Dissolution of uric acid calculi with intravenous 1/6 molar lactate.

The use of intravenous 1/6 molar sodium lactate for dissolution of uric acid calculi is reported in 4 patients. All presented with a urine pH of 5. The calculi were located in the proximal ureter in 2 patients and in the renal pelvis in the other 2 patients. After infusion of 1/6 molar lactate, rapid alkalinization of the urine to pH 8 was achieved and maintained. The mean time required for dissolution of the calculi was 6.2 days precluding the need for surgical intervention. The mechanism of action of lactate is oxidative conversion to bicarbonate, providing a sustained alkaline urine. While our patients experienced no metabolic complications, one should monitor serum electrolytes, blood pressure, and fluid balance, particularly in cardiac-compromised patients.