Four of these subjects received HHN first (FVC, 1.16±0.11 L) and MDI-spacer second (FVC 1.54±0.11 L), and three received MDI-spacer first (FVC, 1.25±0.23 L) and HHN second (FVC, 1.13±0.24 L). Exclusion of the two bronchitis subjects does not change the pattern. The difference between the before and after HHN is significant to the p<0.01 level, whereas the difference between the baseline HHN and baseline MDI-spacer is significant to the p<0.05 level.
Discussion
It is apparent from this study that 15 mg of metaproterenol delivered by HHN produces a greater increase in FVC and FEVj than two inhalations (1.3 mg) of metaproterenol delivered by MDI attached to a spacer device (InspirEase) in patients with acute obstructive pulmonary disease. The dosages of metaproterenol used in this comparison were the “standard” recommended dosages. Some authors have suggested that the recommended maintenance dose of MDI aerosol bronchodilator is suboptimal, especially for the patient with acute bronchospasm.
The study population for this comparison consisted of patients who had an initial aerosol bronchodilator treatment ordered by their primary physician. The subjects in this study, therefore, should be typical of patients who whould receive aerosol bronchodilator treatments in a hospital respiratory therapy setting or emergency department.