Respiratory Disorders, Respiratory Failure
Conditions
Keywords
mechanical ventilation, physiotherapy, ventilator hyperinflation, airway clearance technique
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, 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.
Interventions
DEVICEBaseline Mechanical Ventilation
The subjects will be kept in Volume Control Continuous Mandatory Ventilation (VC-CMV).
DEVICEVHI With Inspiratory Pause
Application of a ventilator hyperinflation intervention with Volume Control Continuous Mandatory Ventilation (VC-CMV) with an inspiratory pause.
DEVICEVHI Without Inspiratory Pause
Application of a ventilator hyperinflation intervention with Volume Control Continuous Mandatory Ventilation (VC-CMV) without an inspiratory pause.
Sponsors
Universidade Federal do Rio de Janeiro
Centro Universitário Augusto Motta
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
DOUBLE (Investigator, Outcomes Assessor)
Intervention model description
Crossover Assignment
Eligibility
Sex/Gender
ALL
Age
18 Years to 90 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Cardiac Output | Baseline (before) and 10 minutes after the onset of VHI modesBasel | Estimation of cardiac output variation using thoracic bioimpedance |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Vascular pulmonary resistance | Baseline (before) and 10 minutes after the onset of VHI modes | Estimation of vascular pulmonary resistance variation using thoracic bioimpedance |
| Change in Systolic Volume | Baseline (before) and 10 minutes after the onset of VHI modes | Estimation of systolic volume variation using thoracic bioimpedance |
| Change in Mean Arterial Pressure | Baseline (before) and 10 minutes after the onset of VHI modes | Recording of mean arterial pressure variation using an automatic noninvasive device |
| Change in Cardiac Index | Baseline (before) and 10 minutes after the onset of VHI modes | Estimation of cardiac index variation using thoracic bioimpedance |
| Change in Cardiac Index II | Baseline (before) and 5 minutes after the end of VHI modes | Estimation of cardiac index variation using thoracic bioimpedance |
| Change in Vascular pulmonary resistance II | Baseline (before) and 5 minutes after the end of VHI modes | Estimation of vascular pulmonary resistance variation using thoracic bioimpedance |
| Change in Systolic Volume II | Baseline (before) and 5 minutes after the end of VHI modes | Estimation of systolic volume variation using thoracic bioimpedance |
| Change in Mean Arterial Pressure II | Baseline (before) and 5 minutes after the end of VHI modes | Recording of mean arterial pressure variation using an automatic noninvasive device |
| Change in Cardiac Output II | Baseline (before) and 5 minutes after the end of VHI modes | Estimation of cardiac output variation using thoracic bioimpedance |
Countries
Brazil
Outcome results
None listed