Calcium-creatinine ratio in a morning urine sample for the estimation of hypercalciuria associated with non-glomerular hematuria observed in children and adolescents

Background

Hypercalciuria might be revealed during the differential diagnosis of hematuria accompanying renal lithiasis (RL). In spite of this, diagnostic accuracy of calcium urinary excretion might be affected by incomplete 24-hour urine collections. In the present study, the diagnostic utility of calcium/creatinine (ICaCre) index for determining hypercalciuria associated with non-glomerular hematuria (NGH) and RL was assessed.

Method

ICaCre (mg/mg) index was calculated from calcium (mmol/l) and creatinine (µmol/l) concentrations in an aliquot from a 24-hour urine collection in 169 children and adolescents with NGH or RL. Calciuria values > 4.0 mg/kg in 24 hours were distributed according to the presence of NGH or RL.

Results

Mean ICaCre index was 0.2 ± 0.1 mg/mg. Calciuria values estimated from ICaCre were statistically higher to those from 24-hour urine collection (p < 0.05). The frequency of hypercalciuria was independent from the measurement method (estimated from ICaCre 39.5% vs. 24 h collection 32.1%; p > 0.05). Hypercalciuria distribution was as follows: no NGH + no RL: 59.0%; no NGH + RL: 60.0% (∆ = +1.0%); NGH + no RL: 68.2% (∆ = +9.2%); NGH + RL: 73.3% (∆ = +14.4%).

Conclusions

The use of ICaCre index for determining calcium urine excretion might be effective in the study of hypercalciuria associated with NGH and RL.

Review on renal recovery after anatrophic nephrolithotomy: Are we really healing our patients?

The main goals for urinary stone treatment are to preserve renal function, reduce or avoid complications related to calculi, and to render the patient free of calculi as soon as possible. Anatrophic nephrolithotomy (ANL) is a valid and useful alternative for conventional staghorn calculi excision. Although excellent stone free rates can be achieved with ANL there are some drawbacks that may be of concern. Morbidity related to intraoperative and postoperative complications is one of them. Another, great concern is the possibility of reduction on renal function related to the procedure itself. This may be related to nephron injury during nephrotomy and parenchymal closure or to ischemic injury. In this review we assess functional results after anatrophic nephrolithotomy.