[Ergospirometry in sarcoidosis patients].

Our investigation should clarify the question of whether cardiopulmonary exercise testing (CPX) offers additional information of clinical relevance in patients with pulmonary sarcoidosis. We investigated the relationship between changes of lung function including the diffusing capacity and the changes of gas exchange. Furthermore, we determined the correlation of functional and morphological lung changes on the basis of radiological parameters and on the influence of a steroid therapy over the gas exchange. Forty-seven patients with histologically diagnosed pulmonary sarcoidosis were examined. The lung function test includes the measurement of lung volumes with spirometry and the diffusing capacity of carbon monoxide in the single breath technique. Minute ventilation, oxygen uptake at maximum, oxygen pulse, functional dead space/tidal volume ratio, anaerobic threshold, and alveolar-arterial oxygen difference were measured continuously during exercise. We found significant correlations between the lung volumes and the CPX data. An increased relative minute ventilation and an increased alveolar-arterial oxygen difference with exercise allows a more objective differentiation in radiological stages I and II than does the lung function at rest. A steroid therapy improves the effectivity of alveolar ventilation and an improvement of the ventilation-perfusion-match. The CPX detects early changes of pathological gas-exchange, before the lung function at rest is evident pathologically. It offers additional information on the pathophysiology of sarcoidosis, and is useful in reviewing steroid therapy.