Ventilator Hyperinflation and Hemodynamics
Condition: Respiratory Failure; Respiratory Disorders
MeSH terms: Respiratory Insufficiency; Respiration Disorders; Respiratory Tract Diseases
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,
      the literature is scarce concerning its safety and adverse effects. Thus, the aim of this
      study is to compare the hemodynamic repercussions of VHI in volume-controlled mode. In a
      randomized, controlled and crossover design, 24 mechanically ventilated patients will undergo
      2 modes of ventilator hyperinflation (with and without an inspiratory pause) and a control
      intervention. Cardiac output, cardiac index, mean arterial pressure, pulmonary vascular
      resistance, systolic volume and other hemodynamic variables will be recorded 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, the literature is scarce concerning its safety and adverse effects. Thus,
      the aim of this study is to compare the hemodynamic repercussions of VHI in volume-controlled
      mode.

      Methods: in a randomized, controlled and crossover design, 24 mechanically ventilated
      patients will undergo 2 modes of ventilator hyperinflation (with and without an inspiratory
      pause of 2 seconds) and a control intervention. For the VHI interventions, the inspiratory
      flow will be set at 20 Lpm, and tidal volume will be increased until a peak pressure of
      40cmH2O is achieved. During the control intervention, the patients will remain in
      volume-control ventilation with an inspiratory flow = 60Lpm and tidal volume = 6mL/IBW. The
      interval between interventions (washout) will be of 10 minutes or more, according to the time
      needed to recover the cardiac index to baseline values (maximum difference of 10%). Cardiac
      output, cardiac index, mean arterial pressure, pulmonary vascular resistance, systolic volume
      and other hemodynamic variables will be recorded during the interventions by using impedance
      cardiography.
    

Intervention name(s): Baseline Mechanical Ventilation; VHI With Inspiratory Pause; VHI Without Inspiratory Pause
Intervention type(s): Device; Device; Device
Intervention description(s): The subjects will be kept in Volume Control Continuous Mandatory Ventilation (VC-CMV).; Application of a ventilator hyperinflation intervention with Volume Control Continuous Mandatory Ventilation (VC-CMV) with an inspiratory pause.; Application of a ventilator hyperinflation intervention with Volume Control Continuous Mandatory Ventilation (VC-CMV) without an inspiratory pause.
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Crossover Assignment
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: mechanical ventilation; physiotherapy; ventilator hyperinflation; airway clearance technique