Article

Patterns of dynamic hyperinflation during exercise and recovery in patients with severe chronic obstructive pulmonary disease.

National and Kapodistrian University of Athens Medical School, Thorax Foundation, Centre for Applied Biomedical Research and Education, 10675 Athens, Greece.
Thorax (impact factor: 6.84). 10/2005; 60(9):723-9. DOI:10.1136/thx.2004.039115 pp.723-9
Source: PubMed

ABSTRACT Not all patients with severe chronic obstructive pulmonary disease (COPD) progressively hyperinflate during symptom limited exercise. The pattern of change in chest wall volumes (Vcw) was investigated in patients with severe COPD who progressively hyperinflate during exercise and those who do not.
Twenty patients with forced expiratory volume in 1 second (FEV(1)) 35 (2)% predicted were studied during a ramp incremental cycling test to the limit of tolerance (Wpeak). Changes in Vcw at the end of expiration (EEVcw), end of inspiration (EIVcw), and at total lung capacity (TLCVcw) were computed by optoelectronic plethysmography (OEP) during exercise and recovery.
Two significantly different patterns of change in EEVcw were observed during exercise. Twelve patients had a progressive significant increase in EEVcw during exercise (early hyperinflators, EH) amounting to 750 (90) ml at Wpeak. In contrast, in all eight remaining patients EEVcw remained unchanged up to 66% Wpeak but increased significantly by 210 (80) ml at Wpeak (late hyperinflators, LH). Although at the limit of tolerance the increase in EEVcw was significantly greater in EH, both groups reached similar Wpeak and breathed with a tidal EIVcw that closely approached TLCVcw (EIVcw/TLCVcw 93 (1)% and 93 (3)%, respectively). EEVcw was increased by 254 (130) ml above baseline 3 minutes after exercise only in EH.
Patients with severe COPD exhibit two patterns during exercise: early and late hyperinflation. In those who hyperinflate early, it may take several minutes before the hyperinflation is fully reversed after termination of exercise.

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Keywords

approached TLCVcw
 
baseline 3 minutes
 
chest wall volumes
 
EEVcw
 
EIVcw
 
EIVcw/TLCVcw 93
 
expiratory volume
 
optoelectronic plethysmography
 
patients EEVcw
 
progressive significant increase
 
ramp incremental cycling test
 
severe chronic obstructive pulmonary disease
 
severe COPD
 
severe COPD exhibit
 
similar Wpeak
 
symptom limited exercise
 
termination
 
tidal EIVcw
 
TLCVcw
 
total lung capacity