Effects of cpap on the physical exercise tolerance of moderate to severe chronic obstructive pulmonary disease

Objective: The aim of this study was to evaluate the effect of continuous positive airway pressure (CPAP) on the exercise tolerance of patients with moderate to severe chronic obstructive pulmonary disease (COPD). Methods: ten men with COPD (69 ± 9 years), FEV 1 /FVC (58.90 ± 11.86%) and FEV 1 (40.98 ± 10.97% of predict) were submitted to a symptom-limited incremental exercise test (IT) on the cyclo ergometer. Later, on another visit, they were randomized to perform a constant load exercise protocol until maximal tolerance with and without CPAP (5 cm H 2 O) in the following conditions: i) 50% of the peak workload; and ii) 75% of the peak workload. Heart rate (HR), arterial pressure (AP) and peripheral oxygen saturation were obtained at rest and during the exercise protocols. For statistical procedures, Shapiro-Wilk normality test and two-way ANOVA with Tukey post hoc (p<0.05) were performed. Results: There was a significant improvement in exercise time tolerance during the 75% of the peak workload protocol with CPAP when compared with spontaneous breath (SB) (438±75 vs. 344±73ms, respectively). Conclusion: CPAP with 5 cm H 2 O seems to be useful to improve exercise tolerance in patients with COPD.