Selecting the Best Ventilator Hyperinflation Settings

Not Applicable

Completed

• Conditions: Respiration Disorders; Respiratory Failure
• Interventions: Other: PSV10; Other: PC-CMV3; Other: PSV25; Other: VC-CMV20; Other: PC-CMV1; Other: VC-CMV50

• Registration Number: NCT03327610
• Lead Sponsor: Centro Universitário Augusto Motta

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.

Study Timeline

• Study Start: 2016-07
• Primary Completion: 2017-08
• Study Completion: 2017-08
• Status Verified: 2017-10
• Study First Submitted: 2017-10-27
• Study First Submitted QC: 2017-10-27
• Last Update Submitted: 2017-10-27
• Study First Posted: 2017-10-31
• Last Update Posted: 2017-10-31

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 30

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
PSV10	PSV10	Application of a ventilator hyperinflation intervention with Pressure Support Ventilation (PSV) with a cycling off of 10% of peak inspiratory flow.
PC-CMV3	PC-CMV3	Application of a ventilator hyperinflation intervention with Pressure Control Continuous Mandatory Ventilation (PC-CMV1) with an inspiratory time of 3 seconds.
PSV25	PSV25	Application of a ventilator hyperinflation intervention with Pressure Support Ventilation (PSV) with a cycling off of 25% of peak inspiratory flow.
VC-CMV20	VC-CMV20	Application of a ventilator hyperinflation intervention with Volume Control Continuous Mandatory Ventilation (VC-CMV) with an inspiratory flow of 20Lpm.
PC-CMV1	PC-CMV1	Application of a ventilator hyperinflation intervention with Pressure Control Continuous Mandatory Ventilation (PC-CMV1) with an inspiratory time of 1 second.
VC-CMV50	VC-CMV50	Application of a ventilator hyperinflation intervention with Volume Control Continuous Mandatory Ventilation (VC-CMV) with an inspiratory flow of 50Lpm.

Primary Outcome Measures

Name	Time	Method
Pulmonary expansion	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	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	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.	Ten minutes after the onset of intervention.	Dichotomous variable, defined as achieving a difference higher than 17Lpm.

Secondary Outcome Measures

Name	Time	Method
Mean arterial pressure	Ten minutes after the onset of intervention.	Mean arterial pressure verified using the multi-parameter monitor.
Heart Rate	Ten minutes after the onset of intervention.	Heart rate verified using the multi-parameter monitor.