Bartter's syndrome

• Facts:
  Defective sodium reabsorption in thick ascending loop of Henle (TALH)
  
  Hypovolemia activates renin-angiotensin- aldosterone system and subsequent increased flow to distal tubule causes increased potassium and hydrogen ion secretion
  
  Together, leads to hypokalemia and metabolic alkalosis
• History / PE:
  Polydipsia, polyuria
  Growth abnormalities
• Diagnosis:
  Normotensive, hypokalemic, metabolic alkalosis (classic)
  Urine chloride concentration > 20 mEq/L
• See Also:
  Renin-angiotensin- aldosterone system
  Primary hyperaldosteronism (low PRA, high PA, HTN)
• Differential Diagnosis:
  Hypokalemic, alkalotic, NORMOtensive disorders
  1) Surreptitious vomiting (low urine chloride)
  2) Diuretic abuse
  3) Gitelman's syndrome (inherited defect in DCT, increased urine chloride)