Cath Lab Digest

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  Urinary tract infections (UTIs) are the most prevalent infection in long-term care (LTC), accounting for at least 40% of all infections and more than 8% of total nursing home costs.^1,2 UTIs are the most prevalent source of bacteremia, the most common cause for hospital transfers, and the most common condition for which antibiotics are prescribed. Although patients usually respond to antimicrobial treatment, the recurrence rate is high and associated with side effects. It is estimated that more than 50% of elderly patients in LTC will have a recurrence, usually within 6 months, despite antibiotic therapy.^3,4 The frustration of repeated cycles of antibiotic agents with diminished effects due to microbial resistance has a significant impact on the patient’s quality of life (QoL).

Antibiotic Usage

  UTIs alone account for 30% to 56% of all prescriptions for antibiotics in LTC facilities.^5,6 Escherichia coli is the most common cause of UTIs in older adults. E. coli strain resistance is now approximately 40% to 50% to ampicillin, approximately 20% to trimethoprim-sulfamethoxazole, and in just the last few years resistance has gone from 1% to 5% to more than 20% to fluoroquinolone.⁷ This reduces treatment options for UTIs and can add significant costs when newer, more expensive antibiotics are needed. Additionally, every antibiotic regimen fosters resistant subpopulations of bacteria that can later re-infect that same patient or their caregivers or be passed around to other patients, particularly in the LTC environment. Side effects of antibiotics also must be considered and include allergic reactions, nausea, interactions with foods or other drugs, and depletion of beneficial bacteria in the colon that can lead to diarrhea, stomach or intestinal upset, changes in mental status, yeast infections, and Clostridium difficile (C. diff).

Development of UTIs

  Urine is normally sterile, so in order for a UTI to occur, E. coli from a fecal or vaginal source must migrate upward, enter the urethra, attach, and begin to multiply. As the bacteria multiply, they ascend up the urethra into the bladder. E. coli have finger-like projections (fimbriae) on their cell surface that allow them to attach to receptors on epithelial cell walls using a Velcro-like effect that can resist the cleansing action of urine flow. Because E. coli are living, they continue to move after adherence, irritating and destroying the urethral or bladder wall and causing inflammation. The inflammation causes a painful burning sensation. In some cases, these pathogens will rupture underlying blood vessels, resulting in visible blood in the urine. Inhibiting E. coli from attaching to the urinary tract wall is one of the most important ways to prevent UTIs.

  Older adults are at increased risk for UTIs due to age-related changes. Decreased estrogen as part of menopause leads to thinning and weakening of the mucosa, reducing its ability to resist bacteria. A decrease in estrogen also leads to pH changes in the vagina, favoring E. coli colonization. An aging immune system decreases antibody response to pathogens. Changes in microbiota (microflora) include an increase in harmful bacteria and a decrease in beneficial bacteria. Plus, as we age, the ability to concentrate urine decreases. To help counteract these changes, daily consumption of cranberry products is recommended.

Cranberries

  Proanthocyanidins (PACs) — flavonoids found in cranberries — can prevent E. coli from attaching to the urinary tract wall.