Document Detail

Improvement in exercise endurance in patients with chronic airflow limitation using continuous positive airway pressure.
MedLine Citation:
PMID:  3059897     Owner:  NLM     Status:  MEDLINE    
To cope with the increased ventilatory demands of exercise, patients with severe expiratory flow limitation adopt strategies that ultimately place greater demands on their inspiratory muscles. Increased inspiratory muscle work may contribute to dyspnea causation and exercise limitation in such patients even before their ventilatory ceiling is attained. In this setting, continuous positive airway pressure (CPAP) should, by favorably affecting inspiratory muscle function and respiratory sensation, improve exercise performance. Six patients with chronic airflow limitation (CAL) (FEV1 +/- SD = 35 +/- 12% predicted) undertook constant-load, submaximal, cycle exercise at 50% of their predetermined maximal oxygen consumption: CPAP of 4 to 5 cm H2O was delivered during one exercise session and bracketed by one or two unassisted control sessions. In four patients, CPAP-assisted (4 to 5 cm H2O) exercise was bracketed by two unassisted control exercise sessions; two remaining patients undertook CPAP-assisted exercise and one unassisted control session. CPAP resulted in a significant increase in exercise endurance time (TLIM) (by 48%: CPAP TLIM (mean +/- SE) = 8.82 +/- 1.90 min; averaged control TLIM = 5.98 +/- 1.23 min (p less than 0.01). CPAP effectively ameliorated exertional dyspnea in the majority of patients; selected dyspnea ratings (Borg scale) during control (final minute) and CPAP at isotime, at comparable levels of ventilation, were (mean +/- SD) 7.83 +/- 2.25 and 5.5 +/- 2.2, respectively (p less than 0.025). Breathing frequency fell significantly during CPAP application (at isotime) by 17% (p less than 0.02); other steady-state ventilatory variables and end-expiratory lung volumes were not significantly different during CPAP and control.(ABSTRACT TRUNCATED AT 250 WORDS)
D E O'Donnell; R Sanii; M Younes
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The American review of respiratory disease     Volume:  138     ISSN:  0003-0805     ISO Abbreviation:  Am. Rev. Respir. Dis.     Publication Date:  1988 Dec 
Date Detail:
Created Date:  1989-01-24     Completed Date:  1989-01-24     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0370523     Medline TA:  Am Rev Respir Dis     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1510-4     Citation Subset:  AIM; IM    
Respiratory Investigation Unit, University of Manitoba, Winnipeg, Canada.
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MeSH Terms
Inspiratory Capacity
Lung Diseases, Obstructive / physiopathology,  therapy*
Middle Aged
Physical Endurance*
Positive-Pressure Respiration*
Pulmonary Ventilation
Reference Values
Tidal Volume

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

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