title: Appropriate use of a dry powder inhaler based on inhalation flow pattern.
abstract: BACKGROUND
  An optimal inhalation flow pattern is essential for effective use of a dry powder inhaler (DPI). We wondered whether DPI instructors inhale from a DPI with an appropriate pattern, and if not, whether self-training with visual feedback is effective.
  
  
  METHODS
  Subjects were 14 pharmacists regularly engaged in instruction in DPI use. A newly designed handy inhalation flow visualizer (Visual Trainer: VT) was used to assess inhalation profiles and to assist in self-training. With a peak inhalation flow rate (PIFR) > 50 L/min, time reaching PIFR (TPF) < 0.4 s, inhalation volume (VI) > 1 L, and flow at 0.3 s after the onset of inhalation (F0.3) > 50 L/min, the pattern was considered optimal.
  
  
  RESULTS
  Using Diskus or Turbuhaler 12 and 10 subjects respectively inhaled with a suitable PIFR. Those with a satisfactory F0.3were 10 and 7 respectively. The TPFwas short enough in only 1 and 2 respectively. All 14 subjects inhaled deeply (VI) through Diskus, and 10 did so through Turbuhaler. In the self-training session, only 3 subjects satisfied all three variables at the first trial, while 2 or 3 trials were required in other subjects. Among the three variables, optimal TPFwas the most difficult to attain. Once a satisfactory inhalation pattern was achieved using one DPI, eleven out of 12 subjects inhaled with a satisfactory pattern through the other DPI.
  
  
  CONCLUSIONS
  Visualization of the inhalation flow pattern facilitates the learning of proper inhalation technique through a DPI.
authors.affiliation: Department of Respiratory Medicine, Shonan Fujisawa Tokushukai Hospital, 1-5-1 Kandai, Tsujido, Fujisawa, Kanagawa 251-0041 Japan.
authors.forename: Tetsuri
authors.identifier: 0000-0001-5975-1886
authors.initials: T
authors.lastname: Kondo
authors.affiliation: Department of Respiratory Medicine, Shonan Fujisawa Tokushukai Hospital, 1-5-1 Kandai, Tsujido, Fujisawa, Kanagawa 251-0041 Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Hibino
authors.affiliation: Division of Respiratory Medicine, Atsugi Circulation Clinic, 3-5 Izumi-chou, Atsugi, Kanagawa 243-0013 Japan.
authors.forename: Toshimori
authors.initials: T
authors.lastname: Tanigaki
authors.affiliation: Department of Medicine, Stanford University, Stanford, CA 94305-2004 USA.
authors.forename: Stanley M
authors.initials: SM
authors.lastname: Cassan
authors.affiliation: Department of Medicine, Tokai University Oiso Hospital, 21-1 Gakkyo, Oiso, Kanagawa 259-0198 Japan.
authors.forename: Sakurako
authors.initials: S
authors.lastname: Tajiri
authors.affiliation: Department of Respiratory Medicine, Shonan Fujisawa Tokushukai Hospital, 1-5-1 Kandai, Tsujido, Fujisawa, Kanagawa 251-0041 Japan.
authors.forename: Kenichro
authors.initials: K
authors.lastname: Akazawa
keywords: Dry powder inhaler; Inhalation flow profile; Instruction; Self-training