Catheter Replacement Before Antimicrobial Therapy for Symptomatic UTI

Abstract & Commentary

Synopsis: This study suggests a simple intervention: changing the indwelling urinary catheter can improve clinical and bacteriological outcomes both during and after therapy by about 50%.

Source: Raz R, et al. J Urol 2000;164:1254-1258.

Chronic indwelling urinary catheters are frequently associated with urinary tract infections (UTIs). The inner surface of the catheter becomes coated with a dense bacterial biofilm. Organisms may become embedded in this biofilm and survive due to decreased diffusion of antimicrobials into it. This explains why bacterial counts are higher in urine specimens aspirated from a chronic in situ catheter compared with a specimen obtained after catheter replacement. While routine catheter replacement in non-infected individuals does not lead to better outcomes, would catheter replacement prior to instituting antibiotic therapy for UTI result in improved outcomes in patients with chronic indwelling catheters in long-term care facilities? Raz and colleagues conducted a pro-spective, randomized, open clinical trial at two long-term care facilities to answer the question.

Fifty-four nursing home residents, 21 male and 33 female, mean age 72.6 years with a clinical diagnosis of UTI were enrolled in the study. Those with gross hematuria or obstruction were excluded from the study. Twenty-seven cases were randomized to either catheter replacement or no replacement before antibiotics were begun. Ciprofloxacin or ofloxacin was used and treatment was continued for 14 days. Clinical and bacteriological outcomes were assessed after three days of therapy, and then seven and 28 days after therapy completion.

The two groups, catheter replacement and no replacement, had similar characteristics. There were similar numbers of diabetics in both groups, and the presenting features, including fever, leucocytosis, bacteremia, and the organisms cultured were also similar. Catheter replacement was associated with a shorter duration of fever, 2.9 ± 1.9 days compared with 4.6 ± 1.9 days (P = 0.05) for those without catheter replacement. Catheter replacement was also associated with improved clinical and bacteriological outcomes during and post-therapy (see Table). The relapse rate 28 days post-therapy was only 11% in those with catheter replacement compared with 41% in those without replacement (P = 0.015). There were only two deaths and both were inpatients without catheter replacement.

Table. Catheter Replacement in UTI: Clinical and Bacteriological Outcomes
During Rx  Day 3 Post Rx Day 7 Post Rx Day 28
No growth on urine culture (%) 89% 30% P<0.001 67% 33% P=0.01 48% 19% P=0.02
Clinical cure or improvement (%) 93% 41% P<0.001 93% 78% 89% 54%
Clinical relapse rate (%) 7% 29% 11% 41% P=0.015
catheter replacement (REP)
no catheter replacement (NO REP)

Comment by Kamaljit Sethi, MD, FACP

Up to 10% of elderly long-term care individuals have chronic indwelling urinary catheters. Polymicrobial bacteriuria and serious invasive UTIs are serious complications and contribute to both morbidity and mortality. While it is accepted that asymptomatic bacteriuria should not be treated, clearly symptomatic UTI with and without bacteremia merits therapy. This study suggests a simple intervention: changing the indwelling urinary catheter can improve clinical and bacteriological outcomes both during and after therapy by about 50%. This means better, faster, and less expensive care for a common clinical problem. It makes sense to consider that removal of the catheter and hence, adherent biofilm in symptomatic UTI, would lead to improved outcomes.