RESPONSE TO FUROSEMIDE IN HYPERKALEMIC RENAL TUBULAR ACIDOSIS (RTA)

Hyperkalemic RTA in young children usually indicates renal or adrenal insufficiency, adrenal hyperplasia or a form of tubular resistance to mineralocorticoid. NH4Cl used to evaluate acidifying ability may augment pre-existing hyperkalemia to potentially dangerous cardiotoxic levels. An infant with profound neonatal metabolic alkalosis secondary to maternal psychogenic vomiting was found to have hyperkalemic RTA at two months of age. Lab values included, in mEq/L: Na 138, Cl 105, K 5.8, HCO3 18. BUN, blood sugar, serum creatinine and cortisol levels and BP were normal. Serum aldosterone (225 ng/ml) and plasma renin activity (20.1 ng/ml/hr) were high. Neither Florinef .1 mg/day nor Florinef + 4 days of supplemental NaCl 6 mEq/kg/day corrected the hyperkalemia, but renin and aldosterone levels dropped during this time. After Furosemide (F) 1 mg/kg IV: