OBJECTIVE. We report a prospective, randomized, multicenter trial that compared the effect of 3 vs 8 days of intravenous ceftriaxone treatment on the incidence of renal scarring at 6 to 9 months of follow-up in 383 children with a first episode of acute pyelonephritis.
METHODS. After initial treatment with intravenous netilmicin and ceftriaxone, patients were randomly assigned to either 5 days of oral antibiotics (short intravenous treatment) or 5 days of intravenous ceftriaxone (long intravenous treatment). Inclusion criteria were age 3 months to 16 years and first acute pyelonephritis episode, defined by fever of >38.5°C, C-reactive protein level of >20 mg/L, and bacteriuria at >105/mL. All patients underwent 99m technetium-dimercaptosuccinic acid scintigraphy 6 to 9 months after inclusion. A total of 548 children were included, 48 of whom were secondarily excluded and 117 of whom were lost to follow-up or had incomplete data; therefore, 383 children were eligible, 205 of them in the short intravenous treatment group and 178 in the long intravenous treatment group.
RESULTS. At inclusion, median age was 15 months, median duration of fever was 43 hours, and median C-reactive protein level was 122 mg/L. A total of 37% (143 of 383) of patients had a vesicoureteral reflux grades 1 to 3. Patient characteristics at inclusion were similar in both groups, except for a significantly higher proportion of girls in the short intravenous treatment group. The frequency of renal scars at scintigraphy was similar in both groups. Multivariate analysis demonstrated that renal scars were significantly associated with increased renal height at initial ultrasound and with the presence of grade 3 vesicoureteric reflux.
CONCLUSIONS. The incidence of renal scars was similar in patients who received 3 days compared 8 days of intravenous ceftriaxone. Increased renal height at initial ultrasound examination and grade 3 vesicoureteric reflux were significant risk factors for renal scars.