Background: Acute exacerbations of asthma and chronic obstructive pulmonary disease (COPD) are associated with increased airflow Limitation, hyperinflation and respiratory muscle fatigue. It is unclear, whether patients are able to perform adequate inhalations through various inhalation devices with different orfices during an exacerbation. The aim of this study was to examine the evolution of inhalation profiles of patients inhaling through Diskus, Turbuhaler, pressurized metered dose inhaler (pMDI) and Volumatic and consequently the appropriateness of using the various devices during an exacerbation.
Measurements: 15 hospitalized patients participated in this randomized comparison of inhalation profiles through the four placebo-devices. For each device, triplicate inhalation profiles were recorded during day 1-9 of admission and in stable phase (day 50).
Results: The mean percentage of patients performing optimum inhalation profiles was 100% for Diskus, 60% for Turbuhaler, 14% for pMDI and 87% for Volumatic over the interval of day 1-9 and day 50. Patients with an inspiratory muscle strength (MIP) of less than 6kPa were generally unable to generate the optimum flow through the Turbuhaler (>60 l/min).
Conclusion: The Diskus and Volumatic can be used effectively in the acute phase of an exacerbation of asthma or COPD. The Turbuhaler could be optimally used after the fifth day of convalescence. The pMDI is rather unsuitable during an exacerbation.