Bronchodilatation effects of a small volume spacer used with a metered-dose inhaler

In an effort to improve the delivery of drugs to the lungs, various spacer devices have been developed to attach to metered-dose inhalers (MDIs). The aim of the study was to determine whether use of a small volume tube spacer with MDI is associated with better bronchodilatation.

We assessed bronchodilatation by measuring forced expiratory volume in 1 second (FEV(1)) before and after inhalation of fenoterol 0.4 mg (2 puffs) delivered by using a MDI in four different ways: with or without a spacer alone or with a mouth rinse of 100 mL of water immediately after inhalation with or without a spacer. Results. A total of 303 patients who had a positive bronchodilator test were studied. There was no significant difference in the Delta FEV(1) (mL or %) with or without a spacer (MDI + spacer vs. MDI, mean +/- SD, 365.1 +/- 146.5 mL vs. 356.3 +/- 131.1 mL, p = 0.696; and 21.4 +/- 9.4% vs. 21.4 +/- 9.5%, p = 0.968, respectively). When patients rinsed their mouth after inhalation, bronchodilatation was significantly less in those using an MDI alone compared with MDI + spacer (302.6 +/- 116.5 mL vs. 367.6 +/- 128.3 mL, p = 0.002; and 18.0% +/- 7.9% vs. 21.7% +/- 9.5%, p = 0.013, respectively).

When patients correctly use an MDI, addition of a spacer does not significantly improve bronchodilatation. However, if the mouth is rinsed after inhalation, a spacer does yield better bronchodilatation. Our results suggest that systemic effects from bronchodilator inhalation may not be negligible.