Delayed Therapeutic Response Time Predicts Renal Damage in the First Episode of Febrile Urinary Tract Infection.

Objective: To evaluate the relationship of therapeutic delay time (TDT) and therapeutic response time (TRT) with renal damage in the first episode of febrile urinary tract infection (UTI). Material and Method: A prospective study was conducted in 67 children with the first episode of UTI at the Department of Pediatrics, Faculty of Medicine Siriraj Hospital between 2008 and 2010. To assess for renal damage, dimercaptosuccinic acid (DMSA) renal scintigraphy was performed at one and six months after the acute episode. Results: Abnormal DMSA renal scintigraphy was detected in 20 (29.9%) patients. There was no difference in TDT but TRT was different between the patients with normal and abnormal DMSA renal scintigraphy at p-value 0.001. The area under receiver operating characteristic (ROC) curve for TRT was 0.76 (95% confidence interval (CI) 0.64-0.86) at p-value 0.001. The optimal cut-off value for TRT was 22 hours with sensitivity 80.0% (56.3-94.1) and specificity 63.6% (47.8-77.6). In 50 patients with no vesicoureteral reflux (VUR), there was difference in TRT at p-value 0.002. The area under ROC curve for TRT was 0.82 (95% CI 0.69-0.96) at p-value 0.004. The optimal cut-off value for TRT was 25 hours with sensitivity 88.9% (95% CI 51.7-98.2) and specificity 68.4% (95% CI 51.3- 82.5). Conclusion: TRT at or more than 22 hours predicts renal damage after first episode of UTI. In patients with no VUR, TRT at or more than 25 hours predicts renal damage. DMSA renal scintigraphy in the first episode of UTI should be considered in these patients.

The role of DMSA renal scintigraphy in the first episode of urinary tract infection in childhood.

OBJECTIVE: The role of dimercaptosuccinic acid (DMSA) renal scintigraphy in the first episode of urinary tract infection (UTI) has been the subject of debate for many years. The aim of this study was to evaluate the relationship of voiding cystourethrography (VCUG), renal ultrasonography and DMSA renal scintigraphy and to detect renal parenchymal changes by performing DMSA renal scintigraphy at 6 months after the first episode of UTI. METHODS: A prospective study was conducted in 67 hospitalized children (46 boys, 21 girls). Mean age of the patients was 0.97 ± 1.57 years (0.02-7.26 years). All children received VCUG, renal ultrasonography and DMSA renal scintigraphy. DMSA renal scintigraphy was performed at 1 and 6 months after UTI. RESULTS: Of 67 children, 17 (25.4%), 23 (34.3%) and 20 (29.9%) had vesicoureteral reflux (VUR), abnormal renal ultrasonography and abnormal DMSA renal scintigraphy, respectively. Unilateral hydronephrosis had a significant correlation with VUR at p value 0.024. In renal units, abnormal renal ultrasonography and hydronephrosis had significant correlations with VUR at p values 0.039 and 0.021, respectively. In patients and renal units, hydronephrosis had no significant correlation with abnormal DMSA renal scintigraphy at 1 month after UTI. However, abnormal renal ultrasonography and VUR had significant correlations with abnormal DMSA renal scintigraphy at p values 0.022 and < 0.001 in patients and at p values 0.024 and < 0.001 in renal units, respectively. Both in patients and renal units, VUR (Grade I-III) had no significant correlation with abnormal DMSA renal scintigraphy. However, severe VUR (Grade IV-V) had significant correlations with abnormal DMSA renal scintigraphy at p values < 0.001 and < 0.001, respectively. Seventeen patients underwent DMSA renal scintigraphy at 6 months after UTI. In addition, 15 (88.2%) developed persistent renal scarring. CONCLUSION: Abnormal renal ultrasonography and severe VUR identify renal parenchymal changes. DMSA renal scintigraphy in the first episode of UTI should be carried out in those patients. Abnormal DMSA renal scintigraphy at 1 month after UTI has a tendency to persist.