Can ventilation-feedback training augment exercise tolerance in patients with chronic obstructive pulmonary disease?
BACKGROUND
Exercise-induced dynamic hyperinflation contributes to decreased exercise tolerance in chronic obstructive pulmonary disease (COPD). It is unknown whether respiratory retraining (ventilation-feedback [VF] training) can affect exercise-induced dynamic hyperinflation and increase exercise tolerance.


OBJECTIVE
To determine whether patients with COPD would achieve longer exercise duration if randomized to a combination of exercise training plus VF training than either form of training on its own.


METHODS
A total of 64 patients randomized to 1 of 3 groups: VF plus exercise (n = 22), exercise alone (n = 20), and VF alone (n = 22).


RESULTS
Exercise duration before and after 36 training sessions and exercise-induced dynamic hyperinflation and respiratory pattern before and after training were measured. In the 49 patients who completed training, duration of constant work-rate exercise was 40.0 (+/- 20.4) minutes (mean +/- SD) with VF plus exercise, 31.5 (+/- 17.3) minutes with exercise alone, and 16.1 (+/- 19.3) minutes with VF alone. Exercise duration was longer in VF plus exercise than in VF alone (P < 0.0001), but did not reach predetermined statistical significance when VF plus exercise was compared with exercise alone (P = 0.022) (because of multiple comparisons, P </= 0.0167 was used for statistical significance). After training, exercise-induced dynamic hyperinflation, measured at isotime, in VF plus exercise was less than in exercise alone (P = 0.014 for between-group changes) and less than in VF alone (P = 0.019 for between-group changes). After training, expiratory time was longer in VF plus exercise training (P < 0.001), and it was not significantly changed in the other two groups.


CONCLUSIONS
The combination of VF plus exercise training decreases exercise-induced dynamic hyperinflation and increases exercise duration more than VF alone. An additive effect to exercise training from VF was not demonstrated by predetermined statistical criteria.
Collins
Eileen G
EG
Research and Development (151), Edward Hines, Jr. VA Hospital, Hines, IL 60141, USA. ecollins@uic.edu
Langbein
W Edwin
WE
Fehr
Linda
L
O'Connell
Susan
S
Jelinek
Christine
C
Hagarty
Eileen
E
Edwards
Lonnie
L
Reda
Domenic
D
Tobin
Martin J
MJ
Laghi
Franco
F
D000368:Aged; D001642:Bicycling; D001676:Biofeedback, Psychology / Q000379:methods*; D001945:Breathing Exercises; D005080:Exercise Test; D005081:Exercise Therapy / Q000379:methods*; D017079:Exercise Tolerance / Q000502:physiology*; D006787:Hospitals, Veterans; D006801:Humans; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000534:rehabilitation*; D012138:Respiratory Therapy / Q000379:methods*; D016138:Walking