Uric Acid Stones Follow-up
- Author: Sahar Fathallah-Shaykh, MD; Chief Editor: Craig B Langman, MD more...
Further Inpatient Care
- Inpatient care is indicated for management of renal failure, urologic surgery, severe pain, infection, or obstruction.
Further Outpatient Care
The child should continue a low-purine diet if prescribed.
- Continue Bicitra (2-6 mEq/kg/d) for urinary alkalinization.
- Parents can be provided urine dipsticks to monitor urine pH level and specific gravity to assess the adequacy of treatment. Urine pH levels should be maintained above 7. Urine specific gravity should be maintained below 1.01.
- Fluid intake should be sufficient to maintain urine output of 30 mL/kg/24h or more.
- Allopurinol is continued to lower uric acid production if prescribed.
Children with urinary tract uric acid stones and/or urinary tract anatomic abnormalities or a previous urinary tract infection may require urinary tract infection uroprophylaxis.
Inpatient & Outpatient Medications
- A low-purine diet, allopurinol, Bicitra, and aggressive hydration should be continued. The goals are to dissolve present stones and to prevent new stones.
Deterrence/Prevention
- A low-purine diet, urinary alkalinization, and large fluid intake may prevent new stones from forming.
Complications
Complications of renal stone disease include the following:
- Bleeding
- Obstruction
- Infection
- Pain
- Complications of acute renal failure (ie, hypertension, hyperkalemia, pulmonary edema)
Prognosis
- The prognosis depends on the primary disease process. Children with cancer and Lesch-Nyhan syndrome tend to do worse than children with isolated HGPRT defects.
Patient Education
- Inform patients about the specific disease process when possible.
- Discuss the importance of diet, medication, and fluid intake in preventing new stone formation.
- Indicate the importance of physician reevaluation if the child develops fever, pain, vomiting, dehydration, renal colic, or gross hematuria.
- For excellent patient education resources, visit eMedicine's Kidneys and Urinary System Center. Also, see eMedicine's patient education article Kidney Stones.
Baldree LA, Stapleton FB. Uric acid metabolism in children. Pediatr Clin North Am. Apr 1990;37(2):391-418. [Medline].
Fujita T, Shimooka T, Teraoka Y, Sugita Y, Kaito H, Iijima K, et al. Acute renal failure due to obstructive uric acid stones associated with acute gastroenteritis. Pediatr Nephrol. Dec 2009;24(12):2467-9. [Medline].
Kaneko K, Shimo T, Hirabayashi M, Ito T, Okazaki H, Harada Y. Cause of uric acid stones in rotavirus-associated gastroenteritis. Pediatr Nephrol. Oct 2010;25(10):2187-8. [Medline].
Kato K, Sai S, Hirata T, et al. Two cases of ammonium acid urate urinary stones related to anorexia nervosa and laxative abuse. Hinyokika Kiyo.Mar. 2004;50(3):181-5. [Medline].
Sakhaee K, Maalouf NM. Metabolic syndrome and uric acid nephrolithiasis. Semin Nephrol. Mar 2008;28(2):174-80. [Medline].
Raj GV, Auge BK, Assimos D, Preminger GM. Metabolic abnormalities associated with renal calculi in patients with horseshoe kidneys. J Endourol. Mar 2004;18(2):157-61. [Medline].
Barrat TM, PG Duffy. Nephrocalcinosis and Urolithiasis. In: Pediatric Nephrology. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 1999:933-46.
Camron JS, F Moro. Gout, Uric Acid, and Purine Metabolism in Pediatric Nephrology. In: Pediatric Nephrology. Vol 7. 1993:105-18.
Johnson RJ, Kivlighn SD, Kim YG, et al. Reappraisal of the pathogenesis and consequences of hyperuricemia in hypertension, cardiovascular disease, and renal disease. Am J Kidney Dis. Feb 1999;33(2):225-34. [Medline].
| Neonates* | Children | Adults | |||||||||
| 29-33 wk | 34-37 wk | 38-40 wk | 3-4 y | 5-9 y | 10-14 y | 40-44 y | |||||
| Male | Female | Male | Female | Male | Female | Male | Female | ||||
| Serum uric acid (mg/dL) | 7.71±2.65 | 6.04±2.19 | 5.19±1.57 | 3.45±1.01 | 3.44±0.8 | 3.63±1.04 | 3.71±0.92 | 4.28±1.19 | 4.09±1.2 | 5.134±1.25 | 4.25±1.1 |
| Uric acid excretion (mg/dL GFR†) | 4.8±2.23 | 2.81±0.93 | 1.69±0.84 | 0.34±0.11 | 0.403±0.095 | ||||||
| Uric acid excretion (mg/kg/d) | N/A | N/A | 19.6 | 13.5±3.75 (3 y) | 11.5±3.75 (7 y) | 9±3.75 (12 y) | 10 | ||||
| Fractional excretion of uric acid (%) | 61.24±12.21 | 44.52±15.23 | 38.19±13.61 | 12±3.75 (3 y) | 10±3 (7 y) | 7.6±3.75 (12 y) | 7±1.6 | ||||
| *Gestational ages † Glomerular filtration rate | |||||||||||

