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Reference: BMJ 2013 Jun 11;346:f3147, (level 2 [mid-level] evidence)
Urinary tract infections (UTIs) are among the most common hospital-acquired infections, and a large proportion of which are associated with urinary catheters. Currently, the Infectious Disease Society of America (IDSA) recommends against prophylaxis at the time of catheter removal due to concern about selecting for antimicrobial resistance (Clin Infect Dis. 2010 Mar 1;50(5):625-63). A recent systematic review of 6 randomized trials and 1 prospective cohort study compared the efficacy of antibiotic prophylaxis to placebo or no treatment for prevention of symptomatic UTI following short-term urinary catheterization (duration ≤ 14 days) in 1,520 predominantly post-surgical patients.
Antibiotics used included ciprofloxacin ranging from single dose to 3 days of therapy (in 3 trials and cohort study), trimethoprim-sulfamethoxazole ranging from single dose to 10 days of therapy (in 2 trials) and nitrofurantoin (2 doses in 1 trial). Median duration of catheterization ranged from 1.9 to 11 days in prophylaxis groups and from 1.8 to 33 days in control groups. Follow-up ranged from 4 days to 6 weeks. In analysis of all studies, antibiotic prophylaxis was associated with reduced risk of symptomatic UTIs (risk ratio 0.45, 95% CI 0.28-0.72), with a number needed to treat (NNT) of 14-34, assuming a 10.5% rate of UTIs in controls. Only 2 of the 7 trials included medical patients and the total number of medical patients included in the meta-analysis was only 76 (5%). Sub-analyses of the 5 studies of only surgical patients found similar relative risks as the entire analysis, but there was no sub-analysis that included only medical patients.
Although this meta-analysis demonstrated a significant decrease in symptomatic UTI, there are a number of concerns that limit the generalizability of the findings. There was significant heterogeneity of the patient populations (some trials restricted to genito-urinary surgery patients and others excluding them), duration of catheter use, duration of follow-up, and selection of antibiotic. Present recommendations to reduce catheter-associated urinary tract infections focus on appropriate catheter use, insertion technique and early removal. Such measures were not clearly implemented in all trials, which dated back to 1984. Finally, it is not clear that treating everyone to prevent a UTI is a superior strategy to treating the much smaller number of patients who actually get a UTI. Additional studies are needed to identify which specific populations might benefit from routine prophylaxis.
For more information, see the Catheter-associated urinary tract infection (CAUTI) topic in DynaMed.