Extensive Metabolic Evaluation refers to detailed testing to determine the specific chemical abnormality causing renal stones. This is not performed in most patients who have a single kidney stone or only an occasional recurrence.
Extensive Metabolic Evaluation is only necessary in some patients. The testing can be arduous and the results are of little value to most patients who do not have significant recurrent stones.
Patients who form numerous recurrent kidney stones, or present with extensive kidney stones on both sides should undergo a metabolic evaluation. Patients who present with their first stone at a young age or have a strong family history of calculi may also be suitable for detailed testing.
Extensive Metabolic Evaluation includes two 24-hour urine collections to determine the cause of their stone disease.
The urine is analysed for:
- Urine volume – low volume increases the risk of recurrence.
- Urine acidity (pH) – high acidity can cause uric acid stones.
- Calcium.
- Oxalate.
- Uric Acid.
- Citrate – this substance inhibits stone formation, low levels of Citrate in the urine may cause stones.
- Sodium.
- Potassium.
- Creatinine.