Metabolic Evaluation

Metabolic evaluation may prevent stone recurrence, is economically sound yet vastly underused.

In first time stone formers conservative therapy with dietary advice is cost-effective. In recurrent stone formers however, medical therapy significantly reduces recurrence and is cost effective.

1. Basic metabolic evaluation (for every stone former)
   • Medical history including dietary intake
   • Urine test: urinalysis and urine pH
   • Blood test: RFT, calcium, uric acid level
   • Stone analysis
        
2. Comprehensive metabolic evaluation (for high risk stone former)
   1. Indications
      Recurrent stone former
      Young stone formers (under 30)
      >1 significant stone at presentation
      Stone type: Non-calcium urinary tract stones (infection stones, uric acid stones, cystine stone)
      Predisposing medication conditions: Gout, DM, obesity, hyperparathyroidism, GI disease
      Strong family history
         
   2. In addition to basic metabolic work-up, 24-hour urine analysis is necessary to identify predisposing factors for recurrent kidney stones.
         
   3. 24 hour urine analysis usually includes the assessment of:
      total volume, urine pH, creatinine, sodium, calcium , oxalate, uric acid and citrate