Specific Mechanical Power Assessment in Patients With Acute Respiratory Distress Syndrome

A helicoidal CT scanner will be used (Aquilion CXL, Toshiba, Japan), with AIDR 3D technique (Adaptive Iterative Dose Reduction 3D) in order to minimize exposure to X-rays. Two complete thorax CT scans will be performed, one of them in expiratory pause (PEEP) and the other in inspiratory pause (PPlat). Esophageal pressure shall be measured (FluxMed GrT, Argentina) and transpulmonary pressure will be calculated at the end of inspiration (Ppl-insp) and expiration (Ppl-exp).