Chronic kidney disease (CKD) is a major health problem worldwide.(1) Chronic renal failure is defined as a decrease in glomerular filtration rate (GFR) of less than 60 ml/min/1.73 m2 of body surface evolving for more than 3 months . The etiologies of CKD in children are three main groups of pathologies: congenital anomalies of the kidney and urinary tract , hereditary nephropathies and acquired causes . (2) complication of pediatric hemodialysis is chronic fluid overload, left ventricular hypertrophy ,hypertension, heart failure, decrease arterial flexibility and often results in increase chance of morbidity and mortality, So fluid overload must be prevented .(3) Lung ultrasonography is the most recent, safe, easy, and reliable technique . The most commonly observed finding is a comet tail fanning out from the lung-wall interface and spreading upwards to the edge of the screen, named a "B-line" Chest sonar advantages include its noninvasiveness , ease of use, availability of portable machines, avoidance of radiation detect lung edema even in initial non symptomatic cases known as hidden lung congestion .(4) Bioimpedance analysis (BIA) Bio impedance spectroscopy (BIS) is a technique used to estimate total body water, extracellular water, lean and adipose tissue mass and over hydration . (5) N-terminal pro-brain natriuretic peptide is used as a biomarker to aid to predict cardiac dysfunction in children and adolescents .(6)it is an effective marker of volume status in patient with or without reduced ejection fraction undergoing hemodialysis. (7)
