Stone disease



Recurrent stone formation is common, but people who have frequent early recurrences should be screened for risk factors.  Check:

Blood Renal function
Ca and PO4
Uric acid
HCO3
Urine Infection

Request 24h urine for ‘stone screen’ (Edinburgh labs), (plain bottle), to check volume, calcium, oxalate, Na, urate, cystine.  Note that creatinine and protein need to be requested separately.

Stone don’t forget to analyze the stone itself
Family history hypercalciuria, medullary sponge kidney, distal RTA, Dent’s disease
Drug history occasionally stones formed from drugs (including ephedrine)
Dietary assessment important.  See
Diet.

 

As for protein, urinary calcium can be measured as a ratio with creatinine, instead of a 24h clearance:

 
Ca/Creat ratio
 
Comment
Oxalate/Creatinine
< 0.6
Normal

< 50 micromol/mmol *
0.6 – 0.8
Equivocal
 
> 0.8
High
 

 

* After the age of 5 years.  Ratios are higher in infancy (
Matos et al 1999). 

Management principles

 

 

Important principles are common to most stones:

  • Maintain high urine volume, especially at night
  • Restrict dietary sodium
  • Maintain good dietary calcium intake, but avoid calcium supplements
  • Consider thiazide for hypercalciuria (avoid loop diuretics)
  • High Protein diet is associated with stones – reduce

 For management of individual metabolic abnormalities, seek specific information.

Further information

Patient information on
renal stones from
EdRenINFO

 

Acknowledgements:   Neil Turner was the main author for this page. The last modified date is shown in the footer.

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