OBJECTIVE: To evaluate studies comparing metered dose inhalers with holding chambers to nebulizers in the emergency department for the treatment of asthma exacerbation.

DATA SOURCE: Primary articles and systematic review provided by the Cochrane Airways Review Group of the Cochrane Library identified by MEDLINE search (1966–February 2004) and through secondary sources.

DATA SYNTHESIS: The Cochrane review included 21 randomized clinical trials conducted in hospital emergency departments comparing clinical outcomes following β2 agonist administration via a nebulizer or a metered dose inhaler with holding chamber. Although the relative risk ratio of hospital admission with metered dose inhaler and holding chamber did not differ in children or in adults compared to the nebulizer delivery, none of the individual studies reviewed were powered to detect a difference in the rate of hospital admission. Specific factors in the treatment of acute asthma such as assessment of severity, appropriate outcome selection, appropriate dose selection, and appropriate delivery systems need to be considered to critically evaluate the literature.

CONCLUSION: Although available randomized clinical trials suggest equivalency of metered dose inhaler plus holding chambers and nebulized delivery of inhaled β2 agonists, these trials are biased to show no difference in response. There is no data to support the advantage of one method over the other in mild to moderate asthmatic patients either clinically or economically.

This content is only available as a PDF.