Selecting the Best Ventilator Hyperinflation Settings Based on Physiologic Markers: Randomized Controlled Study
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Respiratory Failure
- Sponsor
- Centro Universitário Augusto Motta
- Enrollment
- 30
- Primary Endpoint
- Pulmonary expansion
- Status
- Completed
- Last Updated
- 8 years ago
Overview
Brief 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.
Investigators
Fernando Silva Guimaraes
Associate Professor
Centro Universitário Augusto Motta
Eligibility Criteria
Inclusion Criteria
- •Patients under mechanical ventilation for more than 48h
Exclusion Criteria
- •mucus hypersecretion (defined as the need for suctioning \< 2-h intervals),
- •absence of respiratory drive,
- •atelectasis,
- •severe bronchospasm,
- •positive end expiratory pressure \> 10cmH2O,
- •PaO2-FiO2 relationship \< 150,
- •mean arterial pressure \< 60mmHg,
- •inotrope requirement equivalent to \>15 ml/h total of adrenaline and noradrenalin,
- •intracranial pressure \> 20mmHg
Outcomes
Primary Outcomes
Pulmonary expansion
Time Frame: Ten minutes after the onset of intervention.
Percentage of tidal volume above the normal tidal volume (estimated as 6mL/kg).
Peak inspiratory to expiratory flow ratio
Time Frame: Ten minutes after the onset of intervention.
Dichotomous variable, defined as achieving a peak inspiratory flow rate (PIFR) less than 90% of the peak expiratory flow rate (PEFR)
Peak expiratory flow higher than 40 Lpm
Time Frame: Ten minutes after the onset of intervention.
Dichotomous variable, defined as achieving a PEFR higher than 40 l/min
Difference between peak inspiratory and expiratory flows.
Time Frame: Ten minutes after the onset of intervention.
Dichotomous variable, defined as achieving a difference higher than 17Lpm.
Secondary Outcomes
- Mean arterial pressure(Ten minutes after the onset of intervention.)
- Heart Rate(Ten minutes after the onset of intervention.)