Bronchoprovocation Testing

Abstract

Variable airways obstruction, as occurs in patients with asthma, can be mimicked in the laboratory by provocation with bronchoconstrictive stimuli. Such stimuli are usually inhaled in a dose-response way, causing airway narrowing by directly acting on smooth muscle or by activation of cellular or neurogenic pathways, or a combination of these. When carefully standardized, these bronchoprovocation tests provide quantitative measures of the sensitivity, reactivity, and maximal response of the airways to various bronchoconstrictors of interest. This is generally referred to as bronchial responsiveness. There are exciting developments in the understanding of the pathogenesis and pathophysiological mechanisms determining bronchial hyperresponsiveness. These have novel 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, bronchoprovocation tests will be a vital investigation tool to be combined with morphological, cellular, and molecular techniques.

Key Words:

Airway hyperreactivity - inhalation challenge tests - histamine - methacholine - bronchial hyperresponsiveness