Metabolic Evaluation in Pediatric Urolithiasis: Our Experience

Pediatric urolithiasis is a morbid condition that is often associated with underlying metabolic disorders. It is essential to diagnose and manage the underlying metabolic disorder along with management of urolithiasis to prevent stone recurrence and decrease the morbidity. Materials and Methods: This retrospective observational study was conducted in 50 patients below 15 years of age with urolithiasis. Urine collection was done for 24 hours in toilet-trained children and spot samples were taken from younger children. The urinary parameters that were evaluated included calcium, oxalate, citrate, uric acid, and total urine volume. The serum levels of calcium, phosphorus, creatinine, uric acid, electrolytes, parathormone, and albumin were also measured. Stone analysis was done whenever possible. Results: There were 32 males and 18 females. Sixty-two percent of the patients had a low calcium intake and 70% of the children had a history of low water intake and had a low urine volume over 24 hours. Half of the children had serum metabolic abnormalities, including hypocalcaemia (n=19,38%), hypocalcaemia with hyperphosphatemia (n=2, 4%), hypercalcemia (n=2, 4%), and hyperuricemia (n=2,4%). Urinary abnormalities were detected in 42% of the children (n=21). These abnormalities included hypocitraturia in 11 patients (50%), hypercalciuria in 7 patients (30%), hyperoxaluria in 1 patient (6%), and hyperuricosuria in 2 patients (12%). Stone analysis was done in 18 patients. Fifteen patients (30%) had calcium oxalate stones, two patients (4%) had uric acid stones, and one patient had a mixed stone. Conclusions: It is important to maintain an optimal blood calcium level and increase fluid intake to prevent stone formation in children.