The role of metabolic acidosis in causing uremic hyperphosphatemia.

Metabolic acidosis was corrected within 1 h in 7 chronic anuric uremic patients on maintenance hemodialysis and, in the course of a week, in 11 other patients on conservative therapy. These patients were on a diet supplying constant amounts of phosphate throughout the duration of the study. In the former group the intravenous infusion of sodium bicarbonate was used, and, in the latter, the oral administration of sodium citrate. In both groups serum phosphate was found to decrease significantly. In the patients on conservative therapy, phosphaturia also had significantly decreased while no changes occurred in their daily fecal loss of phosphate that was measured in 3 patients. These findings indicate that metabolic acidosis is one of the causes of hyperphosphatemia in chronic uremic patients.