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A simple way to reduce catheter-associated UTIs

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The administration of a prophylactic antibiotic when a surgical patient’s urinary catheter is removed can cut the rate of urinary tract infections in half.


 

References

PRACTICE CHANGER

Ensure that antibiotics are administered to surgical patients when their urinary catheter is removed to reduce the risk of urinary tract infections (UTIs).1

Strength of recommendation

B: Based on a meta-analysis.

Marschall J, Carpenter CR, Fowler S, et al; CDC Prevention Epicenters Program. Antibiotic prophylaxis for urinary tract infections after removal of urinary catheter: meta-analysis. BMJ. 2013;346:f3147.

Illustrative case

A 49-year-old man was admitted to the hospital for resection of a vertebral mass. He is almost ready for discharge, and his urinary catheter soon will be removed. Should he be given an antibiotic when his catheter is removed to prevent a UTI?

Approximately 15% to 25% of hospitalized patients receive a urinary catheter, typically during the perioperative period.2 UTIs are the most common hospital-acquired infections, and virtually all of these UTIs are caused by instrumentation of the urinary tract, primarily by catheters.2 Although the mortality rate among patients with catheter-associated UTIs (CAUTIs) is just 2.3%, CAUTIs are the leading cause of hospital-acquired bacteremia, which increases morbidity and length of stay.2 The most common pathogens for CAUTIs are Escherichia coli (21.4%), Candida species (21%), and Enterococcus species (14.9%).2Pseudomonas aeruginosa, Klebsiella, and Enterobacter species make up the bulk of the remainder.2

Support for antibiotic prophylaxis has historically been equivocal

Until now, no data clearly supported routine use of prophylactic antibiotics after urinary catheterization. Centers for Disease Control and Prevention (CDC) guidelines published in 2009 outline which patients are appropriate for catheterization, but do not recommend routine use of antibiotics to prevent CAUTIs.2 The 2014 Infectious Diseases Society of America guidelines, which came out before the study reported on here was published, state the benefit of antibiotics at the time of catheter removal is an unresolved issue.3

STUDY SUMMARY: Meta-analysis shows prophylactic antibiotics reduce UTI ris

Marschall et al1 searched multiple databases for studies published between 1947 and 2012 that evaluated prophylactic use of antibiotics at the time of urinary catheter removal. The endpoint for their analysis was symptomatic UTI, which they defined as bacteriuria plus at least one clinical symptom. Trials were excluded if patients had suprapubic catheters or if antibiotics were started shortly after the catheter was inserted.

The authors analyzed 7 studies. Six were randomized controlled trials, of which one was unpublished. The seventh trial was a nonrandomized study that compared outcomes of patients of 2 surgeons, one of whom used prophylactic antibiotics and one who did not. Five studies enrolled surgical patients exclusively, including 2 that focused on urology patients. In all of the studies, patients had a urinary catheter in place for fewer than 15 days. The duration of antibiotic treatment varied from a single dose to 3 days. The antibiotics used included trimethoprim/sulfamethoxazole, nitrofurantoin, ciprofloxacin, and a cephalosporin.

Antibiotic prophylaxis significantly reduced the rate of CAUTIs. The absolute risk reduction was 5.8%; the rate of CAUTIs was 4.7% in the group treated with antibiotics vs 10.5% in the control group. The number needed to treat to prevent one CAUTI was 17 (95% confidence interval [CI], 12-30), with a risk ratio (RR) of .45 (95% CI, .28-.72). The RR varied only slightly (.36) when the researchers repeated their analysis but excluded the unpublished trial, and remained at .45 when they analyzed only studies of surgical patients.

This meta-analysis suggests that prophylaxis for 3 days or less can reduce the risk of catheter-associated UTIs.The reduction in CAUTIs remained consistent despite varying lengths of antibiotic administration and choice of antimicrobial agents. However, when the authors looked at pooled results just from the 2 studies that included both surgical and medical patients, they found no decrease in CAUTIs.

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