The American journal of the medical sciences
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In patients with a normal plasma anion gap type of metabolic acidosis, knowledge of the rate of ammonium excretion can provide valuable information to determine if there is a renal cause for the disorder. Unfortunately, few hospital biochemistry laboratories offer routine determination of the urine ammonium concentration. ⋯ In a 24-hour urine collection, the relationship is urine ammonium equals -0.8 (urine anion gap) +82 (r = 0.97 p less than 0.01). The applications of this index of ammonium excretion are discussed.