Adjuncts to physical training of patients with severe COPD: oxygen or noninvasive ventilation?
BACKGROUND
Previous studies have shown positive effects from noninvasive ventilation (NIV) or supplemental oxygen on exercise capacity in patients with COPD. However, the best adjunct for promoting physiologic adaptations to physical training in patients with severe COPD remains to be investigated.


METHODS
Twenty-eight patients (mean +/- SD age 68 +/- 7 y) with stable COPD (FEV(1) 34 +/- 9% of predicted) undergoing an exercise training program were randomized to either NIV (n = 14) or supplemental oxygen (n = 14) during group training to maintain peripheral oxygen saturation (S(pO2)) >/= 90%. Physical training consisted of treadmill walking (at 70% of maximal speed) 3 times a week, for 6 weeks. Patients were assessed at baseline and after 6 weeks. Assessments included physiological adaptations during incremental exercise testing (ratio of lactate concentration to walk speed, oxygen uptake [V (O2)], and dyspnea), exercise tolerance during 6-min walk test, leg fatigue, maximum inspiratory pressure, and health-related quality of life.


RESULTS
Two patients in each group dropped out due to COPD exacerbations and lack of exercise program adherence, and 24 completed the training program. Both groups improved 6-min walk distance, symptoms, and health-related quality of life. However, there were significant differences between the NIV and supplemental-oxygen groups in lactate/speed ratio (33% vs -4%), maximum inspiratory pressure (80% vs 23%), 6-min walk distance (122 m vs 47 m), and leg fatigue (25% vs 11%). In addition, changes in S(pO2)/speed, V (O2), and dyspnea were greater with NIV than with supplemental-oxygen.


CONCLUSIONS
NIV alone is better than supplemental oxygen alone in promoting beneficial physiologic adaptations to physical exercise in patients with severe COPD.
Borghi-Silva
Audrey
A
Cardiopulmonary Physiotherapy Laboratory, Physiotherapy Department, Federal University of São Carlos, São Carlos, Washington Luis, Km 235 São Carlos, São Paulo 13565-905, Brazil. audrey@ufscar.br
Mendes
Renata Gonçalves
RG
Toledo
Andreza Cristina
AC
Malosá Sampaio
Luciana Maria
LM
da Silva
Tatiane Patrocínio
TP
Kunikushita
Luciana Noemi
LN
Dutra de Souza
Hugo Celso
HC
Salvini
Tânia F
TF
Costa
Dirceu
D
D000222:Adaptation, Physiological; D000368:Aged; D005080:Exercise Test; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000502:physiology; D010102:Oxygen Inhalation Therapy / Q000379:methods*; D011175:Positive-Pressure Respiration / Q000379:methods*; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology / Q000628:therapy*; D011788:Quality of Life; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires; D016896:Treatment Outcome