Nephrology Question 30 Instructor

If a patient presents with nephrolithiasis and the following urinalysis, what type of stone would you suspect? How would you manage this patient?


Calcium oxalate dihydrate – enveloped shaped crystals

Calcium oxalate monohydrate – dumbbell, spindle shaped crystals

The mainstain of treatment of calcium oxalate stones is to increase fluid intake to reach the goal of at least 2 L of urine output per day. A reduction in calcium excretion by a low sodium diet (80-100 meg/day) may also be suggested. Low sodium excretion will enhance proximal sodium and calcium absorption, thereby decreasing urinary calcium excretion and stone formation.

Drug therapy can also be added depending on the cause. If there is hypercalciuria, thiazide diuretics may be helpful. Potassium citrate can be used in cases of hypocitraturia and type 1 renal tubular acidosis. For hyperuricosuria, treatment of choice would be allopurinol or potassium citrate.

For additional information, try this free full text reference:

Ross Morton, Eduard A. Iliescu, and James W.L. Wilson.
Nephrology: 1. Investigation and treatment of recurrent kidney stones. CMAJ, Jan 2002; 166: 213 – 218 (PubMed)

Subscribe to Pearls

Uncle Sam wants you to subscribe to Medical Pearls

Subscribe today! It’s always free, and you can easily unsubscribe at any time. We will never share your email address. Subscribe to...

Multiple Pearls
Cardiology Pearls
Endocrinology Pearls
Hematology Pearls
Nephrology Pearls
Rheumatology Pearls
Transplant Pearls
General Internal Medicine Pearls
Instructor Pearls

Subscribe to receive your pearls today—it's free!