The use of EQUIL 2 in the clinical management of patients with stones
Current data support the concept that the formation of stones within the urinary tract are due to multiple factors. These include solute excess, supersaturation for the precipitating crystalline phase, matrix, inhibitors of crystal formation, heterogeneous nucleation, site of crystal formation and retention, phase transformation, infection and obstruction (1). Since supersaturation for the precipitating crystalline phase must always be present, and current forms of therapy, at least in part, are effective by reducing this supersaturation, the relative supersaturation ratio which takes into account a number of urinary components and their relationships has been used both clinically and experimentally by some workers (2,3). We have recently described a modified version of the FORTRAN program EQUIL that calculates the supersaturation in urine for the important mineral components in kidney stones (4). This program is written in BASIC language making it usable on most of the small, inexpensive microcomputers currently available as well as minicomputers and mainframes. In this presentation, application of EQUIL 2 in the evaluation and treatment of patients with calculus formation within the urinary tract will be discussed. The method of computation makes use of thermodynamic stability constants to calculate free ion activities for urinary ions. These free ions activities are used to calculate supersaturation ratio for the various solid phases. Input including urine pH and total concentrations in moles per liter of sodium, potassium, chloride, calcium, phosphate, sulfate, oxalate, citrate, urate, ammonia, CO2 content and pyrophosphate are needed.
Unable to display preview. Download preview PDF.
- 1.Smith LH (1984) Physicochemical factors in calcium oxalate urolithiasis. In: Robinson R (ed) (IXth International Congress of Nephrology) Nephrology, Vol 2. Springer-Verlag, New York, pp 990–998Google Scholar
- 2.Finlayson B (1977) Calcium stones: Some physical and clinical aspects. In: David DS (ed) Calcium Metabolism in Renal Failure and Nephrolithiasis. John Wiley & Sons, New York, pp 337–382Google Scholar
- 5.Smith LH, Werness PG (1983) Hydroxyapatite–The Forgotten Crystal in Calcium Urolithiasis. Trans Am Clin Climatol Assoc 95: 183–190Google Scholar