Purpose of review
To review bronchial provocations tests used in the measurement of bronchial hyperresponsiveness to help in the diagnosis of asthma.
Recent findings
The bronchial provocations tests reviewed include
exercise,
methacholine, AMP and
mannitol, with reference to methodology and monitoring of treatment.
Summary
Methacholine is used for identifying bronchial hyperresponsiveness and to guide treatment.
Exercise is used as a bronchial provocation test because demonstrating prevention of
exercise-induced asthma is an indication for use of a drug. Both of these tests are being used to study tolerance to β
2 agonists. There is increasing use of eucapnic voluntary hyperpnea as a surrogate bronchial provocation test for
exercise to identify
exercise-induced asthma, particularly in athletes. For
methacholine and AMP there is concern about the different breathing patterns used to inhale these aerosols and the impact they have on the cutoff point for identifying bronchial hyperresponsiveness. A new test that uses a kit containing prepacked capsules of different doses of
mannitol and a delivery device is discussed. There is increasing interest in using tests that act indirectly by release of mediators because the bronchial hyperresponsiveness itself is an indicator of the presence of inflammation. Since treatment of inflammation leads to loss of bronchial hyperresponsiveness to indirect stimuli, these tests are well suited to identify success of treatment.
