New strategies to prevent catheter-associated urinary tract infections

Catheter-associated urinary tract infection (CAUTI) is the most common health-care-associated infection worldwide. Although not all cases of bacteriuria result in clinical infection, several hundred thousand episodes of CAUTI occur each year in the USA alone. The milieu in which the catheter is placed is highly conducive to bacterial colonization, biofilm formation on the catheter surface, and inevitable catheter-associated bacteriuria. A multitude of novel methods of CAUTI prevention have been described, including established approaches that are routinely recommended, such as the use of a secured, closed, silicone urinary catheter drainage system that mimics normal voiding, and newer strategies focusing on biocompatible catheter materials that cause minimal host inflammatory response and retard biofilm formation. Much recent research has focused on modification of the catheter surface by either coating or impregnation with antimicrobials or antiseptics. However, clinical trials that analyse cost-effectiveness and rates of antimicrobial resistance are awaited. More recently, innovative use of iontophoresis, vibroacoustic stimulation, bacterial interference and bacteriophage cocktails has been reported.     

Role of biofilm in catheter-associated urinary tract infection

The predominant form of life for the majority of microorganisms in any hydrated biologic system is a cooperative community termed a "biofilm." A biofilm on an indwelling urinary catheter consists of adherent microorganisms, their extracellular products, and host components deposited on the catheter. The biofilm mode of life conveys a survival advantage to the microorganisms associated with it and, thus, biofilm on urinary catheters results in persistent infections that are resistant to antimicrobial therapy. Because chronic catheterization leads almost inevitably to bacteriuria, routine treatment of asymptomatic bacteriuria in persons who are catheterized is not recommended. When symptoms of a urinary tract infection develop in a person who is catheterized, changing the catheter before collecting urine improves the accuracy of urine culture results. Changing the catheter may also improve the response to antibiotic therapy by removing the biofilm that probably contains the infecting organisms and that can serve as a nidus for reinfection. Currently, no proven effective strategies exist for prevention of catheter-associated urinary tract infection in persons who are chronically catheterized.     

Catheter-associated infections: pathogenesis affects prevention

Intravascular catheters and urinary catheters are the 2 most commonly inserted medical devices in the United States, and they are likewise the two most common causes of nosocomially acquired bloodstream infection. Biofilm formation on the surfaces of indwelling catheters is central to the pathogenesis of infection of both types of catheters. The cornerstone to any preventive strategy of intravascular catheter infections is strict attention to infection control practices. Antimicrobial-impregnated intravascular catheters are a useful adjunction to infection control measures. Prevention of urinary catheter-associated infection is hindered by the numbers and types of organisms present in the periurethral area as well as by the typically longer duration of catheter placement. Antimicrobial agents in general have not been effective in preventing catheter-associated urinary tract infection in persons with long-term, indwelling urethral catheters. Preventive strategies that avoid the use of antimicrobial agents may be necessary in this population.     

Indwelling catheter management: from habit-based to evidence-based practice

Indwelling urinary catheters are used in the care of more than five million patients per year. Prevalence rates range from 4% in home care to 25% in acute care. Catheter-associated urinary tract infections account for more than 40% of all nosocomial infections and can be associated with significant complications. Clinical practices in catheter management vary widely and frequently are not evidence-based. Effective nursing measures include: identifying patients who no longer need indwelling catheters, discussing appropriate catheter alternatives, and providing patient and caregiver education. Many catheter-associated problems can be avoided by selecting a closed catheter system with a small size catheter (14 to 18 French with a 5-cc balloon), following manufacturer's recommendations for inflation/deflation, maintaining a closed system, securing the catheter, and properly positioning the drainage bag. Practices such as routine catheter irrigation should be avoided. Current recommendations related to the management of encrustation and blockage also are discussed. Providing evidence-based catheter management strategies may reduce the rate of catheter-associated urinary tract infection, catheter encrustation, and leakage as well as the discomfort and costs associated with these complications.     

Effect of silver-coated urinary catheters: efficacy, cost-effectiveness, and antimicrobial resistance

BACKGROUND: Urinary tract infections (UTIs) are the most common nosocomial infection experienced by patients in United States hospitals and are responsible for significant morbidity and excess hospital costs. The purpose of this study was to determine the efficacy of a silver alloy, hydrogel-coated, urinary catheter in the prevention of catheter-associated UTI, to assess the cost effectiveness of the coated catheter, and to test for the emergence of silver-resistance in urinary microbial isolates. METHODS: A 2-year prospective surveillance study in 10 patient care units was conducted to determine the rate of catheter-associated UTI. Historic control data was utilized to assess the effect of the coated catheter. A cost-effectiveness analysis was conducted using a range of cost estimates. Silver susceptibility was determined for microbes responsible for catheter-associated UTI. RESULTS: Data were analyzed using a Poisson regression model. The rate of catheter-associated UTI fell from 6.13/1000 catheter-days during the period 1999-2000 to 2.62/1000 catheter-days during 2001-2002 ( P = .002). Calculated cost savings varied widely. Modest savings were achieved at the realistic lower cost estimates. No silver-resistant microbes were recovered in the susceptibility tests. CONCLUSIONS: The introduction of a silver alloy, hydrogel-coated urinary catheter was associated with a significant decline in nosocomial UTI and cost savings over the range of cost estimates. Silver-resistant urinary pathogens were not recovered from patients experiencing catheter-associated UTI during the study period.     

Novel approaches to the diagnosis, prevention, and treatment of medical device-associated infections

The pathogenesis of device-associated infections is related to biofilm bacteria that exhibit distinct characteristics with respect to growth rate, structural features, and protection from host immune mechanisms and antimicrobial agents when compared with planktonic counterparts. Biofilm-associated infections are prevented, diagnosed, and treated differently from infections not associated with biofilms. This article reviews innovative concepts for the prevention of biofilm formation, and novel treatment approaches. Specific approaches for the diagnosis and prevention of catheter-associated urinary tract and bloodstream infections, as well as infections associated with orthopedic implants and cardiovascular implantable electronic devices, are also discussed.     

Amdinocillin treatment of catheter-associated bacteriuria in rabbits

The effect of the beta-lactam antibiotic, amdinocillin, on the bacterial biofilm adherent to the Foley catheter surface, the bacterial microcolonies attached to the urinary bladder mucosa, and on planktonic bacteria in the urine was studied in a rabbit model of the closed urinary catheter drainage system. Progressively increasing the dose of antibiotic in this experimental catheter-associated urinary tract infection model first eliminated the bacterial population adherent to the bladder mucosa and then the planktonic population in the urine. The bacterial biofilm on the Foley catheter could be eradicated only by the highest dose of antibiotic (400 mg/kg). Scanning electron microscopy showed a gradual deterioration of bacterial biofilm and reduction in bacterial numbers with increasing antibiotic dosages. These data suggest that antibiotics used in short-term catheterization may reduce the serious sequelae associated with catheter-related infections by clearing the potentially dangerous bladder mucosal bacterial populations and urine planktonic bacteria.     

Prevention and Treatment of Urinary Catheter-Associated Infections

Catheter-associated urinary tract infections (CA-UTIs) are the most common nosocomial infection worldwide. Prolonged catheterization is the most important risk factor for CA-UTIs. As is the case with all device-related infections, the biofilm plays a central role in the pathogenesis of CA-UTIs. The diagnosis is often difficult, given the lack of good diagnostic tests. The most effective way to prevent infection is to limit catheter use and discontinue the catheter when no longer needed. Catheter removal or exchange is also useful in management. This review summarizes and analyzes the results of published studies of CA-UTIs and assesses the role of prevention approaches and management strategies.     

Nosocomial infections in medical-surgical intensive care units in Argentina: attributable mortality and length of stay

BACKGROUND: Nosocomial infections are an important public health problem in many developing countries, particularly in the intensive care unit (ICU). Limited data exists on the incidence and burden of nosocomial infection in the ICU in Argentina. METHODS: We performed baseline prospective nosocomial infection surveillance of all patients for 6 months in 3 medical-surgical ICUs (MS-ICUs) in Argentina (2 months in each ICU). Nosocomial infections were identified using the Centers for Disease Control and Prevention National Nosocomial Infections Surveillance definitions. Overall and site-specific nosocomial infection rates, attributable mortality, and excess length of hospital stay were calculated. RESULTS: The overall nosocomial infection rate was 27% and 90 per 1000 patient-days. The most common site of infection was catheter-related bloodstream infection (32%), followed by ventilator-associated pneumonia (25%), and catheter-associated urinary tract infection (23%). The rate of central catheter-associated bloodstream infection in the MS-ICU was 44.61 per 1000 device-days, with an attributable mortality of 25%, and 12 attributable extra days of hospital stay. The urinary catheter-associated urinary tract infection rate in the MS-ICU was 22.55 per 1000 urinary catheter-days, with an attributable mortality of 5%, and 5 excess extra days of hospital stay. The ventilator-associated pneumonia rate in the MS-ICU was 50.87 per 1000 ventilator-days with an attributable mortality of 35%, and 10 attributable extra days of hospitalization. CONCLUSION: Our study finds high rates of nosocomial infections in ICUs in Argentina, associated with a considerable attributable mortality and excess length of stay. Ongoing targeted surveillance and implementation of infection control strategies is necessary to control this growing problem.     

Nursing leadership and the reduction of catheter-associated urinary tract infection

The prevention of infections continues to be a challenge for many hospitals. We examined specific features of nursing leadership and found improvements in leadership were associated with a decrease in catheter-associated urinary tract infection. Infection prevention efforts in acute care hospitals should focus on nurse leaders and their ability to provide the support necessary to improve care delivery—support that could be instrumental in the reduction and the elimination of catheter-associated urinary tract infection.     

Bacterial biofilms and catheters: A key to understanding bacterial strategies in catheter-associated urinary tract infection

Despite major technological improvements in catheter drainage systems, the indwelling Foley catheter remains the most common cause of nosocomial infection in medical practice. By approaching this common complicated urinary tract infection from the perspective of the biofilm strategy bacteria appear to use to overcome obstacles to produce bacteriuria, one appreciates a new understanding of these infections. An adherent biofilm of bacteria in their secretory products ascends the luminal and external surface of the catheter and drainage system from a contaminated drainage spigot or urethral meatus into the bladder. If the intraluminal route of bacterial ascent is delayed by strict sterile closed drainage or addition of internal modifications to the system, the extraluminal or urethral route assumes greater importance in the development of bacteriuria, but takes significantly longer. Bacterial growth within these thick coherent biofilms confers a large measure of relative resistance to antibiotics even though the individual bacterium remains sensitive, thus accounting for the failure of antibiotic therapy. With disruption of the protective mucous layer of the bladder by mechanical irritation, the bacteria colonizing the catheter can adhere to the bladder's mucosal surface and cause infection. An appreciation of the role of bacterial biofilms in these infections should suggest future directions for research that may ultimately reduce the risk of catheter-associated infection.     

A randomized crossover study of silver-coated urinary catheters in hospitalized patients

BACKGROUND: Urinary tract infections (UTIs) account for 30% to 40% of nosocomial infections resulting in morbidity, mortality, and increased length of hospital stay. OBJECTIVE: To assess the efficacy of a silver-alloy, hydrogel-coated latex urinary catheter for the prevention of nosocomial catheter-associated UTIs. METHODS: A 12-month randomized crossover trial compared rates of nosocomial catheter-associated UTI in patients with silver-coated and uncoated catheters. A cost analysis was conducted. RESULTS: There were 343 infections among 27,878 patients (1.23 infections per 100 patients) during 114,368 patient-days (3.00 infections per 1000 patient-days). The relative risk of infection per 1000 patient-days was 0.79 (95% confidence interval, 0.63-0.99; P =.04) for study wards randomized to silver-coated catheters compared with those randomized to uncoated catheters. Infections occurred in 291 of 11,032 catheters used on study units (2.64 infections per 100 catheters). The relative risk of infection per 100 silver-coated catheters used on study wards compared with uncoated catheters was 0.68 (95% confidence interval, 0.54-0.86; P =.001). Fourteen catheter-associated UTIs (4.1%) were complicated by secondary bloodstream infection. One death appeared related to the secondary infection. Estimated hospital cost savings with the use of the silver-coated catheters ranged from $14,456 to $573,293. CONCLUSIONS: The risk of infection declined by 21% among study wards randomized to silver-coated catheters and by 32% among patients in whom silver-coated catheters were used on the wards. Use of the more expensive silver-coated catheter appeared to offer cost savings by preventing excess hospital costs from nosocomial UTI associated with catheter use. Arch Intern Med. 2000;160:3294-3298.     

Device-associated nosocomial infection rates in intensive care units in four Mexican public hospitals

BACKGROUND: Routine surveillance of nosocomial infections has become an integral part of infection control and quality assurance in US hospitals. METHODS: As part of the International Nosocomial Infection Control Consortium, we performed a prospective nosocomial infection surveillance cohort study in 5 adult intensive care units of 4 Mexican public hospitals using the Centers for Disease Control and Prevention National Nosocomial Infections Surveillance system definitions. Site-specific nosocomial infection rates were calculated. RESULTS: The overall nosocomial infection rate was 24.4% (257/1055) and 39.0 (257/6590) per 1000 patient days. The most common infection was catheter-associated bloodstream infection, 57.98% (149/257), followed by ventilator-associated pneumonia, 20.23% (52/257), and catheter-associated urinary tract infection, 21.79% (56/257). The overall rate of catheter-associated bloodstream infections was 23.1 per 1000 device-days (149/6450); ventilator-associated pneumonia rate was 21.8 per 1000 device-days (52/2390); and catheter-associated urinary tract infection rate was 13.4 per 1000 device-days (56/4184). CONCLUSION: Our rates are similar to other hospitals of Latin America and higher than US hospitals.     

Clinical complications of urinary catheters caused by crystalline biofilms: something needs to be done

This review is largely based on a previous paper published in the journal Spinal Cord. The care of many patients undergoing long‐term bladder catheterization is complicated by encrustation and blockage of their Foley catheters. This problem stems from infection by urease‐producing bacteria, particularly Proteus mirabilis. These organisms colonize the catheter forming an extensive biofilm; they also generate ammonia from urea, thus elevating the pH of urine. As the pH rises, crystals of calcium and magnesium phosphates precipitate in the urine and in the catheter biofilm. The continued development of this crystalline biofilm blocks the flow of urine through the catheter. Urine then either leaks along the outside of the catheter and the patient becomes incontinent or is retained causing painful distension of the bladder and reflux of urine to the kidneys. The process of crystal deposition can also initiate stone formation. Most patients suffering from recurrent catheter encrustation develop bladder stones. P. mirabilis establishes stable residence in these stones and is extremely difficult to eliminate from the catheterized urinary tract by antibiotic therapy. If blocked catheters are not identified and changed, serious symptomatic episodes of pyelonephritis, septicaemia and endotoxic shock can result. All types of Foley catheters including silver‐ or nitrofurazone‐coated devices are vulnerable to this problem. In this review, the ways in which biofilm formation on Foley catheters is initiated by P. mirabilis will be described. The implications of understanding these mechanisms for the development of an encrustation‐resistant catheter will be discussed. Finally, the way forward for the prevention and control of this problem will be considered.     

Use of silver-hydrogel urinary catheters on the incidence of catheter-associated urinary tract infections in hospitalized patients

BACKGROUND: Urinary tract infections (UTIs) account for 40% of all nosocomial infections, and about 80% of these are associated with the use of urinary catheters. They not only contribute to excess morbidity and mortality, but they also significantly add to the cost of hospitalization. Clinical trials with silver-coated urinary catheters have shown conflicting results. However, recent trials with silver-hydrogel urinary catheters have shown a reduction in nosocomial UTIs, and these catheters appear to offer cost savings. METHOD: The University of Massachusetts Medical Center is a teaching, tertiary hospital with 18% of its beds in intensive care units. The silver-hydrogel urinary catheters were introduced in October 1997. The rate of catheter-associated UTIs with silver-hydrogel urinary catheter use was compared with a historical baseline UTI rate that was established for January 1996 and January 1997 with the standard, noncoated catheters. The cost of a nosocomial catheter-associated UTI was estimated by calculating the hospital charges resulting from all urinary catheter-associated UTIs in 1 month. A cost-analysis of silver-hydrogel urinary catheter use was performed. RESULTS: The rate of catheter-associated UTIs for noncoated catheters was 4.9/1000 patient-days compared with 2.7/1000 patient-days for the silver-hydrogel catheters, a reduction of 45% (P =.1). The average cost (calculated with hospital charges) of a catheter-associated UTI at our institution was estimated to be $1214.42 US dollars, with a median of $613.72 US dollars. The estimated cost-saving ranged from $12,563.52 US dollars to $142,314.72 US dollars. CONCLUSIONS: The use of silver-hydrogel urinary catheters resulted in a nonsignificant reduction in catheter-associated UTIs and a modest cost-saving.     

The International Nosocomial Infection Control Consortium (INICC): goals and objectives, description of surveillance methods, and operational activities

We have shown that intensive care units (ICUs) in countries with limited resources have rates of device-associated health care-associated infection (HAI), including central line-related bloodstream infection (CLAB), ventilator-associated pneumonia (VAP), and catheter-associated urinary tract infection (CAUTI), 3 to 5 times higher than rates reported from North American, Western European, and Australian ICUs. The International Nosocomial Infection Control Consortium (INICC) is an international ongoing collaborative HAI control program with a surveillance system based on that of the US National Healthcare Safety Network. The INICC was founded 10 years ago to promote evidence-based infection control in hospitals in limited-resource countries and in hospitals of developed countries without sufficient experience in HAI surveillance and control, through the analysis and feedback of surveillance data collected voluntarily by the member hospitals. It developed from a handful of South American hospitals in 1998 to a dynamic network of 98 ICUs in 18 countries, and is the only source of aggregate standardized international data on HAI epidemiology. Herein we report the criteria and mechanisms for gaining membership in INICC; the training of personnel in INICC hospitals; the INICC protocol for outcome surveillance of CLABs, VAPs, and CAUTIs in ICUs, microorganism profiles, bacterial resistance, antibiotic use, extra length of stay, extra costs, extra mortality, and risk factor analysis, and for process surveillance, including compliance rates for hand hygiene, vascular catheter care, urinary catheter care, and measures for prevention of VAP; and the use of surveillance data feedback as a powerful weapon for control of HAIs. The INICC will continue to evolve in its quest to find more effective and efficient ways to assess patient risk and improve patient safety in hospitals.     

Complicated urinary tract infections

This review highlights recent findings regarding complicated urinary tract infections (UTIs). We review recently published randomized controlled trials, Cochrane reviews, and meta-analyses. Topics covered include new findings on the genetics of acute pyelonephritis, methods to prevent catheter-associated UTI, duration of treatment for catheter-associated UTI, and reimbursement changes for Medicare patients who develop nosocomial UTI in US hospitals. Future studies on complicated UTI are needed to better define this complex disease and its management and to confirm the clinical significance of different prevention strategies.     

Promoting continence: simple strategies with major impact

Urinary incontinence is a common problem, especially among women, yet it remains underreported and undertreated. This is partly due to patients' beliefs that little can be done and partly due to healthcare professionals' perception that treatment is limited to surgery, advanced behavioral strategies requiring specialized equipment, or containment devices. Nurses are in a strategic position to reduce the incidence of incontinence by teaching bladder health strategies (ie, fluid management, appropriate voiding intervals, constipation prevention, weight control, smoking cessation, and pelvic muscle exercises), actively assessing patients for incontinence, and initiating appropriate referrals and primary interventions. Patients with significant neurologic deficits, structural abnormalities such as pelvic organ prolapse, or urinary retention should be referred for further workup. However, most patients can be treated with primary continence restoration strategies, which include identifying and correcting reversible factors such as urinary tract infection or atrophic urethritis; instruction in pelvic floor muscle exercises; and instruction regarding urge inhibition strategies. Implementing these simple strategies can significantly improve bladder function and continence in the majority of patients.     

Developing an educational resource for parents on pediatric catheter-associated urinary tract infection (CAUTI) prevention

BackgroundPediatric catheter-associated urinary tract infection (CAUTI) prevention guidelines encourage family engagement; however, there is a dearth of research on parent-facing CAUTI prevention resources. We aimed to meet the learning needs of parents about CAUTI prevention in the hospital by developing and refining an educational pamphlet with parents.MethodsPhase 1: We compiled existing evidence from CAUTI prevention guidelines and conducted a focus group with parents to form learning objectives. Phase 2: We developed prototype design elements, tested initial designs with a survey, and conducted qualitative participatory design sessions with parents to iteratively refine the pamphlet until design saturation was reached.ResultsWe identified the following key themes and preferences: (1) Clear boundaries for engagement (e.g., parents would not be emptying the catheter); (2) Positive, actionable framing (e.g., what should proper catheter positioning look like?); (3) What to expect (e.g., is the catheter painful for my child?); (4) Parents considered both their and their child's comprehension of the content when providing feedback.ConclusionsOverall, we demonstrated the utility of remote participatory design methods in developing and refining a CAUTI prevention resource based on parents’ preferences. Future research should consider adapting these methods and implementing formal evaluation for comprehension for eventual integration into clinical practice.     

Factors related to the accurate application of NHSN surveillance definitions for CAUTI and CLABSI in Texas hospitals: A cross-sectional survey

Previous studies indicate variability in the accurate application of National Healthcare Safety Network surveillance criteria with limited data on possible contributing factors. In this cross-sectional, convenience sampled web-based survey sent to members of Texas infection prevention and control organizations, training, experience, and time spent on surveillance was collected and assessed including 2 case studies. Our results indicate correct identification of catheter-associated urinary tract infection (CAUTI) and central line-associated bloodstream infection (CLABSI) criteria may be associated with 2019 National Healthcare Safety Network training (CAUTI: aOR = 0.17, 95% CI: 0.04, 0.80; CLABSI: aOR = 0.45, 95% CI: 0.045, 4.56) and increased years of infection prevention experience (CAUTI: aOR = 1.35, 95% CI: 0.42, 4.33; CLABSI: aOR = 1.23, 95% CI: 0.24, 6.38). Routinely performing more hours of surveillance may increase accuracy of CLABSI identification, but not CAUTI.