Am Fam Physician. 2006;74(2):329-330
Vesicoureteral reflux (VUR) is associated with urinary tract infections (UTI) in children and often is assumed to predispose them to recurrent urinary infections, pyelonephritis, and renal scarring. Prophylactic antibiotics or surgery is commonly recommended for UTIs with VUR to prevent long-term damage; however, it is not known whether any treatment is really helpful. Garin and colleagues wanted to determine if patients with an episode of acute pyelonephritis were more likely to have frequent or severe UTIs and renal damage in the presence of VUR. They also reviewed whether antibiotic prophylaxis was successful in preventing these sequelae in patients with VUR.
Patients three months to 18 years of age with an episode of acute pyelonephritis were enrolled in the study, but those with severe VUR were excluded. Participants with and without mild to moderate VUR, which was diagnosed by a voiding cystourethrogram, were randomized to receive long-term prophylactic antibiotics or not receive prophylaxis. The researchers repeated baseline voiding cystourethrography and renal ultrasonography at the end of one year in the 218 patients who completed the study. Additionally, a dimercaptosuccinic acid renal scan was performed at six months after the original episode of pyelonephritis; whenever a patient had a febrile UTI; or six months after any additional episode of pyelonephritis.
Patients received routine interval examinations with urinalysis and culture every three months or whenever they experienced any symptoms of UTI. Although baseline characteristics were similar among the groups, the prophylaxis group was smaller because of drop-out rates, which was attributed to compliance issues with the antibiotic therapy.
Recurrent UTI was categorized as cystitis, pyelonephritis, or asymptomatic. Overall, recurrence in participants receiving no prophylaxis occurred in 22.4 percent of those with VUR and in 23.3 percent of those without VUR. For individuals receiving prophylaxis, recurrence was 8.8 percent in patients without VUR and 23.6 percent in those with VUR. However, the difference between the two rates was not significant.
Using prophylactic antibiotics did not prevent recurrent pyelonephritis; more patients in this group had pyelonephritis. Moreover, all bacteria involved in the prophylactic group showed resistance to the antibiotic used.
Thirteen patients developed renal scarring, including seven from the VUR group (6.2 percent) and six (5.7 percent) from the group without VUR. Of the patients with VUR, 9.0 percent on prophylaxis developed renal scarring compared with 3.4 percent not on prophylaxis. In participants without VUR, 4.5 percent on prophylaxis developed scarring compared with 6.6 percent not on prophylaxis. These differences were not statistically significant.
This study is the first randomized controlled trial to evaluate the effect of antibiotic prophylaxis on UTI recurrence rates and renal scarring in patients with pyelonephritis. It found that antibiotic prophylaxis use versus nonuse results in similar recurrence rates and parenchymal scarring regardless of whether patients have VUR or not. The authors caution that observedP values indicating lack of statistically significant differences may be related to the relatively small study size, and that larger studies are needed to corroborate these findings.
EDITOR'S NOTE: Regarding the evaluation of children with first UTI, the American Academy of Pediatrics Clinical Practice Guidelines, published in 1999, state that surgical procedures or antibiotic therapy may prevent renal damage in children with VUR who are at risk of renal failure and hypertension.1 Because this study questions the assumptions that VUR is a causal step in the progression to renal scarring and that patients with first febrile UTI should receive antibiotic prophylaxis, its findings limit the usefulness of ultrasound cystourethrography or radionuclide cystography (used to detect VUR and renal scarring, respectively).—c.w.
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