Liu N, et al. - Among patients recovering from an acute exacerbation of chronic obstructive pulmonary disease (AECOPD), researchers determined silent aspiration by using radionuclide imaging. They also assessed the influences of exercise-induced dyspnoea on silent aspiration in patients having COPD. This study also included healthy volunteers of similar age. They randomized aspiration-negative AECOPD patients into two subgroups. Symptom-limited incremental cycle exercise test was performed by group A patients. They asked patients in group B to rest on the exercise bicycles. Group C, including aspiration-negative healthy volunteers, were aked to undergo symptom-limited incremental cycle exercise test. At 30 min post-exercise, a radionuclide aspiration test was performed by all groups. Compared with healthy volunteers of similar age, significantly higher silent aspiration rates were observed in recovering AECOPD patients. The evidence generated in this study lacked sufficient strength to support the patients with exercise-induced dyspnoea increased aspiration rate.