title: Comparison of flow rates produced by two frequently used manual hyperinflation circuits: a benchtop study.
abstract: BACKGROUND
  Manual hyperinflation is a treatment technique commonly used by physiotherapists in intensive care units to reverse or prevent atelectasis and mobilize airway secretions in intubated patients. The aim of this study was to determine which of the Magill (Rusch Manufacturing Ltd, Craigavon, UK) or Mapleson-C (CIG DF 655, CIG Medishield, Sydney, Australia) manual hyperinflation circuits was theoretically more effective at mobilizing secretions.
  
  
  METHODS
  A semi-blinded crossover study of 12 physiotherapists with tertiary level intensive care unit experience was conducted on a benchtop model. The order of circuits and compliance settings was randomized.
  
  
  RESULTS
  The Mapleson-C circuit produced a significantly faster peak expiratory flow (F[1, 210]=14.51, P < or = .01) and smaller inspiratory to expiratory flow ratio (F[1, 210]=28.44, P < or = .01) than the Magill circuit regardless of compliance settings.
  
  
  CONCLUSIONS
  The results of this study suggest that the Mapleson-C manual hyperinflation circuit may be more effective at mobilizing secretions.
authors: University of Queensland, Australia.
authors: Alison M
authors: AM
authors: Jones
authors: Peter J
authors: PJ
authors: Thomas
authors: Jennifer D
authors: JD
authors: Paratz
mesh_terms: D000328:Adult; D018592:Cross-Over Studies; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D026741:Physical Therapy Modalities / Q000295:instrumentation*; D011175:Positive-Pressure Respiration; D012016:Reference Values; D012121:Respiration, Artificial / Q000295:instrumentation*; D013990:Tidal Volume