways obstruction and/or emphysema, in symptomatic smokers with normal routine spirometry, requires analysis of expiratory airflow at low lung volumes, including FEF 75 . Dependence upon normal routine spirometry may result in clinical and physiologic delay in the diagnosis and treatment in symptomatic smokers with emphysema and small airways obstruction.
(JCOPDF © 2021.)
Databáze: MEDLINE
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