A case of pseudo-Bartter's syndrome due to intestinal malrotation

Intestinal malrotation presenting beyond the neonatal period is associated with a multiplicity of symptoms, which are often non-specific and, consequently, are associated with delays in diagnosis. Pseudo-Bartter's syndrome, which mimics the manifestations of Bartter's syndrome, can be caused by a severe chloride deficiency secondary to vomiting, diarrhea, perspiration, diuretic abuse and so on. We describe a 6 year old boy who had been admitted to hospital three times during the preceding year. The patient lapsed into a critical condition with profound hypochloremia and hypokalemic metabolic alkalosis induced by extremely massive vomiting. The attacks of vomiting were spasmodic and self-limited. During the episodes of vomiting he fulfilled the criteria of pseudo-Bartter's syndrome, including hyperreninemia, hyperaldosteronism and normal blood pressure, but in the intervals between attacks he was completely asymptomatic. At the third admission, examination supported an overall clinical picture of bowel obstruction, which was confirmed by radiographic examination. Laparotomy revealed a midgut volvulus with intestinal malrotation. After surgery he made a good recovery and was symptom-free. In this patient, the high degree of hypochloremia and hypovolemia activated the renin-angiotensin-aldosterone system, then aldosterone promoted intensive reabsorption of sodium and excretion of potassium into the urine. Consequently the diagnosis of pseudo-Bartter's syndrome was establish on the basis of an extreme decrease in urinary chloride and an increase in urinary potassium concentration. It is relatively rare for vomiting due to intestinal malrotation to induce pseudo-Bartter's syndrome. The importance of considering this rare diagnosis in such cases is discussed.