When Electrolytes Shocks You: Classical Bartter Syndrome (Type III) Presenting with Refractory Shock and Recurrent Extubation Failure in a 9Month-Old Infant.

Abstract

Bartter syndrome (BS) is a rare inherited renal tubular disorder characterized by hypokalemia, metabolic alkalosis, renal salt wasting, and secondary hyperreninemic hyperaldosteronism with normal or low blood pressure. The classical form (type III) is commonly present in infancy or early childhood but may demonstrate variable clinical features, leading to delayed diagnosis. A 9-month-old male infant was admitted with severe pneumonia and septic shock requiring mechanical ventilation. The child developed persistent hypokalemia, hyponatremia, and metabolic alkalosis despite appropriate correction, resulting in four episodes of extubation failure. Persistent dyselectrolytemia in the presence of normotension and inappropriate renal electrolyte losses raised suspicion of an 
underlying renal tubular disorder. Elevated plasma renin and aldosterone levels supported the diagnosis of classical BS. Stabilization of serum electrolytes resulted in successful extubation and clinical improvement. This case highlights the importance of considering BS in infants with refractory electrolyte imbalance and unexplained ventilator dependence, particularly when renal salt wasting is evident.