Um programa de treinamento de endurance influencia o movimento toracoabdominal de pacientes com Doença Pulmonar Obstrutiva Crônica?

Abstract

The presence of asynchronous thoracoabdominal motion (TAM) at rest and particularly during exercise is considered an important sign of chronic obstructive pulmonary disease (COPD), and has been associated with higher severity of the disease. Although the mechanisms that determine asynchrony have not been elucidated this have been related to respiratory muscles dysfunction, determined by hyperinflation. Lower-limb endurance training provides important positive effects, however, studies addressing its influence on asynchrony of patients with COPD have not been found. The aim of this study was to analyze the impact of lower-limb endurance training in TAM during exercise in COPD patients as well as to compare TAM at rest and during exercise. It was conducted a single-subject experimental design with periodic assessments, during maximal incremental tests, with two phases: A-baseline, without any intervention for 6 weeks; B-lower-limb endurance training for 12 weeks (three times/week). Two participants with severe COPD, according to GOLD, were studied. Respiratory inductive plethysmography was used for assessing: Inspiratory Phase Relation (PhRIB), Expiratory Phase Relation (PhREB) and Cross-Correlation Function (CCF). Cuts of plethysmography waveforms were donne at rest and two levels of exercise (same load and peak load). For comparisons of TAM between baseline and training phases in two levels of exercise were considered response to intervention results with concordance between Visual Analysis and at least one statistical test (Two Standard Deviation Band test and Celeration Line), considering significant p<0.05. Comparisons of TAM between rest and two levels of exercise were performed with ANOVA for repeated measures, considering significant p<0.017 according to Bonferroni correction. Comparisons of TAM between baseline and intervention phases showed significant decrease in PhRIB during same load and in PhREB during peak load in Participant 1, as well significant decrease in PhRIB and PhREB during same load and in PhRIB during peak load in Participant 2. No significant change was observed in other variables. Comparisons of TAM between rest and exercise showed significant increase in PhRIB, PhREB and CCF during exercise, in both participants, without significant differences between two levels of exercise. It was also observed that waveform during exercise was nonsinusoidal and irregularities appear to be arising out of abdominal compartment. These results suggest that exercise and endurance training influenced TAM of patients with COPD. Lower-limb endurance training promoted positive effect, decreasing asynchrony during exercise; however, the behavior of TAM variables throughout the study was not the same for both participants evaluated. This different behavior may be caused by individual characteristics, which highlights the possibility of distinct dynamic hyperinflation patterns. Exercise increased asynchrony relate to rest. Irregularities from abdominal compartment seem to be crucial for asynchrony observed during exercise.