Selecting the Best Ventilator Hyperinflation Settings
Condition: Respiratory Failure; Respiration Disorders
MeSH terms: Respiratory Insufficiency; Respiration Disorders
Study type: Interventional

Summary: 
      Ventilator hyperinflation (VHI) has been shown to be effective in improving respiratory
      mechanics, secretion removal, and gas exchange in mechanically ventilated patients; however,
      there are no recommendations on the best ventilator settings to perform the technique. Thus,
      the aim of this study was to compare six modes of VHI, concerning physiological markers of
      efficacy and safety criteria, in order to support the optimal VHI settings selection for
      mechanically ventilated patients. In a randomized, controlled and crossover study, 30
      mechanically ventilated patients underwent 6 modes of ventilator hyperinflation. The maximum
      expansion (tidal volume), expiratory flow bias criteria (inspiratory and expiratory flow
      patterns), overdistension (alveolar pressure), asynchronies and hemodynamic variables (mean
      arterial pressure and heart rate) were assessed during the interventions.
    

Detailed description: 
      Background: Ventilator Hyperinflation (VHI) has been shown to be effective in improving
      respiratory mechanics, secretion removal, and gas exchange in mechanically ventilated
      patients; however, there are no recommendations on the best ventilator settings to perform
      the technique. Thus, the aim of this study was to compare six modes of VHI, concerning
      physiological markers of efficacy and safety criteria, in order to support the optimal VHI
      settings selection for mechanically ventilated patients.

      Methods: In a crossover study, every included mechanically ventilated patient underwent six
      modes of VHI in a randomized order: Volume Control Continuous Mandatory Ventilation (VC-CMV)
      with inspiratory flow = 20Lpm (VC-CMV20), VC-CMV with inspiratory flow = 50Lpm (VC-CMV50),
      Pressure Control Continuous Mandatory Ventilation (PC-CMV) with inspiratory time = 1s.
      (PC-CMV1), PC-CMV with inspiratory time = 3s. (PC-CMV3), Pressure Support Ventilation (PSV)
      with cycling off = 10% of peak inspiratory flow (PSV10), and PSV with cycling off = 25% of
      peak inspiratory flow (PSV25). The maximum expansion (tidal volume), expiratory flow bias
      criteria (inspiratory and expiratory flow patterns), over-distension (alveolar pressure),
      asynchronies and hemodynamic variables (mean arterial pressure and heart rate) were assessed
      during the interventions.
    

Intervention name(s): VC-CMV20; VC-CMV50; PC-CMV1; PC-CMV3; PSV10; PSV25
Intervention type(s): Other; Other; Other; Other; Other; Other
Intervention description(s): Application of a ventilator hyperinflation intervention with Volume Control Continuous Mandatory Ventilation (VC-CMV). The inspiratory flow was set at 20Lpm and the tidal volume was increased in steps of 200mL until the peak airway pressure of 40cmH2O was achieved. After achieving the target pressure, this ventilatory regimen lasted 15 minutes. Positive end expiratory pressure and the inspired oxygen fraction were not modified.; Application of a ventilator hyperinflation intervention with Volume Control Continuous Mandatory Ventilation (VC-CMV). The inspiratory flow was set at 50Lpm and the tidal volume was increased in steps of 200mL until the peak airway pressure of 40cmH2O was achieved. After achieving the target pressure, this ventilatory regimen lasted 15 minutes. Positive end expiratory pressure and the inspired oxygen fraction were not modified.; Application of a ventilator hyperinflation intervention with Pressure Control Continuous Mandatory Ventilation (PC-CMV1). The inspiratory time was set at 1 second and the pressure control was increased until a peak pressure of 40cmH2O was achieved. After achieving the target pressure, this ventilatory regimen lasted 15 minutes. Positive end expiratory pressure and the inspired oxygen fraction were not modified.; Application of a ventilator hyperinflation intervention with Pressure Control Continuous Mandatory Ventilation (PC-CMV1). The inspiratory time was set at 3 seconds and the pressure control was increased until a peak pressure of 40cmH2O was achieved. After achieving the target pressure, this ventilatory regimen lasted 15 minutes. Positive end expiratory pressure and the inspired oxygen fraction were not modified.; Application of a ventilator hyperinflation intervention with Pressure Support Ventilation (PSV). The cycling off was set at 10% of peak inspiratory flow and the pressure support was increased until a peak pressure of 40cmH2O was achieved. After achieving the target pressure, this ventilatory regimen lasted 15 minutes. Positive end expiratory pressure and the inspired oxygen fraction were not modified.; Application of a ventilator hyperinflation intervention with Pressure Support Ventilation (PSV). The cycling off was set at 25% of peak inspiratory flow and the pressure support was increased until a peak pressure of 40cmH2O was achieved. After achieving the target pressure, this ventilatory regimen lasted 15 minutes. Positive end expiratory pressure and the inspired oxygen fraction were not modified.
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: Respiratory Therapy; Positive Pressure Respiration; Physical Therapy Modalities