RESUMO
<p><b>OBJECTIVE</b>To evaluate the effectiveness of a helium-oxygen mixture (79%He- 21%O(2)) as an aerosolizing compressed gas for beta(2)-agonist therapy in patients with an asthma exacerbation.</p><p><b>METHODS</b>Twenty-four patients in the outpatient department with a mild to moderate exacerbation of asthma were enrolled. The patients were randomly divided into an experimental group (13 cases) and a control group (11 cases). The experimental group inhaled Berotec with heliox-driven, and the control group inhaled Berotec with compressed air-driven. Eight hospitalized patients in the respiratory department with severe exacerbation of asthma were enrolled. The patients inhaled Berotec with heliox-driven or compressed air-driven in a random order.</p><p><b>RESULTS</b>The results of spirometric parameters and arterial blood-gas analysis were measured. In the mild to moderate asthma patients, no statistical differences between the two groups for forced vital capacity (FVC), forced expired volume in one second (FEV(1)), and expiratory flow in 50% forced vital capacity (FEF(50)) were presented. But the severe patients showed significant differences between heliox-driven and compressed air-driven for FVC, FEV(1), FEF(50) and partial pressure of oxygen (PaO(2)).</p><p><b>CONCLUSIONS</b>Compared with the traditional inhalation of beta(2)-agonist therapy using compressed air-driven, the method of inhaling beta(2)-agonist with heliox-driven has more obvious benefits for those suffering from severe asthma. This is likely due to the cooperative effects between inhaling heliox on its physical gas properties and improving delivery of beta(2)-agonist in the treatment of exacerbation of severe asthma.</p>