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COMPLICATIONS OF URINARY CATHETERS
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Urinary catheters should be used sparingly. Indwelling urethral catheters are the most common; suprapubic catheters require a surgical procedure but have fewer long-term infectious complications than indwelling urethral catheters after 5 days of use1,2 (see Chapter 92, “Acute Urinary Retention”). Table 95-1 lists the complications of urinary catheters.
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Catheter-associated urinary tract infection (UTI) is one of the most common causes of nosocomial infections.3 The risk of bacteriuria is approximately 3% to 8% per day, with the prevalence reaching almost 100% for long-term catheterization (by 30 days).3 However, bacteriuria does not equate to clinical infection. Infection rates range from 0.5 to 14.8 per 1000 catheter days.4 Comorbidities that increase the risk of infection include female sex, prostatic hypertrophy, elevated creatinine at time of insertion, diabetes, advanced age, catheter care violations, and debilitation.3 Associated microbial factors include the source of the organisms, the specific bacteria, the route of invasion, and the duration of catheterization.
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In the noncatheterized urinary tract, bacteria are efficiently eliminated. Most bacterial strains that are introduced into the catheterized urinary tract, in contrast, are able to multiply to high concentrations in 24 hours. Bacteria may be able to gain access to the urinary tract through the catheter lumen (intraluminal) or along the catheter surface (extraluminal). If the drainage tube lumen is colonized, bacteria may ascend the collection bag and catheter and may cause an infection. An infection from the catheter lumen route begins with the formation of a biofilm on the catheter’s inner surface. This biofilm extends from the uroepithelium through catheters to the drainage bag and allows adherence of bacteria to a catheter or mucosal surface. Organisms become embedded within the biofilm and gain protection from the mechanical flow of urine, host defenses, and antibiotics.5 The microbiology varies according to the duration of catheter placement. During short-term catheterization, infections are usually due to single organisms, most commonly Escherichia coli, followed by Klebsiella, Pseudomonas, Enterobacter, and gram-positive cocci such as staphylococci. With long-term catheterization (≤30 days), catheter-associated UTIs are usually polymicrobial from E. coli, Proteus mirabilis, Pseudomonas, Morganella morganii, and Candida species.
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Signs and symptoms include fever, rigors, altered mental status, malaise, or lethargy ...