[Neonatal Bartter syndrome's special features in very premature newborns].

Neonatal Bartter syndrome is a rare condition, usually revealed by alkalosis and hypokalemia. Clinical and biological signs of neonatal Bartter syndrome are quite different from those encountered when this disease is diagnosed in older children. Diagnosis of neonatal Bartter syndrome is even more difficult in very preterm infants. The aim of this study was to highlight specific clinical and biological signs that may help direct physicians towards the diagnosis of neonatal Bartter syndrome when premature infants present with an atypical renal tubular disorder. Our case reports focus on excessive diuresis with elevated renal sodium excretion and severe dehydration. Correcting tubular disorders early may help avoid dehydration in the fragile preterm newborn.