Recurrence and Kidney Stone Prevention

After the acute episode (acute renal colic), management is directed toward prevention of stone recurrence by reducing risk factors associated with stone formation. Children who develop a kidney stone have a significant chance of developing stones in the future. Studies have estimated the chances to be between 30-65%. Therefore a thorough metabolic evaluation is strongly encouraged in children after their first presentation with urolithiasis. A 24-hour urinalysis for stone risk should be obtained including, at a minimum, urinary volume, pH, and calcium, creatinine, uric acid, citrate, oxalate, and magnesium levels.

The cornerstones for preventing stone recurrence as the child enters adulthood are the ability to render the patient stone free, elucidate and treat metabolic abnormalities, control urinary infection, and correct anatomic anomalies.

The number of steps can decrease the chances of developing another stone:

Drink more fluids - Drinking more fluids can help to decrease the risk of forming all types of kidney stones. The goal is to increase the amount of urine that flows through the kidneys and ureters and to lower the concentration of substances that promote stone formation.

Calcium - Children with increased levels of calcium in the urine should drink more fluids and make some changes in their diet:

· Eat a low-sodium diet

· Get the right amount of calcium from foods and drinks. Consuming too much calcium in foods and drinks is not recommended. However, the child should not stop eating foods and drinks with calcium because calcium is important in building strong bones.

The "right" amount of calcium depends on the child's age:

v 500 mg/day for children one to three years

v 800 mg/day for children four to eight years

v 1300 mg/day for children nine years and older

· Avoid calcium and vitamin D supplements

· Eat potassium-rich foods (fresh fruits and vegetables)

· If urine calcium levels are still high after three to six months of these changes, a medicine might be recommended.

Oxalate - Children who have high levels of oxalate in the urine should:

· Drink more fluids

· Avoid vitamin C supplements

· Avoid foods that contain large amounts of oxalate, including beet and turnip greens, rhubarb, strawberries, star fruit, sweet potatoes, wheat bran, tea, cocoa, pepper, chocolate, parsley, beets, spinach, dill, nuts, and citrus juices

Urate - Children with increased levels of urate in the urine should drink more fluids. Some children will be given a treatment to increase the pH of the urine (potassium citrate or potassium carbonate).

Cystine - Children with high levels of cystine in the urine should drink more fluids. Some children will be given a medicine that reduces the acidity (i.e., increases the pH) of the urine (potassium citrate or potassium carbonate).

Low citrate - Children who have a low level of citrate in the urine are usually given a treatment to increase citrate levels (potassium citrate or potassium bicarbonate).

Struvite - Struvite stones usually develop because of a urinary tract infection. Preventing future urinary tract infections can help to prevent struvite stones. This is discussed separately.

Complementary and alternative therapies — There are no data about the safety or benefit of complementary and alternate therapies for kidney stones in children (including herbs, homeopathy, acupuncture, and others). We do not recommend these therapies because they are unproven.