The combined measurement of the pulmonary diffusing capacity to carbon monoxide (CO) and nitric oxide (NO) (DLCO/NO) has recently been standardised and validated for clinical use. It is thus ideal for assessing acute changes in pulmonary diffusing capacity and its components during various physiological manoeuvres. These changes are thought to involve acute changes in pulmonary perfusion and are notably relevant for patients with chronic obstructive pulmonary disease (COPD), in which they may be related to exertional dyspnoea. The aim of the present study is to investigate the effects of acute exercise on pulmonary diffusing capacity, and to determine the day-to-day repeatability of such assessments.
