In patients with asthma, FEVj and dyspnea score improved significantly at 30 and 90 minutes after the start of treatment in both treatment groups. In the patients with COPD, the dyspnea score improved significantly at 30 and 90 minutes in both treatment groups, but the FEV! improved significantly at 30 minutes only after the HHN. Ninety minutes after the start of treatment, the FE Vi was significantly improved in both treatment groups of patients with COPD.
Another placebo-controlled parallel study of patients with acute exacerbation of bronchial asthma also demonstrated the equivalence of HHN and three inhalations of MDI-metaproterenol delivered by a portable spacer device with a unidirectional flow valve (MDI-Aerochamber). Significant improvement in FVC and FEV, was noted after treatment in both treatment groups (HHN and MDI-Aerochamber). Even though the studies by Turner et al and Salzman et al failed to demonstrate a difference between three inhalations of metaproterenol via MDI-spacer and 15 mg of metaproterenol via HHN, both studies showed a significant increase in FEVi after the MDI-spacer. Our study, which used only two inhalations of MDI-spacer, failed to demonstrate a significant improvement in spirometry.