Document Detail


Orthopnea and tidal expiratory flow limitation in patients with stable COPD.
MedLine Citation:
PMID:  11157590     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Orthopnea is a common feature in COPD patients, although its nature is poorly understood. OBJECTIVE: To study the role of tidal expiratory flow limitation (FL) in the genesis of orthopnea in patients with stable COPD. MEASUREMENTS: Tidal FL was assessed in 117 ambulatory COPD patients in sitting and supine positions using the negative expiratory pressure method. The presence or absence of orthopnea was also noted. RESULTS AND CONCLUSIONS: In patients with stable COPD with tidal expiratory FL in seated and/or supine position, there is a high prevalence of orthopnea, which probably results in part from increased inspiratory efforts due to dynamic pulmonary hyperinflation and the concomitant increase in inspiratory threshold load due to intrinsic positive end-expiratory pressure. Increased airway resistance in supine position due to lower end-expiratory lung volume probably also plays a role in the genesis of orthopnea.
Authors:
L Eltayara; H Ghezzo; J Milic-Emili
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Chest     Volume:  119     ISSN:  0012-3692     ISO Abbreviation:  Chest     Publication Date:  2001 Jan 
Date Detail:
Created Date:  2001-02-22     Completed Date:  2001-03-22     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0231335     Medline TA:  Chest     Country:  United States    
Other Details:
Languages:  eng     Pagination:  99-104     Citation Subset:  AIM; IM    
Affiliation:
Meakins-Christie Laboratories, and Montreal Chest Institute Research Centre, McGill University, Montreal, Quebec, Canada.
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MeSH Terms
Descriptor/Qualifier:
Aged
Airway Resistance / physiology
Dyspnea / physiopathology*
Female
Humans
Lung Diseases, Obstructive / physiopathology*
Male
Middle Aged
Pulmonary Ventilation / physiology*
Supine Position / physiology
Tidal Volume / physiology*
Work of Breathing / physiology

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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