Nebulizers: principles and performance.

Nebulizers have been used clinically for many years. Despite the increasing use of metered-dose inhalers and dry powder inhalers, it is likely that nebulizers will continue to be used in selected patients. A number of factors affect nebulizer performance, and these should be appreciated by clinicians who use these devices. Several new designs have recently become available that improve the performance of the nebulizer, but their cost-effectiveness remains to be determined.