The particle size of bronchodilator aerosols may be important in determining the site of deposition in the lung and their therapeutic effect. The distribution of aerosols (labelled with technetium-99m diethylene triamine pentacetic acid) of two different particle sizes has been studied by gamma camera imaging. The particles had mass median aerodynamic diameters (geometric standard deviations) o...

This paper describes a preliminary investigation into the bronchodilator action of khellin in patients with clinical bronchospasm. Khellin is one of the active principles of the plant Ammi visnaga (Linn.), which grows wild in many eastern Mediterranean countries. Simple decoctions of its seeds have apparently been used by the local native populations for generations as a spasmolytic, in particu...

Bronchodilator responsiveness (BDR) is widely considered to be a key diagnostic criterion for asthma, and is used to differentiate asthma from chronic obstructive pulmonary disease (COPD). Currently, the threshold of a 12% increase in FEV1 from baseline following inhaled salbutamol, with at least a 200 ml increase in absolute terms, is recommended as a response indicative of asthma, although re...

T he history of the bronchodilator test dates back to the late 1950s when airway diseases were classified as reversible or irreversible depending on the response to bronchodilators [1, 2]. The hope to differentiate asthma from chronic obstructive pulmonary disease (COPD) on this basis was such that the test soon gained popularity in clinical practice. Two large trials published in the mid 1980s...

In the course of doing simple lung-function tests on patients with chronic bronchitis, asthma, or emphysema it became clear that many of those using bronchodilator aerosols were not using them correctly. Since it seemed possible that such patients might not be gaining maximum benefit, and since the recently developed pressurized aerosols are expensive, it was thought reasonable to examine in mo...