RÉSUMÉ
BACKGROUNDS: Metabolic and environmental evaluation can provide a powerful tool for management of patients with urolithiasis. We developed the interpretative reporting system of the analysis of urine stone risk and evaluated the clinical usefulness of this system. METHODS: The analysis of urine stone risk with thirty five cases were performed at Samsung Medical Center from January 1 to June 30, 1999. They were studied using a protocol based on 24 hour urine tests including volume, pH, sodium, potassium, chloride, calcium, phosphate, uric acid, magnesium, citrate, oxalate, ammonium and creatinine. Nitroprusside-cyanide spot test, routine urine analysis, urine culture, and several serum tests including electrolytes, calcium, phosphate, uric acid, creatinine, alkaline phosphatase, parathyroid hormone were also included. The results of physical and chemical analysis of urine stone were considered together. Relative supersaturations were estimated using software program EQUIL. We provided comprehensive interpretation about the specific causes and risks of stone formation in each patient. RESULTS: Hyperoxaluria (57.1%), hypercalciuria (57.1%), natriuresis (51.4%) and hypocitraturia (34.3%) were commonly found at the urine of patients with urolithiasis. The results of urine stone risk analysis based on relative supersaturation and related laboratory findings correlated well with the results of urine stone analysis. Mixed form of calcium oxalate stone was most commonly encounterd. Increased supersaturation with respect to calcium oxalate stone was noted in 23 cases (65.7%), which were frequently accompanied by hyperuricosuria or increased supersaturation with uric acid stone. The pH of urine was generally increased in struvite stones and decreased in uric acid stones. CONCLUSIONS: Analysis of urine composition and determination of urine stone risk were very useful for evaluation of patients with urolithiasis. And the interpretative reporting system of the analysis of urine stone risk can provide meaningful information in the treament and prevention of stone disease.