Preventive Strategies in Acute Respiratory Distress Syndrome (ARDS)

Study Overview
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Brief Summary
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The investigators hypothesis is that patients at risk of ARDS, detected by LIPS (Lung Injury Prediction Score), under mechanical ventilation could benefit from a protective ventilatory strategy (used in ARDS treatment) in order to avoid or decrease the ARDS development. This would lead to a decrease in incidence, mortality and health care costs associated to this syndrome. This study will help to confirm the current evidence about low tidal volumes, evaluating adverse events of this strategy.

Detailed Description
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The main objective is to evaluate the effect of a protective ventilatory strategy by using lower tidal volumes compared to the use of traditionally volumes in ARDS development.

Official Title
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Preventive Strategies in Acute Respiratory Distress Syndrome

Conditions
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ARDS

Intervention / Treatment
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* Behavioral: Protective mechanical ventilation
* Behavioral: Control group
* Other: Dead space


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients within 12 hours after start of invasive mechanical ventilation (MV) and admitted to participating ICU (it is recommended an inclusion as soon as possible during the first 3 hours). LIPS > 4 points. Absence of mild, moderate and severe ARDS criteria (Berlin definition). Older than 18 year-old. Signed informed consent Exclusion Criteria: Bilateral pulmonary infiltrates in chest X-ray at admission. Mechanical ventilation > 12 hours. Previous pneumonectomy or lobectomy. Severe cranial trauma (Glasgow Coma Scale<9) or cranial hypertension. Severe chronic pulmonary disease (GOLD IV). Admission from other hospital under MV. Limitation of therapeutic effort. Pregnancy. Acute pulmonary embolism. Participation in other interventional trials. Previous randomized in the proposed trial. Absence of informed consent.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Protective ventilation arm<br>Low tidal volumes (from 4 to 6 milliliters(mL)/kilogram (kg) of predicted body weight (PBW) Plateau pressure less than 25 centimeter of water (cmH2O) Minimum PEEP of 5 cmH2O. | Behavioral: Protective mechanical ventilation<br>* Ventilation mode: volume control, pressure control, dual modes (It is allowed to change to a spontaneous mode; a minimum of 5 cmH2O level of support should be used; in case the resulting tidal volume exceeds 6 mL/kg PBW this is accepted. This is not a reason to use more sedation and/or muscle relaxants, or to switch the ventilator to a controlled mode of ventilation). Tidal volume: 6 mL/Kg PBW, decreasing 1 mL/kg PBW each step if necessary (steps of 5 minutes), to maintain plateau pressure < 25 cmH2O until a minimum tidal volume of 4 mL/Kg PBW, unless the patient suffers from severe dyspnea or unacceptable acidosis. Fraction of inspired oxygen inspired oxygen fraction (FiO2) > 0.21 to maintain oxygen saturation 90-92%. PEEP ≥ 5 cmH2O, and optimized to maintain Oxygen saturation (SpO2) 90-92% (left to the discretion of the attending physician). Plateau pressure ≤ 25 cmH2O<br>Other: Dead space<br>* Volumetric capnography will be used. Dead space (Vd/Vt) measurements will be taken at baseline and daily after initiation of mechanical ventilation. Nursing and respiratory care activities (including changes to ventilator settings) will be suspended for at least 5 minutes prior to all Vd/Vt measurements.<br>|
| Active Comparator: Control group<br>Traditional-sized tidal volumes (from 8 to 10 mL/kg PBW) Plateau pressure less than 25 cmH2O Minimum PEEP of 5 cmH2O. | Behavioral: Control group<br>* Ventilation mode: volume control, pressure control, dual modes (It is allowed to change to a spontaneous mode, with the level of support adjusted to reach tidal volumes minimum of 8 mL/kg predicted body weight PBW; if it is not possible, the data collection should be continue and an intention-to-treat analysis will be done). Tidal volume: minimum 8 mL/kg PBW. It is possible to increase until 10 mL/kg PBW unless plateau pressure increases above 25 cmH2O. · FiO2 > 0.21 to maintain oxygen saturation 90-92%. PEEP ≥ 5 cmH2O, and optimized to maintain SpO2 90-92% (left to the discretion of the attending physician). Plateau pressure ≤ 25 cm H2O.<br>Other: Dead space<br>* Volumetric capnography will be used. Dead space (Vd/Vt) measurements will be taken at baseline and daily after initiation of mechanical ventilation. Nursing and respiratory care activities (including changes to ventilator settings) will be suspended for at least 5 minutes prior to all Vd/Vt measurements.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| ARDS development | To determine the effect of a protective mechanical ventilation strategy using lower tidal volumes as compared to mechanical ventilation using traditionally-sized tidal volumes on development of ARDS. | 7 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mortality | In-hospital mortality, 28-day mortality and 90-day mortality | 90 days | 
| Ventilator-free days | From 1 to 28 days over 28 days in a month | 28 days after admission | 
| Dead space | Volumetric capnography | 7 days | 
| Length of stay | ICU stay and hospital stay | participants will be followed for the duration of ICU (Intensive Care Unit) and hospital stay, an expected average of 4 weeks | 
| Pneumonia | Incidence of pneumonia | 7 days | 
| Atelectasis | Incidence of atelectasis | 7 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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ARDS, Prevention, Protective mechanical ventilation, low tidal volumes