Only patients enrolled in group A undergo to a lung ultrasound examination to assess the extent of pulmonary congestion, through its evidence of B-lines. B-lines originate from the contrast between air-filled structures and water-thickened pulmonary interlobular septa. This leads to linear echogenic vertical artefacts that spread from the pleural layers downwards in the screen. The ultrasound examination is performed with a handheld echocardiography device. The physician carries out a scan of the pulmonary fields, from basal towards mid and apical fields, through the midaxillary line while the patient lies supine. The quantification of B-lines is performed according to their extent over the lung fields. All the information are recorded in dedicated forms.