Assessment of recoverability of kidney function in children with obstructive calcular anuria: multicenter study

Urolithiasis in children can cause considerable morbidity. Our aim was to evaluate the impact of intervention on the recoverability of kidney functions.

This prospective study included 93 children (66 boys and 27 girls) with median age of 3 years (range 0-14). Inclusion criteria were presence of anuria, oliguria, serum creatinine >2 mg% and/or hyperkalemia ≥ 6 mmol/L. The mean duration of anuria or oliguria was (mean ± SE) 5.3 ± 0.4 days. On presentation, mean plasma creatinine was 6.5 ± 0.29 mg/dl with a mean estimated glomerular filtration rate (eGFR) of 14 ml/min and creatinine clearance (CC) of 8.24 ml/min. Dialysis was performed in 21 (22.6%) patients. When condition allowed, emergency surgery was performed.

Mean follow up was 1.5 years with compliance of 82%. At the end of treatment, 83% of patients had complete clearance of calculi. Mean plasma creatinine after treatment was 3.3 ± 0.35 mg/dl with an average GFR of 24.5 ml/min. After treatment renal function returned to normal in 57%, improved in 27% and deteriorated in 16% of children. Renal function recoverability rate was 94.6%. Chronic renal failure developed in 3 (3.2%) patients and 2 (2.2%) patients died. When absolute plasma creatinine concentration [P(cr)] improved 20-50% the eGFR and CC were doubled, and when improved 50-70% eGFR and CC tripled. Beyond 70% improvement in [P(cr)], eGFR and CC improved 7-8 times. Using Spearman's correlation, the mode of presentation and the type of management had a significant correlation with renal function outcome (P = 0.019 and 0.013 respectively).

Urgent management of calcular anuria both medically and surgically is the cornerstone for favorable outcome. The mode of presentation and the type of management are significant factors affecting final renal function outcome.