Chest
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Randomized Controlled Trial Clinical Trial
Reduced effect of inhaled beta 2-adrenergic agonists on lung mucociliary clearance in patients with cystic fibrosis.
It has been suggested that the defective cyclic AMP-dependent Cl- secretion and the increased Na+ absorption from airway epithelia in cystic fibrosis (CF) may lead to dehydrated secretions and impaired mucociliary clearance. Beta 2-adrenergic agonists are unable to stimulate the Cl- transport in the airways in CF while being able to do so in normal airways. Thus, we questioned whether the beta 2-adrenergic agonist, terbutaline, would improve mucociliary clearance in patients with CF as it does in healthy subjects. ⋯ We conclude that 1 mg of terbutaline did not improve mucociliary clearance significantly in the patients with CF. Also, the effect of terbutaline was much less than demonstrated earlier in healthy subjects. This is consistent with earlier findings of a lack of beta-adrenergic modulation of Cl- transport in CF. Thus, no rehydration of the dry mucus in CF is expected, and a possible beta 2-agonist-induced increase in ciliary beating would have only a minor effect on overall mucociliary clearance.
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Randomized Controlled Trial Comparative Study Clinical Trial
Emergency department treatment of severe asthma. Metered-dose inhaler plus holding chamber is equivalent in effectiveness to nebulizer.
To compare the effectiveness of administration of albuterol by nebulizer or by a metered-dose inhaler having a holding chamber attachment (hereafter "inhaler") for treatment of acute asthma in an emergency department (ED). ⋯ There was no detectable difference in effectiveness of albuterol administered by nebulizer or the inhaler system for treatment of acute asthma. There was no detectable difference in effectiveness of albuterol administered by nebulizer or the inhaler system for the treatment of acute asthma when the dose was titrated to clinical response. When compared with nebulizer, the metered-dose inhaler with holding chamber delivers a full dose of albuterol more quickly and at no higher cost.