Solitary kidney.

The study provides the pediatric practitioner with a tool to determine whether the child with an apparently normal solitary kidney requires an in-depth investigation. Medical records from January 1, 1995 to December 31, 2006 identified 96 children with solitary kidneys and showed 78 with a normal appearing, hypertrophied solitary kidney. Study groups included (1) children 1 to 2 years, (2) girls older than 2 years and boys 2 to 13 years, and (3) boys older than 13 years. Serum creatinine concentrations and estimated glomerular filtration rate were calculated for each group. The mean serum creatinine concentrations in group 1 was 0.4+/-0.1 mg/dL, group 2 was 0.6+/-0.2 mg/dL, and group 3 was 1.1+/-0.2 mg/dL. An estimated glomerular filtration rate 2 SD below the mean suggests further investigation. An estimated glomerular filtration rate 2 SD below the mean was 78 mL/min/1.73 m(2) in group 1, 73 mL/min/1.73 m(2) in group 2, and 70 mL/min/1.73 m(2) in group 3.