BACKGROUND: The characteristics of each inhalation maneuver when patients use dry powder inhalers (DPIs) are important, because they control the quality of the emitted dose. METHODS: We have measured the inhalation profiles of asthmatic children [CHILD; n=16, mean forced expiratory volume in 1 sec (FEV1) 79% predicted], asthmatic adults (ADULT; n=53, mean predicted FEV1 72%), and chronic obstructive pulmonary disease (COPD; n=29, mean predicted FEV1 42%) patients when they inhaled through an Aerolizer, Diskus, Turbuhaler, and Easyhaler using their "real-life" DPI inhalation technique. These are low-, medium-, medium/high-, and high-resistance DPIs, respectively. The inhalation flow against time was recorded to provide the peak inhalation flow (PIF; in L/min), the maximum pressure change (ΔP; in kPa), acceleration rates (ACCEL; in kPa/sec), time to maximum inhalation, the length of each inhalation (in sec), and the inhalation volume (IV; in liters) of each inhalation maneuver. RESULTS:PIF, ΔP, and ACCEL values were consistent with the order of the inhaler's resistance. For each device, the inhalation characteristics were in the order ADULT>COPD>CHILD for PIF, ΔP, and ACCEL (p<0.001). The results showed a large variability in inhalation characteristics and demonstrate the advantages of ΔP and ACCEL rather than PIFs. Overall inhaled volumes were low, and only one patient achieved an IV >4 L and ΔP >4 kPa. CONCLUSION: The large variability of these inhalation characteristics and their range highlights that if inhalation profiles were used with compendial in vitro dose emission measurements, then the results would provide useful information about the dose patients inhale during routine use. The inhalation characteristics highlight that adults with asthma have greater inspiratory capacity than patients with COPD, whereas children with asthma have the lowest. The significance of the inhaled volume to empty doses from each device requires investigation.
RCT Entities:
BACKGROUND: The characteristics of each inhalation maneuver when patients use dry powder inhalers (DPIs) are important, because they control the quality of the emitted dose. METHODS: We have measured the inhalation profiles of asthmatic children [CHILD; n=16, mean forced expiratory volume in 1 sec (FEV1) 79% predicted], asthmatic adults (ADULT; n=53, mean predicted FEV1 72%), and chronic obstructive pulmonary disease (COPD; n=29, mean predicted FEV1 42%) patients when they inhaled through an Aerolizer, Diskus, Turbuhaler, and Easyhaler using their "real-life" DPI inhalation technique. These are low-, medium-, medium/high-, and high-resistance DPIs, respectively. The inhalation flow against time was recorded to provide the peak inhalation flow (PIF; in L/min), the maximum pressure change (ΔP; in kPa), acceleration rates (ACCEL; in kPa/sec), time to maximum inhalation, the length of each inhalation (in sec), and the inhalation volume (IV; in liters) of each inhalation maneuver. RESULTS: PIF, ΔP, and ACCEL values were consistent with the order of the inhaler's resistance. For each device, the inhalation characteristics were in the order ADULT>COPD>CHILD for PIF, ΔP, and ACCEL (p<0.001). The results showed a large variability in inhalation characteristics and demonstrate the advantages of ΔP and ACCEL rather than PIFs. Overall inhaled volumes were low, and only one patient achieved an IV >4 L and ΔP >4 kPa. CONCLUSION: The large variability of these inhalation characteristics and their range highlights that if inhalation profiles were used with compendial in vitro dose emission measurements, then the results would provide useful information about the dose patients inhale during routine use. The inhalation characteristics highlight that adults with asthma have greater inspiratory capacity than patients with COPD, whereas children with asthma have the lowest. The significance of the inhaled volume to empty doses from each device requires investigation.
Authors: Rain Jõgi; Satu Lähelmä; Mikko Vahteristo; Anita Happonen; Jussi Haikarainen Journal: J Aerosol Med Pulm Drug Deliv Date: 2018-10-09 Impact factor: 2.849
Authors: Giorgio Walter Canonica; Jan Arp; Johan René Keegstra; Henry Chrystyn Journal: J Aerosol Med Pulm Drug Deliv Date: 2015-09-09 Impact factor: 2.849
Authors: Janine A M Westerik; Victoria Carter; Henry Chrystyn; Anne Burden; Samantha L Thompson; Dermot Ryan; Kevin Gruffydd-Jones; John Haughney; Nicolas Roche; Federico Lavorini; Alberto Papi; Antonio Infantino; Miguel Roman-Rodriguez; Sinthia Bosnic-Anticevich; Karin Lisspers; Björn Ställberg; Svein Høegh Henrichsen; Thys van der Molen; Catherine Hutton; David B Price Journal: J Asthma Date: 2016-01-26 Impact factor: 2.515
Authors: Henry Chrystyn; David B Price; Mathieu Molimard; John Haughney; Sinthia Bosnic-Anticevich; Federico Lavorini; John Efthimiou; Dawn Shan; Erika Sims; Anne Burden; Catherine Hutton; Nicolas Roche Journal: BMC Pulm Med Date: 2016-01-14 Impact factor: 3.317