[The inhalation 1 concentration test for the assessment of bronchial reactivity]

An unspecific bronchial provocation challenge with a 1-concentration test is a reliable method to distinguish between normal and hyperreactive persons. The patient inhales a bronchoconstricting substance such as methacholine. A significant change of lung function, for example an increase of airway resistance, characterizes a hyperreactive bronchial system. The continuous registration of transcutaneous oxygen pressure is helpful concerning a strong reaction or a peripheral airway obstruction. An exaggerated increase of airway resistance after provocation test can be treated rapidly by inhalation of sympathicomimetics. No complications were registered. Comparative studies showed a good reproducibility of this method. Summarizing, the 1-concentration test is simple, easy to perform and suitable especially for investigations in occupational medicine or epidemiology.