Fig. 1 (abstract P264).

Within the first 24 hours of ICU admission (T1), patients will be evaluated with muscular ultrasonography comprehensive of diaphragm thickness and rectus femoris (medial vastus) cross-sectional area. At the same time, anthropometric measure will be collected (such as body height, ideal body weight, real body weight declared, right arm circumference) as well as BIVA measure (Xc, R, PA, lean body weight and % of extracellular body weight) and biochemical analysis (inclusive albumin, pre-albumin, blood count, lymphocyte count, magnesium, phosphorus, reticulocytes, renal and hepatic function test). The day after, the fluid balance will be calculated as well as the nitrogen balance. All the same measures will be repeated at day 3 (T3) and 7 days (T7)