Comparison of flow rates produced by two frequently used manual hyperinflation circuits: A benchtop study

BackgroundManual 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.MethodsA 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.ResultsThe Mapleson-C circuit produced a significantly faster peak expiratory flow (F[1, 210] = 14.51, P ≤ .01) and smaller inspiratory to expiratory flow ratio (F[1, 210] = 28.44, P ≤ .01) than the Magill circuit regardless of compliance settings.ConclusionThe results of this study suggest that the Mapleson-C manual hyperinflation circuit may be more effective at mobilizing secretions.