Comparison of a Hand-held Nebulizer with a Metered Dose Inhaler-Spacer Combination in Acute Obstructive Pulmonary Disease (10)

There was no change in pulse, respiratory rate, or blood pressure in the combined groups or in any of the subgroups after either HHN or MDI-spacer. Subjectively, study participants found both methods of metaproterenol delivery beneficial. Four subjects expressed a preference for HHN and four expressed a preference for MDI-spacer, and the remaining nine subjects did not have a definite preference.
Because of the crossover design of the study, a separate analysis was made of the order of treatment, that is which subjects received HHN first and which received MDI-spacer first, and whether there was any carryover effect of the first treatment on the baseline spirometry prior to the second aerosol treatment. The interval between treatments for all subjects was 2.96 ±0.27 hours (range, 1.25 to 5.0 hours), and was not different for subjects who received therapy via MDI-spacer first or HHN first. There was no difference in baseline spirometry based on the order of treatment, that is, between patients who received M Di-spacer first and those given nebulizer first. There was no significant difference in baseline spirometry prior to administration of MDI-spacer or HHN except for the FVC in the COPD subgroup (Table 1).