Inhalation profiles of asthma patients inhaling a pressurized metered dose inhaler

<bold>Background:</bold> Inhaled medication is a cornerstone in treatment of asthma. The correct use of the inhaler is important to obtain an efficient deposition. Guidelines recommend an inhalation time for adults between 3 to 5 seconds with a peak inspiratory flow of 30 l/min (Laube et al., 2011). <bold>Aims and objectives:</bold> Aim of this study is to investigate the real inhalation profile by asthma patients using a pressurized metered-dose inhaler (pMDI) without spacer. <bold>Methods:</bold> Adult patients with asthma diagnosis and on daily inhalation therapy perform 3 to 5 inhalations with a pMDI connected to a spirometer to measure their inhalation profile. They are asked to inhale “deep, steady and long” as recommended on the patient leaflet. <bold>Results:</bold> In total 15 patients (5M/10F) were enrolled in this study. Mean age 53(18) years and mean FEV1 75 (17)% predicted. Mean duration of inhalation was 1.9 (0.43)s and mean peak flow 202.5 (53.7) L/min. The 15th – 50th – 85th percentile of PIF are depicted in figure 1. <fig><object-id>erj;64/suppl_68/PA2123/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig> <bold>Conclusions:</bold> Daily inhalation profiles of patients with asthma are much shorter in time and up to 8 times higher in peak flow as recommended by the guidelines. Further research is needed to investigate the impact on the deposition and methods to teach the patients the correct manner of inhaling the medication.