The Role of Morphological Phenotype in ARDS

"Patients with ARDS were included. We excluded patients with emphysema, asthma, pneumothorax, or serious conditions of instability: oxygen saturation ≤ 88%; severe shock, ventricular arrhythmia, or myocardial ischemia.~To allow comparison between groups, patients were ventilated in volume control under similar conditions of tidal volume (TV; 6 ml/kg-PBW), plateau pressure (PPlat 30 cmH2O), respiratory rate (18 bit/min) and constant flow. PEEP was adjusted to reach objective PPlat.~Transpulmonary pressures (TP) were measured and a chest CT scan performed during an expiratory and inspiratory pause. Global and regional volumes of lungs were measured using specific software (Volume Analysis Software,Toshiba, Japan). Three regions were identified: basal (from the diaphragm to the carina), middle (from the carina to the aortic arch) and apical (above the aortic arch)."