[Relationship between respiratory reserve in the flow-volume curve and the expected ergometric capacity]

To evaluate the physical work capacity in patients with chronic obstructive lung disease (COLD) it was checked, if determination of breathing reserve can replace the exercise test with blood gas analysis. In 28 patients with lung disease and 7 healthy subjects the flow-volume-curve under resting conditions and during the forced breathing maneuver to measure the breathing reserve and the exercise test with blood gas analysis were examined. A correlation was found between both. Therefore, in patients with COLD the determination of breathing reserve is a practicable method for estimating the physical work capacity, especially in cases with absent breathing reserve. Nevertheless, for medical opinion exercise testing is necessary.