Bronchodilatation Effects of a Small Volume Spacer Used With a Metered-Dose Inhaler

Administration of bronchodilator drugs with metered-dose inhalers (MDIs) is difficult for some patients because the timing of the spray and the inhalation must be coordinated exactly. Use of spacers seems to improve delivery in these patients. It is not clear, however, if there is any advantage to a spacer for patients who are able to use an MDI with correct technique.

The purpose of the present study is to determine whether use of a small volume spacer is associated with better bronchodilatation in an unselected population of patients with documented reversible airflow limitations. The intervention in the first part of the study is use of an MDI with or without a spacer to deliver a bronchodilator (2 puffs, 0.4 mg of fenoterol). Spirometry is performed before and after the inhalation.

The second part of the study is conducted identically to the first with the same conditions and variables but with the addition of rinsing the mouth with 100 mL of water after inhaling the bronchodilator but before the second spirometry measurement.

The outcome to be measured is the increase in forced expiratory volume in 1 second (FEV1) and forced expiratory flow rate (FEF25-75%).

Inclusion criteria

• age > 6 years old,
• subjects known to have reversible airway limitation with demonstrated response to bronchodilators on spirometry.

Exclusion criteria

• refusal to participate,
• negative bronchodilator test,
• poor performance of pulmonary function testing.