In its 1999 practice parameter on the diagnosis, treatment, and evaluation of urinary tract infections in children, the AAP recommended that all children who are suspected of having their first urinary tract infection have a renal ultrasound and voiding cystourethrogram.
Ron Keren, MD, MPH, director of the Center for Pediatric Clinical Effectiveness at Childrens Hospital of Philadelphia, spoke about this topic at the annual meeting of the AAP in Boston and said this recommendation is controversial.
The recommendations are actually written for children who are aged 2 to 24 months, said Keren. If you look at the epidemiology of UTIs, the majority of children are aged between 2 and 6 years when they get their first UTI. Additionally, they give recommendations for imaging, but then they dont tell you what to do with the findings that you uncover on the imaging studies.
Keren said that four well-designed studies evaluate whether it makes sense to perform a renal ultrasound on every child with a UTI. The proportion of ultrasounds with abnormal findings and the types of abnormalities were consistent across the four studies. However, the proportion of abnormalities deemed clinically significant varied widely across studies, depending on the authors opinions about whether the findings required a change in management.
Renal ultrasound is a relatively inexpensive, noninvasive test that is currently recommended by the AAP after a first UTI, said Keren. However, if you want to be parsimonious about whom you choose to screen by renal ultrasound, these are some of the factors that could increase the risk of finding some abnormality on the ultrasound: a complicated UTI that didnt get better in 48 hours, a child with recurrent UTIs, a child with reflux and being male.
Treating vesicoureteral reflux
Cystourethrography is helpful in identifying those patients who have vesicoureteral reflux. Keren noted the American Urologic Association recommends considering the age of the child, the grade of the vesicoureteral reflux and whether or not there is scarring present at the time of diagnosis when deciding treatment management for these patients. Most of us are dealing with a situation where we have a child who is coming in for the first time with a UTI. We dont know about scarring so we assume that they dont have any. Except for children aged between 1 and 5 years and have bilateral grade 5 vesicoureteral reflux, the AUA recommends that all other children receive prophylactic antibiotics, Keren said.
Todays use of prophylactic antibiotics as the first-line treatment for children with vesicoureteral reflux is a big shift from the 1970s and 80s, where surgery was often considered first-line therapy, Keren said.
Keren reviewed the results of observational studies and clinical trials that evaluated the risks and benefits of antibiotic prophylaxis. Clinical trials performed in the last three years have shown no decreased rate of recurrent UTIs with antibiotic prophylaxis, but all of these trials had serious methodological limitations, like being unblinded, only studying children with low-grade VUR, using bag urine specimens to diagnose UTIs, and being underpowered to show clinically significant differences in recurrent UTI rates, Keren said.
Keren also described the Randomized Intervention for children with Vesicoureteral Reflux (RIVUR) study, a randomized placebo controlled trial of prophylactic TMP-SMZ for children diagnosed with vesicoureteral reflux after a first or second UTI. This NIH-sponsored trial taking place at 19 medical centers across North America addresses the methodological limitations of previous trials, and will tell us whether prophylactic antibiotics are beneficial for all children with VUR, or perhaps just a subset of them. Keren said.
Until the RIVUR study is completed, what are the options? If you are fairly conservative and you want to practice according to what the most recent recommendations are, I would say just maintain the status quo. Absence of evidence is not evidence of absence of benefit. If you feel more comfortable with individualized care, I think thats reasonable, too, he concluded. – by Michelle Stephenson
For more information:
- Keren R. Antibiotic prophylaxis for the urinary tract: pros and cons. Presented at: the Annual Meeting of the American Academy of Pediatrics. Oct. 11-14, 2008; Boston.