title: Intrapulmonary effects of setting parameters in portable intrapulmonary percussive ventilation devices.
abstract: BACKGROUND
  Despite potential benefits of intrapulmonary percussive ventilation (IPV) in various respiratory diseases, the impact of setting parameters on the mechanical effects produced by IPV in the lungs is unknown. We hypothesized that changing the parameters on IPV would modulate  these effects. This in vitro study aimed at comparing the changes in intrapulmonary effects resulting from changes in parameters in 3 portable IPV devices (IMP2, Impulsator, and Pegaso).
  
  
  METHODS
  Parameters were set in 72 combinations of frequency (90-250 cycles/min), inspiratory to  expiratory (I/E) time ratio (from 1/2 to 3/1), and pressure (10-60 cm H(2)O). Four resulting effects were recorded on a test lung via a pneumotachometer: the expiratory to inspiratory flow ratio (E/I flow ratio), the PEEP, the ventilation, and the percussion. Percussion was  assessed by the end-slope of the pressure curve. Analysis of variance was used for data analysis.
  
  
  RESULTS
  E/I flow ratio increased with increasing I/E time ratio (P < .001). The Pegaso produced the lowest E/I flow ratio. PEEP raised 6 cm H(2)O in both IMP2 and Impulsator,  and 17 cm H(2)O in the Pegaso with increasing frequency (P < .01), pressure, and I/E time ratio (P < .001). In all devices, ventilation increased with increasing pressure and decreasing frequency (P < .001). Percussion increased with increasing frequency  and decreasing I/E time ratio (P < .001), and with increasing pressure when I/E time ratio was 1/1 or less. The Pegaso provided the poorest percussion.
  
  
  CONCLUSIONS
  This study suggests that changing the parameters considerably modulates the mechanical effects produced by portable  IPV devices in the lungs. Increasing frequency increased PEEP and percussion, but decreased ventilation. Increasing I/E time increased PEEP and E/I flow ratio, and decreased percussion. Finally, increasing pressure increased PEEP and ventilation. The Pegaso produced the highest PEEP, least  percussion, and smallest change in E/I flow ratio.
authors.affiliation: Acute Neurorespiratory Rehabilitation Unit, Neuromuscular Excellency Centre, Vrije Universiteit Brussel-Inkendaal and Centre for Home Mechanical Ventilation, Ziekenhuis Inkendaal Rehabilitation Hospital, Brussels, Belgium. michel.toussaint@inkendaal.be
authors.forename: Michel
authors.initials: M
authors.lastname: Toussaint
authors.forename: Marie-Charlotte
authors.initials: MC
authors.lastname: Guillet
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Paternotte
authors.forename: Philippe
authors.initials: P
authors.lastname: Soudon
authors.forename: Jurn
authors.initials: J
authors.lastname: Haan
mesh_terms: D000403:Airway Resistance / Q000502:physiology; D004867:Equipment Design; D006612:High-Frequency Ventilation / Q000295:instrumentation*; D006801:Humans; D008954:Models, Biological; D012123:Pulmonary Ventilation / Q000502:physiology*; D015656:Respiratory Mechanics / Q000502:physiology*; D012122:Ventilators, Mechanical