Acute Respiratory Distress Syndrome
Conditions
Keywords
ARDS, cardiac output, ventilation perfusion ratio
Brief summary
Intro: The mortality of acute respiratory distress syndrome (ARDS) remains high (40%), and may be aggravated by ventilation-induced lung injury (VILI), the main mechanisms of which are: 1. Anterior region overdistension, 2. Atelectrauma in the posterior regions. Positive expiratory pressure (PEEP) adjusted on the ventilator during ARDS aims to recruit posterior pulmonary territories in order to limit atelectrauma but is accompanied by a concomitant risk of overdistension of anterior territories. Recent data suggest that continuous anterior chest compression (CACC) could limit the overdistension of the anterior regions by decreasing the compliance of the anterior chest wall and thus the regional transpulmonary pressure, while promoting the redistribution of ventilation to the posterior territories. The effects of CCAC on ventilation/perfusion ratios and hemodynamics are unknown. Hypothesis/Objective : The participants hypothesize that during ARDS, CCAC: 1. Improves ventilation/perfusion ratios by decreasing both anterior territory dead space effect and posterior territory shunt, 2. Induce an improvement in cardiac output by decreasing right ventricular afterload (decrease in capillary compression related to the overdistension of the anterior territories and decrease in hypoxic vasoconstriction of the condensed territories). Objective: Primary outcome : To evaluate the effects of CCAC on ventilation/perfusion ratios during moderate to severe ARDS. Secondary outcome : To evaluate the effects of CCAC on hemodynamics : left heart morphology, systolic and diastolic function, cardiac output, right heart morphology, systolic function, pulmonary hypertension, volemia. Method In patient with moderate to severe ARDS, CACC is performed manually and the pressure applied will be maintained between 60 and 80 cmH2O. Electrical impedance tomography of ventilation and perfusion will be used for the measurement of the percentage of areas with normal VA/Q ratios, areas of shunt and areas of dead space effect. Left heart morphology, systolic and diastolic function, cardiac output, right heart morphology, systolic function, pulmonary hypertension, volemia will be evaluated by using echocardiography.
Interventions
CACC is performed manually and the pressure applied will be maintained between 60 and 80 cmH2O.
Sponsors
Assistance Publique - Hôpitaux de Paris
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
OTHER
Masking
NONE
Intervention model description
Patient with moderate to severe ARDS under sedation and curarization keep on going
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Age ≥ 18 years * ARDS moderate to severe according to the Berlin criteria * Patient receiving continuous sedation and curarization * Free and informed consent from the patient or family member
Exclusion criteria
* Pregnancy * Adult patient subject to a legal protection measure (tutor, curator, etc.) * Patients with a pacemaker, automatic implantable cardioverter defibrillator, * Contraindications to thoracic belt placement (e.g., thoracic or spinal cord trauma, recent thoracic surgery) * Undrained pneumothorax, bronchopleural fistula * Hemodynamic instability (i.e., use of intravenous fluids of more than 10 mL/kg or vasopressors 2 mg/h of norepinephrine or 0.5 mg/h of epinephrine)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| percentage of areas with normal VA/Q ratios, areas of shunt and areas of dead space effect. | 28 days | demonstration that CACC may improve VA/Q ratio by using electrical impedance tomography |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| CACC may induce a modification in patient with right ventricular injury | 28 days | RV/LV : right ventricle end-diastolic ratio, to LV end-diastolic diameter ratio, sLV eccentricity index : systolic left ventricle eccentricity index; ACP : Acute cor pulmonale |
| CACC may induce a modification in right systolic function | 28 days | measurement of right systolic function paramaters : TAPSE (mm) , S' annular tricuspid wave (m/s), RVFAC (%) |
| CACC may induce a modification in cardiac output by decreasing right ventricular afterload | 28 days | measurement of cardiac output with echocardiography via : left ventricle outflow tract velocity time integral cm) |
| CACC may induce a modification in ventilation distribution | 28 days | ventilation distribution antero-posterior and right/left, assessed by electrical impedance tomography |
| CACC may induce a modification in lung perfusion distribution | 28 days | lung perfusion distribution antero-posterior and right/left assessed by electrical impedance tomography |
| CACC may induce a modification in left systolic function | 28 days | LVEF : left ventricular ejection fraction |
Countries
France
Outcome results
None listed