Please select the eligibility criteria that correspond to the clinical trial below.
Title: Comparison of Two Strategies for Setting Positive End-Expiratory Pressure in Acute Lung Injury/ Acute Respiratory Distress Syndrome (ExPress Study).
Brief Summary: The aim of this multicenter randomized controlled trial is to compare the impact on mortality of patients mechanically ventilated for acute lung injury or acute respiratory distress syndrome of two strategies for setting end-expiratory pressure.


Options:
A: Inclusion Criteria:

* Early Acute Respiratory Distress Syndrome
* PaO2/FiO2 \< 150 mm Hg at PEEP ≥ 8 cm H2O
* Age 18-75 years
* Body weight \> 40 kg

Exclusion Criteria:

* More than 1 chest tube/hemithorax with persistent airleak for \> 72 h)
* Systolic pressure \< 90 mm Hg with fluids/norepinephrine at ≥ 0.5 μg/kg/min
* Heart disease (defined in Detailed Description)
* Chronic obstructive pulmonary disease (defined in Detailed Description)
* Intracranial abnormalities (any cause of intracranial pressure \> 20 mm Hg)
* Chronic interstitial lung disease
* Lung biopsy or resection on current admission
* Previous lung or bone marrow transplant or immunosuppression
* Pregnancy or morbid obesity
* Inability to wean from prone positioning or inhaled nitric oxide
* Enrollment in another interventional study
B: Inclusion Criteria:

1. Adult patients aged 18 years or more, both gender
2. Receiving endotracheal intubation and mechanical ventilation for less than 36 hours
3. Presenting with a Severe ARDS :

   * Acute onset
   * PaO2/FiO2 ≤ 200 (≤ 26.7 kPa)
   * Bilateral pulmonary infiltrates on frontal chest radiography
   * Capillary wedge pressure \< 18 mm Hg if measured or no evidence for left atrial hypertension
4. During since 12-24 hours
5. AND with severity criteria : PaO2/FiO2 \< 150 mm Hg (\< 20 kPa) under FiO2 ≥ 0.6, PEEP ≥ 5 cm H2O and a tidal volume equal to 6 ml/kg PBW.
6. Written consent from patient's next of kin

Exclusion Criteria:

1. contra-indication to the prone position

   * Intracranial pressure \> 30 mm Hg or cerebral perfusion pressure \< 60 mm Hg
   * Massive haemoptysis needing urgent surgical or radiological treatment
   * Tracheal or thoracic surgery in the last 15 days
   * Facial trauma or surgery in the last 15 days
   * Deep venous thrombosis or pulmonary embolism treated in the last 2 days
   * Cardiac pace maker implantation in the last 2 days
   * Unstable bone dislocations of rachis, femur, rib cage, pelvis
   * Mean systolic arterial pressure less than 70 mm Hg despite vasopressive therapy
   * Pregnancy
   * Bronchopleural fistula treated with a single anterior chest tube (risk of kinking in prone position)
2. Exclusion criteria for respiratory raisons

   * Necessity to use NOi or almitrine
   * Extra body circulation for oxygenation and/or CO2 epuration
3. Exclusion criteria linked to clinical context

   * Pulmonary transplantation
   * Burns ≥ 20% of body surface
   * Chronic respiratory insufficiency under home oxygen therapy or non invasive ventilation
   * Chronic disease supposed to be fatal in less than 1 year
   * Non invasive ventilation for more than 24 hours before enrollment
4. Other exclusion criteria

   * Decision to stop life-supportive therapies before enrollment
   * Enrollment in an other trial testing an intervention and with mortality as primary end point in the last 30 days
   * Prior enrollment in the same study
   * Prone position before enrollment
C: Inclusion Criteria:

* Mechanical ventilation through an endotracheal tube
* Bilateral infiltrates consistent with pulmonary edema
* PaO2/FiO2 \< 300 mmHg
* No clinical evidence of left atrial hypertension. If measured, pulmonary artery occlusion pressure \< 18 mmHg
* Criteria 1, 2 et 3 jointly present for less than 48 hours
* Written informed consent obtained from the patient or surrogate

Exclusion Criteria:

* Age \< 18 years
* Pregnancy
* Expected duration of mechanical ventilation through an endotracheal tube \< 48 hours
* Participation in other trials within the previous 30 days
* Increased intracranial pressure
* Severe chronic respiratory disease
* Morbid obesity (weight \> 1kg/cm)
* Sickle cell disease
* Bone marrow transplant or chemotherapy-induced neutropenia
* Extended burns (\> 30 % total body surface area)
* Severe chronic liver disease (Child-Pugh score C)
* Pneumothorax
D: Inclusion Criteria:

* Patients receiving mechanical ventilation will be enrolled if they meet criteria for acute respiratory distress syndrome, with the PaO2/FiO2 ratio criterion modified as follows:

  * PaO2/FiO2 ratio ≤ 200 with 5 ≤ PEEP ≤ 10 cmH2O

Exclusion Criteria:

* Age \< 16 years.
* \> 72 hours since all inclusion criteria are met.
* Lung transplant, liver transplant or bone marrow transplant.
* Clinical or instrumental evidence of cerebral edema or elevated endocranial pressure.
* Conditions which are thought to contraindicate the use of prone positioning (i.e., not-stabilized bone fracture, column fracture, pelvis fracture, multiple rib fracture with chest-wall instability, severe haemodynamic instability).

Answer: C