BRONCHOPROVOCATION TESTING

Variable airways obstruction, as occurs in patients with asthma, can b e mimicked in the laboratory by provocation with bronchoconstrictive s timuli. Such stimuli are usually inhaled in a dose-response way, causi ng airway narrowing by directly acting on smooth muscle or by activati on of cellular or neurogenic pathways, or a combination of these. When carefully standardized, these bronchoprovocation tests provide quanti tative measures of the sensitivity, reactivity, and maximal response o f the airways to various bronchoconstrictors of interest. This is gene rally referred to as bronchial responsiveness, There are exciting deve lopments in the understanding; of the pathogenesis and pathophysiologi cal mechanisms determining bronchial hyperresponsiveness, These have n ovel clinical implications for the diagnosis and management of asthma and chronic obstructive pulmonary disease (COPD), As long as difficult breathing is considered to be the basic problem in these diseases, br onchoprovocation tests will be a vital investigation tool to be combin ed with morphological, cellular, and molecular techniques.