[The value of the quantitative acetylcholine-test for the estimate of the bronchial reactivity (author's transl)].

By the quantitative acetylcholine-test, described in details, the threshold amount of acetylcholine is determined, which after inhalation is able to provoke bronchial obstruction just measureable. By double-determinations nearly identical results are obtained. Errors may result from the patient's non-cooperation, especially in young children and from unexact dosage of acetylcholine by the nebulizer. There exists a circadian periodicity of bronchial reactivity having its climax in the night an the early morning. Therefore the test should be performed always at the same hour in the morning.