Predictors of abnormal renal cortical scintigraphy in children with first urinary tract infection: the importance of time factor.

Introduction: We evaluated different factors predicting the development of acute pyelonephritis in Iranian children, with special attention to time factor.

Methods: One hundred nineteen patients (93 females and 26 males; age = 32.6 ± 30.8 months) with first urinary tract infection (UTI) were evaluated. None had previous urological problems. Prior to antibiotic therapy blood samples were gathered for laboratory evaluation. Vital signs on admission were measured. Clinical and laboratory indices, including therapeutic delay time (TDT) and therapeutic response time (TRT), were measured. Most patients were evaluated with renal ultrasound in the first three days following admission. All patients underwent dimercaptosuccinic acid (DMSA) renal scintigraphy and 71 were assessed for vesicoureteral reflux (VUR).

Results: DMSA scans were abnormal in 77 cases, of which 11 cases had bilateral renal involvement. Mean values for TDT, TRT, leukocyte count (LC), absolute neutrophil count (ANC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) were 74.1 h, 39.6 h, 15725 ± 6682 mm(-3), 10772 ± 6458 mm(-3), 51.9 ± 32.5 mm, and 27.3 ± 25.1 mg l(-1), respectively. VUR was present in 29 of 142 evaluated renal units.

Conclusion: TDT ≥ 48 h, TRT ≥ 24 h, axillary temperature ≥ 39°C, LC ≥ 13500 mm(-3), and age ≥ 18 months predicted abnormal DMSA scan in patients with first episode of UTI. Considerably higher TDT and TRT values of the current study compared to previous ones suggests the more important role of time factor in predicting abnormal DMSA findings in a developing country than in developed ones.