Lung ultrasound will be performed to diagnose EVLW. A Philips C5 ultrasound system (frequency 5Hz; Philips Medical Systems, Suresnes, France) with an ordinary echo probe will be used. Chest ultrasound will be performed using the 12 regions method. Intercostals spaces on each side will be examined anteriorly (midclavicular line), laterally (anterior axillary line) and posteriorly (posterior axillary line) Four ultrasound aeration patterns a. Normal aeration (N): 0 score ; line sliding sign associated with respiratory movement or less than 3 B lines ; b. Moderate loss of lung aeration: score 1 ; a clear number of multiple visible B-lines with horizontal spacing between adjacent B lines ≤ 7 mm (B7 lines) c. Severe loss of lung aeration: score 2; multiple B lines fused together that were difficult to count with horizontal spacing between adjacent B lines ≤ 3 mm (B3 lines); and d. Pulmonary consolidation: score 3; hyperechoic lung tissue, accompanied by dynamic air bronchogram.