RENAL (KIDNEY) STONES
Last Updated : 1/3/2011
Kumud P Mehta
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My child complains burning on & off, while passing urine. Also, he has backache. What to do?
Burning while passing urine and backache are symptoms of kidney problems, because kidneys are placed at the posterior abdominal wall on either side of spine. Commonly these symptoms occur due to urinary tract infection and in absence of fever,

renal stones

should be ruled out.

My child’s

urine examination

showed presence of plenty of crystals. However he has no complaints. What should I do?

If urine examination shows plenty of crystals, but the child has no complaints, there is no need to worry. But if there is family history of kidney stones, 24 hours urine excretion of calcium, uric acid, oxalate etc may be done to detect hypercalciuria, hyperuricosuria, hyperoxaluria, which are precursors of stone formation.

What are urinary stones? I thought stones were seen in adults. Does it occur in children?
Stones are formed when substances such as calcium, phosphate, uric acid, oxalate are in excess in urine, become insoluble and form concretions and settle on a matrix in tubules. Urinary infections can increase the size of these concretions and further harden them. Although stones are common in adults, they can occur in children.

How do these urinary stones occur?
Stones occur due to abnormal and excessive accumulation of stone forming substances in urine which are normally dissolved due to presence of substances which inhibit stones formation like citrate, pyrophosphates. If the concentration of calcium, oxalate, uric acid, cystine etc is very high and inhibitors are low, stone formation occurs. The abnormal metabolic disorders can be inherited e.g. Hypercalciuria, hyperoxaluria, cystinuria. Less intake of fluids, urinary infection, congenital anomalies of urinary tract with obstruction, hyperparathyroidism, RTA (renal tubular acidosis) are causes of renal calculi or stones.

How do I know whether my child is suffering from kidney stones?
Kidney stones can give rise to abdominal pain, hematuria (blood in urine), vomiting, backache, recurrent urinary tract infections or are accidentally discovered on USG (Ultrasonography).

How does one diagnose presence of renal stones?
Diagnosis is made by plain X-ray of kidneys, ureters and urinary bladder or ultrasonography.

My child’s X-rays showed no stones. However, the doctor says that he is suffering from kidney stones. Is it possible?
Some kidney stones are radiolucent i.e. cannot be seen on plain x-rays but can be diagnosed by Ultrasonography e.g. uric acid, cystine stones.Small stones pass out with high fluid intake, citrate treatment, alkali administration etc.

Is USG a must to do in a patients with kidney stones?
If a high degree of suspicion exists and plain X-rays do not show stones, USG is a must for diagnosis.

My child has a renal stone, However he has no complaints. Does he still have to get treated? Can’t we just leave him alone?
If the kidney stone (s) is small and is causing no complaints there is no need to treat. Periodic imaging(USG) is required to assess the size and whether it has moved from its location. However, a larger stone requires treatment as it may later cause complications like colic, renal damage etc.

What are the

complications of urinary stones

?

Complications of urinary stones are urinary infection and obstruction which may lead to destruction of renal parenchyma and if the stones are on both the sides, they may cause obstruction and destruction of both kidneys. In the long run, chronic renal failure (CRF) can occur.

Are kidney stones recurrent? How can I prevent it from occurring again?
Kidney stones can be recurrent. To prevent recurrence, it is advisable to drink large quantities of water, which does not allow accumulation of concretions. Use of inhibitors like citrate solution may help.

Most of the members of our family had stones some point in life. Is there something like a family history of stones? How is stone formation prevented?
Family history of renal stones helps in early diagnosis of certain metabolic disorders which are precursors for stone formation e.g. hypercalciuria which can be detected by 24 hours urine excretion of calcium. More than 4mg/kg/day calcium excretion is abnormal. Advice regarding high fluid intake helps in prevention.

Certain areas are known for increased prevalence for renal calcium or urolithiasis because of hot climate, excess of calcium/ manganese/ aluminium and many other minerals in soil/ water which increase the solute load. People living in these areas including children suffer from increased incidence of stones. In India, Rajasthan, Kutch and certain areas of Gujarat, Punjab are known as stone belts.

What is the

treatment for kidney stones

?

Depending on size, location, whether stone is causing obstruction, stone can be removed by ESWL (Lithotripsy), percutaneous nephrolithotomy (PCNL), cystoscopy (removal of the stone though the bladder with the help of an instrument called as an endoscope) or surgical removal. The modality of treatment depends on expertise of the surgeon and how much the patient can afford.

What is ESWL? Can be done in a child? What are its indications?
ESWL (Extracorporeal shock wave lithotripsy) is a recent advance in treatment of stones. This is done by a special equipment, which is very expensive and is based on bombarding the stone with high frequency shocks. The pulverized stone is than passed in urine as small pieces. More than one
sitting may be needed for removal of single stone. Each sitting costs approximately Rs 5000-6000. In very small infants and children below 5 years of age, it is not advised. Very small (less than 2cm) and very large (more than 8cm) stones can not be treated by ESWL. Calcium oxalate, Struvite and uric acid stones are easy to fragment. Cystine stone are difficult to treat with ESWL.

Does alkalinizing the urine help in dissolving the stone? When should it be done?
Alkali treatment is useful to dissolve crystals before stone formation occurs. Citrate alkali therapy is useful to dissolve uric acid or calcium oxalate crystals, for prevention of recurrence of stones and should be started no sooner the diagnosis is made. Dissolution of a stone may not be possible.

My child had sudden onset of pain, which he felt from the loin to his penis. What to do?
When pain starts suddenly from loin to penis, it means that the stone has moved and is trying to come out. At this time pain reliever and antispasmodic medication is advised namely Ibuprofen and Dicyclomine. Fresh Ultrasonography/ X-rays are needed to localize the stone. Child may require hospitalization if pain is severe till the stone is passed. IV fluids, IV NaHCO3 with furosemide can push the stone out.

Can modification in diet help to decrease formation of renal stones?
Depending on the composition of the stone, diet should be modified e.g. uric acid stones due to high serum uric acid should be treated with restriction of meat, dals and pulses; oxalate stones require restriction of spinach and tomatoes which are rich in oxalates.

In a child with calcium stones, should milk be omitted from the diet?
In growing children, restriction of milk or dairy product to reduce calcium in diet is not advisable because calcium and high class milk proteins are required for growth and mineralisation of bones. Tonics containing excess of calcium should be avoided.

How is a child with renal stones to be monitored?
Child with renal stones should be monitored regularly for symptoms like pain, hematuria, urinary complaints like dysuria (pain while passing urine), frequency, burning etc. Ultrasonography should be done every 2-3 months to look at the progress of stone. Urine is examined for hematuria (blood in urine), pyuria (pus in urine) and if required urine culture for UTI should be done till the stone is passed or removed.

What is the prognosis of a child with renal stones?
Prognosis is good if the stone is single and isolated. But recurrent stones, which obstruct the urinary passage and are associated with recurrent calculi and recurrent UTI can progress to CRF.



Contributor Information and Disclosures

Kumud P Mehta
Consultant Pediatrician & Pediatric Nephrologist, Jaslok Hospital & Research Centre, Bai Jerbai Wadia Hospital for children, Mumbai, India


First Created : 1/3/2001

References

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