Current treatment guidelines for patients with acute asthma include the use of an inhaled, short-acting beta2 agonist. This medication may be administered by intermittent or continuous nebulization or by metered-dose inhalers (MDIs). The preferred method of administration in emergency departments has been nebulizers. Nebulizers have been shown to deliver more medication than MDIs with spacers, but apparently with no added clinical benefit. In addition, the use of nebulizers is associated with a higher incidence of medication side effects, such as anxiety and tremor. Nebulizers are more expensive than MDIs. Small studies have reviewed the benefit of nebulizers versus MDIs with spacers in administering a short-acting beta2 agonist. Newman and associates studied the effectiveness of these two delivery systems in the treatment of acute asthma exacerbations.
The study was a prospective, open-label trial in a large urban emergency department. All patients seen in the emergency department for acute exacerbation of asthma over a period of two and one-half years were enrolled in the study. During the first 12 months of the study, emergency department personnel used a standard treatment protocol that included albuterol administered by a nebulizer. During the final 18 months of the study, the albuterol was administered by an MDI with a spacer, and patients were given education about managing their asthma using a peak-flow meter, using an MDI with a spacer, and using inhaled corticosteroids. Measurements included pulmonary function tests, clinical outcomes, and laboratory and financial data.
There was no difference between the two treatment groups with regard to hospital admission rates. Use of the MDI with spacer provided greater improvement in peak-flow rates than use of the nebulizer. In addition, the MDI-with-spacer group spent less time in the emergency department, had a lower total albuterol dose, and showed greater improvement in arterial blood gases. The relapse rates at days 14 and 21 were significantly lower for the MDI-with-spacer treatment group than for those who were treated by nebulizer.
The authors conclude that albuterol administered by an MDI with a spacer is an efficient and cost-effective method of treating adult patients with acute exacerbation of asthma. Therefore, the use of an MDI with a spacer to deliver albuterol in the emergency room is an important alternative to the use of nebulizers in asthmatic patients with acute flare-ups.