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Catheter-Associated Urinary Tract Infections

By

Talha H. Imam

, MD, University of Riverside School of Medicine

Last full review/revision Jul 2021| Content last modified Jul 2021
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A catheter-associated urinary tract infection (UTI) is a UTI in which the positive culture was taken when an indwelling urinary catheter had been in place for > 2 calendar days. Patients with indwelling bladder catheters are predisposed to bacteriuria and UTIs. Symptoms may be vague or may suggest sepsis. Diagnosis depends on the presence of symptoms. Testing includes urinalysis and culture after the catheter has been removed and a new one inserted. The most effective preventive measures are avoiding unnecessary catheterization and removing catheters as soon as possible.

Bacteria can enter the bladder during insertion of the catheter Bladder Catheterization Bladder catheterization is used to do the following: Obtain urine for examination Measure residual urine volume Relieve urinary retention or incontinence Deliver radiopaque contrast agents or... read more , through the catheter lumen, or from around the outside of the catheter. A biofilm develops around the outside of the catheter and on the uroepithelium. Bacteria enter this biofilm, which protects them from the mechanical flow of urine, host defenses, and antibiotics, making bacterial elimination difficult. Even with thoroughly aseptic catheter insertion and care, the chance of developing significant bacteriuria is 3 to 10% every day the catheter is indwelling. Of patients who develop bacteriuria, 10 to 25% develop symptoms of UTI. Fewer develop sepsis Sepsis and Septic Shock Sepsis is a clinical syndrome of life-threatening organ dysfunction caused by a dysregulated response to infection. In septic shock, there is critical reduction in tissue perfusion; acute failure... read more .

UTIs can also develop in women during the days after a catheter has been removed.

Symptoms and Signs

Patients with catheter-associated urinary tract infection (UTI) can not have some of the symptoms typical of UTIs (dysuria Dysuria Dysuria is painful or uncomfortable urination, typically a sharp, burning sensation. Some disorders cause a painful ache over the bladder or perineum. Dysuria is an extremely common symptom... read more , frequency Urinary Frequency Urinary frequency is the need to urinate many times during the day, at night (nocturia), or both but in normal or less-than-normal volumes. Frequency may be accompanied by a sensation of an... read more ), but they may complain of feeling the need to urinate or of suprapubic discomfort. However, such symptoms of lower tract UTI may also be caused by obstruction of the catheter or development of bladder calculi Urinary Calculi Urinary calculi are solid particles in the urinary system. They may cause pain, nausea, vomiting, hematuria, and, possibly, chills and fever due to secondary infection. Diagnosis is based on... read more . Symptoms of acute or chronic pyelonephritis Acute pyelonephritis Bacterial urinary tract infections (UTIs) can involve the urethra, prostate, bladder, or kidneys. Symptoms may be absent or include urinary frequency, urgency, dysuria, lower abdominal pain... read more may also develop without the typical urinary tract symptoms. Patients may have nonspecific symptoms such as malaise, fever, flank pain, anorexia, altered mental status, and signs of sepsis Sepsis and Septic Shock Sepsis is a clinical syndrome of life-threatening organ dysfunction caused by a dysregulated response to infection. In septic shock, there is critical reduction in tissue perfusion; acute failure... read more .

Diagnosis

  • Urinalysis and urine culture for patients with symptoms or at high risk of sepsis

  • Patients with granulocytopenia

  • Organ transplant patients taking immunosuppressants

  • Pregnant women

  • Patients undergoing urologic surgery

Diagnostic testing includes urinalysis Urinalysis In patients with renal disorders, symptoms and signs may be nonspecific, absent until the disorder is severe, or both. Findings can be local (eg, reflecting kidney inflammation or mass), result... read more Urinalysis and urine culture. If bacteremia is suspected, blood cultures are done. Urine cultures should be done, preferably after replacing the catheter (to avoid culturing colonizing bacteria), then by a direct needlestick of the catheter, all done with aseptic technique, so that contamination of the specimen is minimized.

In women who have had a catheter removed, urine culture within 48 hours is recommended regardless of whether symptoms occur.

Treatment

  • Antibiotics

Asymptomatic, low-risk patients are not treated. Symptomatic and high-risk patients are treated using antibiotics and supportive measures. The catheter should be replaced when treatment begins. Choice of empiric antibiotic is as for acute pyelonephritis Acute pyelonephritis Bacterial urinary tract infections (UTIs) can involve the urethra, prostate, bladder, or kidneys. Symptoms may be absent or include urinary frequency, urgency, dysuria, lower abdominal pain... read more . Sometimes vancomycin is added to the regimen. Subsequently, antibiotics with the narrowest spectrum of activity, based on culture and sensitivity testing, should be used. Optimal duration is not well established but 7 to 14 days is reasonable in patients who had a satisfactory clinical response, including resolution of systemic manifestations.

Asymptomatic women and men with recent catheter removal who have urinary tract infection (UTI) diagnosed by urine culture should be treated based on the culture results. Optimal duration of treatment is not known.

Prevention

The most effective preventive measures are avoiding catheterization and removing catheters as soon as possible. Optimizing aseptic technique and maintaining a closed drainage system also reduce risk. How often and even whether to routinely change indwelling catheters is unknown. Intermittent catheterization carries less risk than use of an indwelling catheter and should be used instead whenever feasible. Antibiotic prophylaxis and antibiotic-coated catheters are no longer recommended for patients who require long-term indwelling catheters.

Key Points

  • Long-term use of indwelling bladder catheters increases risk of bacteriuria, although bacteriuria is usually asymptomatic.

  • Symptomatic UTI may manifest with systemic symptoms (eg, fever, altered mental status, decreased blood pressure) and few or no symptoms typical of UTIs.

  • Do urinalysis and urine culture if patients have symptoms or are at high risk of sepsis (eg, because of immunocompromise).

  • Treat similarly to other complicated UTIs.

  • Whenever possible, avoid use of catheters or remove them at the first opportunity.

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