A step test to assess exercise-related oxygen desaturation in interstitial lung disease
A 6-min step test (6MST) may constitute a practical method for routinely assessing effort tolerance and exercise-related oxyhaemoglobin desaturation (ERD) in the primary care of patients with interstitial lung disease.In total, 31 patients (19 males) with idiopathic pulmonary fibrosis I and chronic...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2007 |
| País: | Brasil |
| Institución: | Universidade Federal de São Paulo (UNIFESP) |
| Repositorio: | Repositório Institucional da UNIFESP |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.unifesp.br:11600/29480 |
| Acceso en línea: | http://dx.doi.org/10.1183/09031936.00094006 http://repositorio.unifesp.br/handle/11600/29480 |
| Access Level: | acceso abierto |
| Palabra clave: | exercise induced exercise tests interstitial lung diseases oxygen saturation oxygen uptake pulmonary dysfunction |
| Sumario: | A 6-min step test (6MST) may constitute a practical method for routinely assessing effort tolerance and exercise-related oxyhaemoglobin desaturation (ERD) in the primary care of patients with interstitial lung disease.In total, 31 patients (19 males) with idiopathic pulmonary fibrosis I and chronic hypersensitivity pneumonia were submitted, on different days, to two 6MSTs. Physiological responses were compared with those found on maximal and submaximal cycle ergometer tests at the same oxygen uptake I Chronic breathlessness was also determined, as measured by the baseline dyspnoea index (BDI).Responses to 6MST were highly reproducible: 1.3 +/- 2.0 steps(.)min(-1), +/- 5 beats(.)min(-1) (cardiac frequency), +/- 50 mL(.)min(-1) (V'O-2), +/- 7 L(.)min(-1) (minute ventilation) and +/- 2% (arterial oxygen saturation measured by pulse oximetry (Sp,O-2)). the number of steps climbed in 6 min was correlated to peak V'O-2 and the BDI. There were significant associations among the tests in relation to presence (change in Sp,O-2 between rest and exercise >= 4%) and severity (Sp,O-2 < 88%) of ERD. Four patients, however, presented ERD only in response to 6MST. Resting diffusing capacity of the lung for carbon monoxide and alveolar-arterial oxygen tension difference were the independent predictors of the number of steps climbed.A single-stage, self-paced 6-min step test provided reliable and reproducible estimates of exercise capacity and exercise-related oxyhaemoglobin desaturation in interstitial lung disease patients. |
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