Inhaled Sevoflurane for ARDS Prevention

Inclusion Criteria: 1. Age ≥ 18 years 2. Admitted to participating ICUs with at least one known risk factor for ARDS and a LIPS equals to, or greater than, 4 (Appendix D)105 3. Patient under invasive mechanical ventilation 4. With expected duration of sedation superior or equal to 4 hours 5. Affiliation to the French Sécurité Sociale Exclusion Criteria: * Patient under judicial protection, guardianship or supervision, as defined by art L1121-8 of the Public Health Code * Patient under psychiatric care as defined by art. L1121-6 of the Public Health Code * Patient deprived of their freedom by judiciary or administrative order * Known pregnancy * Presence of ARDS prior to randomization * Endotracheal ventilation for greater than 24 hours prior to randomization * Home mechanical ventilation (non-invasive ventilation or via tracheotomy) except for CPAP/BIPAP used solely for sleep-disordered breathing * Tidal volume of 6 mL/kg predicted body weight (PBW) below 200 mL (i.e. height inferior to 134cm for a man and 139cm for a woman) * Moribund patient, i.e. not expected to survive 24 hours despite intensive care * Previous hypersensitivity or anaphylactic reaction to sevoflurane or to the intravenous sedation agent routinely used in the participating ICU (such as midazolam, propofol, or dexmedetomidine) * Absolute contra-indications to the intravenous sedation agent routinely used in the participating ICU (such as midazolam, propofol, or dexmedetomidine) * Medical history of malignant hyperthermia * Long QT syndrome at risk of arrhythmic events * Medical history of liver disease attributed to previous exposure to a halogenated agent (including sevoflurane) * Suspected or proven intracranial hypertension * Enrollment in another interventional trial with direct impact on oxygenation