The use of EQUIL 2 in the clinical management of patients with stones

  • L. H. Smith
Conference paper
Part of the Fortschritte der Urologie und Nephrologie book series (2824, volume 25)


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.


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Copyright information

© Dr. Dietrich Steinkopff Verlag, GmbH & Co. KG., Darmstadt 1987

Authors and Affiliations

  • L. H. Smith
    • 1
  1. 1.Division of Nephrology and Internal MedicineMayo Clinic and Mayo FoundationRochesterUSA

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