Selecting the Best Ventilator Hyperinflation Settings (VHI1)

Centro Universitário Augusto Motta

Status: Completed

Conditions: Respiration Disorders; Respiratory Failure

Treatments: Other: PSV10; Other: VC-CMV20; Other: PC-CMV1; Other: VC-CMV50; Other: PSV25; Other: PC-CMV3

Study type: Interventional

Funder types: Other

Identifiers

NCT03327610

VHI1

Details and patient eligibility

About

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.

Full 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.

Enrollment: 30 patients

Sex: All

Ages: 18 to 65 years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

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30 participants in 7 patient groups

BASELINE

No Intervention group

Description:

The subjects were kept in their current ventilatory mode.

VC-CMV20

Experimental group

Description:

Application of a ventilator hyperinflation intervention with Volume Control Continuous Mandatory Ventilation (VC-CMV) with an inspiratory flow of 20Lpm.

Treatment:

Other: VC-CMV20

VC-CMV50

Experimental group

Description:

Application of a ventilator hyperinflation intervention with Volume Control Continuous Mandatory Ventilation (VC-CMV) with an inspiratory flow of 50Lpm.

Treatment:

Other: VC-CMV50

PC-CMV1

Experimental group

Description:

Application of a ventilator hyperinflation intervention with Pressure Control Continuous Mandatory Ventilation (PC-CMV1) with an inspiratory time of 1 second.

Treatment:

Other: PC-CMV1

PC-CMV3

Experimental group

Description:

Application of a ventilator hyperinflation intervention with Pressure Control Continuous Mandatory Ventilation (PC-CMV1) with an inspiratory time of 3 seconds.

Treatment:

Other: PC-CMV3

PSV10

Experimental group

Description:

Application of a ventilator hyperinflation intervention with Pressure Support Ventilation (PSV) with a cycling off of 10% of peak inspiratory flow.

Treatment:

Other: PSV10

PSV25

Experimental group

Description:

Application of a ventilator hyperinflation intervention with Pressure Support Ventilation (PSV) with a cycling off of 25% of peak inspiratory flow.

Treatment:

Other: PSV25