PET - PEEP by EIT for Acute Respiratory Distress Syndrome Trial

Inclusion Criteria: Intubated, mechanically ventilated patients with diagnosis of ARDS according to ARDS Berlinstandard by attending doctor

Exclusion Criteria:

1. Age < 18 years old and > 90 years old;
2. Pregnancy;
3. EIT contradictions (presence of pacemaker or automatic implantable cardioverterdefibrillator);
4. Severe intracranial hypertension;
5. Pneumothorax, pneumomediastinum, subcutaneous emphysema or at high-risk forpneumothorax (e.g., pneumatocele, interstitial lung disease);
6. Unstable hemodynamic status intorerable to lung recruitment and PEEP titration, judgedby an attending intensivist; (This may be a transient criterion, since patientsmeeting this criterion might be included later if hemodynamics improves)
7. End status of disease;
8. Patients or their families refused to participate in the study