Dynamic hyperinflation during treadmill exercise testing in patients with moderate to severe COPD
Objective: To characterize the presence, extent, and patterns of dynamic hyperinflation (DH) during treadmill exercise testing in patients with moderate to severe COPD. Methods: This was a cross-sectional study involving 30 non-hypoxemic patients (FEV1 = 43 +/- 14% of predicted) who were submitted t...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2012 |
| País: | Brasil |
| Institución: | Universidade Federal de São Paulo (UNIFESP) |
| Repositorio: | Repositório Institucional da UNIFESP |
| Idioma: | portugués |
| OAI Identifier: | oai:repositorio.unifesp.br:11600/44156 |
| Acceso en línea: | http://dx.doi.org/10.1590/S1806-37132012000100004 http://repositorio.unifesp.br/handle/11600/44156 |
| Access Level: | acceso abierto |
| Palabra clave: | Pulmonary disease, chronic obstructive Exercise Exercise test Inspiratory capacity |
| Sumario: | Objective: To characterize the presence, extent, and patterns of dynamic hyperinflation (DH) during treadmill exercise testing in patients with moderate to severe COPD. Methods: This was a cross-sectional study involving 30 non-hypoxemic patients (FEV1 = 43 +/- 14% of predicted) who were submitted to a cardiopulmonary exercise test on a treadmill at a constant speed (70-80% of maximum speed) to the tolerance limit (Tlim). Serial inspiratory capacity (1C) maneuvers were used in order to assess DH. Results: Of the 30 patients studied, 19 (63.3%) presented with OH (DH+ group), having greater pulmonary function impairment at rest than did those without UN (OH group). None of the variables studied correlated with exercise tolerance in the DH- group, whereas Tlim, 1C, and perception of dyspnea during exercise did so correlate in the DH+ group (p < 0.05). In the DH+ group, 7 and 12 patients, respectively, presented with a progressive and a stable pattern of DH (Delta 1C(Tlim,2min)= -0.28 +/- 0.11 L vs. 0.04 +/- 0.10 L; p <0.01). Patients with a progressive pattern of DH presented with higher perception of dyspnea/Tlim rate and lower exercise tolerance than did those with a stable pattern (354 +/- 118 s and 465 +/- 178 s, respectively; p < 0.05). Conclusions: The presence of DH is not a universal phenomenon during walking in COPD patients, even in those with moderate to severe airflow limitation. In the patients who presented DH, a progressive pattern of DH had a greater impact on exercise tolerance than did a stable pattern of DH. |
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