Urinary drainage may be managed by an indwelling catheter in several circumstances.1,2 Short-term catheterization (usually defined as persisting for 2 weeks or less) may be undertaken after urologic, gynecologic, neurologic, or abdominopelvic surgery in critically ill patients requiring close monitoring of urine output during the acute phase after a paralyzing neurologic disorder and in cases of acute urinary retention. The indications for a long-term indwelling catheter (persisting for more than 2 weeks) are more restrictive. They are: (1) urinary retention associated with bladder outlet obstruction that cannot be managed by other methods, (2) urinary incontinence coexisting with urinary retention that cannot be managed by other methods, (3) delayed healing of a high-stage pressure ulcer owing to urinary incontinence, and (4) palliative care settings where routine toileting is compromised by pain or immobility.

Nevertheless, many patients are managed by long-term indwelling catheters, and the catheters are often left in place for months to years. For example, it has been estimated that approximately 100,000 long-term care facility residents in the United States3 and 4% of homebound elders in England are managed by catheters.4 Despite its initial convenience for care providers (and sometimes for patients), long-term catheterization is viewed as a "final option" because of the risk for complications, including chronic renal inflammation, urinary calculi, urinary incontinence owing to urethral erosion or pain overactive detrusor contractions (bladder spasms), bacteremia, renal inflammation, compromised renal function, bacteremia, sepsis, and death.1 Each of these factors is associated with chronic bacterial colonization and recurring urinary tract infection (UTI) prevalent among patients managed by an indwelling catheter.1-5

A UTI is defined as an inflammatory response of the epithelium of the urinary tract to invasion and colonization by a pathogen (usually a bacterial species).6 It is typically associated with pyuria and bacteriuria. The majority of UTIs occur in otherwise healthy women. They are characterized as uncomplicated or domiciliary and produce characteristic symptoms, including dysuria, suprapubic pain, frequent voiding, and bothersome urgency or discomfort if urination is postponed. In contrast, UTI occurring in persons with an indwelling catheter are characterized as complicated. Unlike domiciliary infections, they are more likely to involve multiple pathogens and resistant bacterial species, and they typically arise from a bladder colonized by bacteria, many of which dwell within an antibiotic-resistant biofilm. Because they arise from a milieu of chronic bacterial colonization, the presence of bacteriuria and pyuria on urinalysis alone are not sufficient indications for treatment. Only symptomatic UTI should be treated in the patient with an indwelling catheter. Catheter-associated UTIs do not produce the characteristic symptoms seen in patients with domiciliary infections.7,8 Instead, common symptoms include hematuria, fever, or bladder spasm (painful overactive detrusor contractions, often accompanied by catheter bypassing). Catheter-associated UTIs also lead to more serious sequelae in many patients, including infection of the renal parenchyma (pyelonephritis) or blood stream (urosepsis), and they require prolonged antimicrobial therapy that rarely resolves the underlying bacteriuria. This Evidence-Based Report Card briefly reviews guidelines for prevention of catheter-associated UTI promulgated by the US Centers for Disease Control2 and the Joanna Briggs Institute based in the United Kingdom9 and identifies the evidence base for nursing strategies designed to reduce UTIs in persons with indwelling urethral catheters.

Questions about indications for catheter insertion and the timing of catheter removal have been excluded from this Evidence-Based Report Card. Rather, this article focuses on nursing strategies to reduce UTI risk among patients with an existing indwelling catheter. In addition, evidence related to the use of suppressive or prophylactic drugs is excluded because decisions about the use of long-term antimicrobial therapy are primarily completed by physicians or advanced practice nurses.

Methods

To identify nursing interventions believed to prevent catheter-associated UTI, a systematic search of healthcare literature was undertaken using the key words "indwelling catheter," "urinary catheterization," "urinary tract infection," "guidelines," "clinical practice guidelines," and "best practice." MEDLINE, CINAHL, and the Cochrane Database for Systematic Reviews were reviewed from January 1996 to November 2003. Because of a paucity of relevant citations, the search was ultimately expanded to include 2 Web-based search engines (Google and Yahoo) and the search engine provided on the Web page of the US Center for Disease Control (CDC) using the key words identified.

Evidence supporting or refuting the effectiveness and safety each nursing intervention promulgated within these guidelines was sought via a systematic literature review. MEDLINE and CINAHL databases were searched from 1966 to November 1, 2003, using the previously listed key words, as well as key words suggested by specific interventions. The Cochrane Database for Systematic Reviews, Cochrane Central Register for Controlled Trials, ACP Journal Club, and Database for Abstracts for Reviews of Effects were also searched for each identified intervention. Research cited is limited to English-language articles or abstracts using human subjects.

Question 1: What Nursing Strategies to Reduce Catheter-Associated UTI are Promulgated in National Guidelines on This Topic?

Two national guidelines for reducing catheter-associated UTI were identified.9,10 The US CDC published a Guideline for Prevention of Catheter-Associated Urinary Tract Infections in 1981.2 Although the guideline remains posted on the center's Web page, the CDC describes the materials as being maintained for "historical purposes" and notes that they have not been updated since October 1998. However, additional search of their site failed to reveal a more recent guideline and this Evidenced Based Report Card will use the 1981 guideline. The CDC guideline noted that recommendations for clinical practice are based on literature review, but the methods used to identify research were not specified. The strength of each recommendation falls into 1 of 3 categories: (1) strongly recommended for adoption, (2) moderately recommended for adoption, and (3) weakly recommended for adoption. Table 1 summarizes the clinical practice recommendations found in this guideline and compares them to interventions promulgated by the Joanna Briggs Institute's guidelines.9

Table 1 Clinical Practice Guidelines for Preventing Catheter-Associated Urinary Tract Infection

The Joanna Briggs Institute is a Web-based resource for evidence-based and best practice guidelines. The institute is located in the Royal Adelaide Hospital, South Australia (http://www.joannabriggs.edu.au). A guideline for preventing UTI in patients with a short-term indwelling catheter was published in 2000. It is described as a best practice document, but recommendations for clinical practice are based on systematic literature review, and strength of underlying evidence is ranked. The strength of recommendations is divided into 4 levels: Level 1 evidence based on systematic review of multiple relevant randomized trials, level 2 based on findings from at least 1 properly designed randomized clinical trial, level 3 based on results of quasi-experimental studies, and level 4 based on expert opinion, anecdotal clinical experience, or descriptive studies. Table 1 summarizes the clinical practice recommendations found in this guideline and compares them to interventions promulgated by the US CDC.2

Web-based search engines and professional literature databases were also searched in an attempt to find Canadian or British guidelines for catheter associated UTI. Several Web pages were identified, but they contained policies for an individual healthcare facility or cited the CDC or Brigg guidelines as primary references for their practice recommendations.

Question 2: Do Elements of Catheter Design (Size and Material of Construction) Reduce Subsequent UTI Risk?

Several components of catheter design have been associated with a greater or lesser risk of UTI. The CDC Guidelines2 include a level II (moderate strength) recommendation that a smaller bore catheter be used whenever possible. However, systematic review of the literature reveals no research supporting or refuting the effectiveness of this strategy for UTI prevention.

The Briggs Best Practice Document states that selection of a silver alloy may reduce UTI risk, as compared to catheters made of silicone or latex. One systematic review was located in the Database for Reviews for Effectiveness (DARE) and MEDLINE databases that specifically addressed this question.10,11 It reviewed summarized findings from 8 studies published between 1986 and 1998, including 6 randomized clinical trials and 2 quasi-experimental studies, that compared silver-coated and uncoated urinary catheters for evidence of bacteriuria (Table 2).12-19 Meta-analysis revealed that silver alloy catheters are more effective in preventing bacteruria than are silver oxide or uncoated catheters. In addition, when 3 studies providing gender specific results were analyzed, data revealed that women benefit from silver-coated catheters although men do not.

Table 2 Do Silver-Coated Catheters Reduce the Risk for Catheter-Associated Urinary Tract Infection?

Although the findings of this meta-analysis are promising, it must be highlighted that the outcome of bacteriuria was used in these trials as a surrogate for the more clinically relevant outcome, symptomatic UTI. This distinction is particularly important, given the high prevalence of bacteriuria as compared to the far lower prevalence of symptomatic UTI.20 The authors also pointed out that further research is needed on cost effectiveness because silver alloy catheters may be approximately twice as expensive as uncoated ones.

Given the thoroughness of this review, no additional systematic review was undertaken for research published before 1998, but a search was conducted for studies published from 1999 to 2003. This search revealed 3 additional studies; 1 focused on the efficacy of silver-coated catheters for the prevention of UTI21 and 2 explored cost effectiveness related to their use.22,23 Newton and associates21 retrospectively compared the incidence of symptomatic UTI in burn patients. Each patient was managed for an equal period of time with an uncoated latex catheter, followed by an equal period during which a catheter was inserted that was coated with a silver alloy. The UTI rate was 7.2 per 1,000 catheter days when burn patients were managed with uncoated catheters as compared to 4.4 per 1000 catheter days when managed with a silver-coated catheter.

Two studies examined the cost-effectiveness of silver-coated catheter use. Saint and colleagues22 evaluated direct costs related to the use of silver alloy catheters using a simulated cohort of 1,000 patients managed by indwelling catheters for a period of 2 to 10 days. Using a base-case analysis, it was estimated that silver-coated catheters would reduce the incidence of symptomatic UTI by 47% and result in a 44% reduction in associated urosepsis. Based on these projections, silver-coated catheters provided overall cost savings when compared to uncoated catheters.

Bologna and coworkers23 compared costs associated with use of uncoated short-term indwelling catheters with a hydrogel catheter coated with a silver alloy. Critical care units from 5 hospitals participated in the study, representing a total of 108 beds. Baseline measurements ranged from 3 to 12 months, during which all participating hospitals used uncoated catheters, followed by a blinded switch to silver-coated catheters for a period of 7-19 months. Diagnosis of catheter-associated UTI was based on prospective surveillance via each facility's infection control clinician. A UTI was diagnosed when any of 3 conditions was fulfilled: (1) positive urine culture and sensitivity test results, (2) antimicrobial usage, or (3) retrospective chart review. The number of catheters used during observation periods was also tracked. Unadjusted catheter-associated UTI rates were significantly reduced when patients were managed by silver-coated catheters, but this difference disappeared when multifactorial analysis accounted for the following factors: institution, critical care unit type, time of year, and severity of illness. A cost analysis was performed at an institution that demonstrated a statistically significant reduction in catheter-associated UTI rate. It revealed cost savings just more than $98,000 when switching to silver alloy catheters.

Question 3: Does Sterile Technique During Insertion Prevent UTI?

The use of sterile technique was advocated by the CDC guidelines2 and by multiple review articles.1,24,25 However, the Briggs Institute Best Practice document states that the use of sterile technique does not reduce UTI risk. This guideline and a systematic literature review undertaken for this article revealed only 1 randomized clinical trial focusing on the influence of sterile vs clean technique for catheter insertion. Carpeti and coworkers26 randomly assigned 156 subjects to undergo sterile vs clean insertion technique during elective surgery. Sterile technique was described as hand scrubbing for 4 minutes, donning sterile gloves and gowns, and employing "strict sterile technique," including a catheter insertion kit and perineal cleansing using a povidone-iodine solution. Clean technique was described as hand washing using soap and water, donning nonsterile gloves, and cleansing the patient's perineum only if visible soiling or debris were observed; no catheter insertion pack was used, and water alone was used to cleanse the perineum. The main outcome measure (bacteriuria) was measured as a nominal variable immediately 3 days after catheterization. Results revealed that use of sterile technique did not reduce bacteriuria occurrence when compared to subjects catheterized via sterile technique. Literature review revealed no additional study directly comparing insertion technique in patients managed by indwelling catheterization.

Although a systematic literature review revealed only 1 study that directly addressed the question of insertion technique among patients managed by indwelling catheterization, 2 other studies were found that focused on specific components of insertion technique. Pickard and Grundy27 compared 2 insertion techniques in a group of 46 patients with spinal cord injuries. A more rigid sterile technique required a 3-minute hand wash from fingers to elbows, followed by donning a sterile gown and gloves. The shorter method required 30-second hand washing followed by double gloving. Results revealed no differences between the methods, prompting the authors' facility to abandon the more rigid technique and adopt the shorter method.

Webster and colleagues28 compared periurethral-cleansing techniques before catheterization in a group of 436 women undergoing obstetric care. Subjects were randomly assigned to undergo periurethral cleansing using a chlorhexidine solution or tap water and sterile urine specimens were obtained and analyzed for bacteriuria. No statistically significant differences were found when techniques were compared indicating no advantage to the use of an antiseptic solution before catheterization.

Question 4: Does Routine Care of the Urethral Meatus Reduce UTI risk?

Neither guideline recommends routine meatal care for patients with indwelling catheters.2,9 Five studies were identified that focused on meatal care as a preventive technique for UTI in patients with indwelling urinary catheters. Burke and associates29 studied the efficacy of daily meatal care as compared to no care in 200 patients. Subjects were randomized to receive (1) twice-daily meatal care comprising cleansing with a povidone-iodine solution and application of a povidone-iodine ointment, (2) once-daily meatal cleansing with a nonantiseptic solution containing soap and water, or (3) no special meatal care. Contrary to what was described as a best practice policy for that time (the research report was published in 1981), subjects randomized to receive meatal cleansing combined with application of an ointment had higher bacteriuria rates when compared to those receiving no special care, indicating that cleansing plus antiseptic ointment application should be discontinued because of its harmful effects. In a second report obtained from a larger group of 214 patients, Burke and colleagues30 randomly assigned 20 subjects to receive meatal care comprising cleansing and application of a polyantibiotic ointment twice daily or no special care. In contrast to their first study, bacteriuria rates were lower among subjects who received meatal care as compared to those receiving no special care. However, the researchers further noted that subjects enrolled in this study were high-risk female patients undergoing short-term catheterization and that the benefits associated with meatal care are of slight magnitude.

Classen and coworkers31 combined daily meatal care, disinfection of the outflow tube of the drainage bag with a povidone-iodine solution, and a sealed catheter system in an attempt to reduce the risk of catheter-associated bacteriuria. This 3-strategy method was compared to use of a sealed system alone in a group of 29 patients. The bacteriuria rate for the triple-intervention group was 4.7% as compared to a rate of 4.9% for the untreated group, a slight and statistically nonsignificant difference. Based on these findings, the authors concluded that meatal care combined with routine disinfection of the drainage bag emptying tube does not reduce bacteriuria or UTI risk.

Huth and colleagues32 evaluated the effectiveness of 1% silver sulfadiazine cream in an attempt to prevent catheter-associated UTI. A randomized clinical trial was completed that involved 696 subjects with short-term indwelling catheters randomized to receive either silver sulfadiazine cream twice daily or routine cleansing with no application of cream. Bacteriuria rates were not significantly different between the 2 groups.

Matsumoto and associates33 compared 3 meatal care techniques in a group of 55 patients undergoing elective surgical procedures. Subjects were divided into 3 groups: (1) daily application of povidone-iodine solution, (2) twice-daily application of povidone-iodine solution, and (3) once-daily application of povidone-iodine cream. No randomization procedures pertaining to group assignment were described. Outcome measures included bacterial cultures of the urine and urethral meatus. Data were collected up to 14 days. Men experienced greater reductions in bacterial colonization at the level of the urethral meatus than did women. Nevertheless, bacteriuria (operationally defined as a UTI by these researchers) was present in all groups. By day 14, bacteriuria occurred in 100% of men managed by daily application of povidone-iodine cream, in 36% of men managed by once daily application solution, and none of the men managed with twice-daily application. Bacteriuric rates in women were 57% of those managed by once-daily application, 62% of those managed by application of povidone-iodine cream, and 29% in the group undergoing twice-daily application of povidone-iodine. Although these results support twice-daily application of povidone-iodine ointment, they must be interpreted with considerable care because no control group (subjects receiving no routine meatal care) was included and randomization was not incorporated into the study design.

The CDC guidelines2 reference an additional study published in 1976 by Britt and associates34 that concludes that routine meatal care is effective in preventing catheter-associated UTI. However, the report appears only in the gray literature (abstract only), and details could not be located for further analysis and consideration.

Question 5: Does Securing the Catheter Reduce UTI Risk?

The CDC guidelines2 strongly recommend securing the catheter after insertion to prevent movement and urethral traction, but the Briggs Institute best practice document9 does not mention this strategy. The CDC guidelines2 base this recommendation on a single supporting study published by Desautels and associates35 in 1962, before archives maintained by MEDLINE or CINAHL electronic databases. This nonexperimental study describes the experiences of the authors using multiple strategies in an attempt to reduce catheter-associated UTI, including insertion of catheters using aseptic technique, cleansing of the distal urethra and meatus at the time of insertion with an antiseptic solution, insertion of a catheter impregnated with tetramethylthiuramdisulphide (a substance with antimicrobial action), and twice-daily application of a benzalkonium dressing to prevent ascending bacterial migration and catheter migration within the urethra. Clearly, this strategy differs significantly from existing methods of securing catheters using a strap or adhesive device designed to prevent traction or inadvertent catheter removal. Systematic review of MEDLINE and CINAHL databases from 1966 to November 2003 failed to reveal any study supporting or refuting the effect of catheter securing on UTI risk.

Question 6: Does the Maintenance of a Closed Drainage System Reduce the Risk of UTI?

Both national guidelines recommend maintenance of a closed system as a strategy to prevent UTI.2,9 Systematic literature review revealed 8 studies that directly addressed the effect of a sealed drainage system on UTI risk. Five studies compared closed drainage systems to systems that were open for purposes of irrigation or drainage of collection vessels. Kunin and McCormack36 evaluated the effectiveness of a closed drainage indwelling catheter system on 1,166 consecutive patients managed in a single acute care facility. This strategy was introduced as part of a larger program designed to improve indwelling catheter management, including aseptic insertion, regular drainage of urine collection bags to avoid soiling or overt contamination of drainage ports, twice-daily perineal cleansing, education designed to ensure catheter drainage bags are not inverted or above the level of the symphysis pubis, and avoidance of irrigation, unless blockage is suspected. The authors found that 77% of patients managed by a closed drainage system retained sterile urine at the time of discharge. Garibaldi and coworkers37 evaluated bacteriuria in 405 hospitalized patients and found a bacteriuria rate of 23% after short-term indwelling catheterization for 1-14 days. They noted that breaks in the closed drainage system to drainage bag increased the risk for bacteriuria.

Platt and associates38 completed a randomized clinical trial indicating that catheters with preconnected sealed junctions reduced UTI risk compared to catheters without such junctions. Patients managed by a nonsealed catheter had 2.7 times the risk for a UTI than those managed by a sealed system. Furthermore, only 4% of the 220 subjects who did not develop a UTI requiring antibiotic therapy and were managed with a sealed catheter system had bacteriuria as compared to 14% of those with unsealed systems. Based on these outcomes, the authors concluded that a sealed catheter system reduces both morbidity and mortality associated with UTI in patients managed by a short-term indwelling catheter in a hospital setting.

DeGroot-Kosocharoen et al39 compared a closed preconnected system to a nonsealed system in 202 hospitalized men. After a mean catheterization time of 6.4 and 7.6 days in groups randomly assigned to sealed and nonsealed systems, respectively, they found no statistically significant differences in the incidence of bacteriuria or symptomatic UTI. Huth and associates40 compared incidence of bacteriuria in a randomized clinical trial involving 1,740 hospitalized patients. They also found no statistical differences in the incidence of bacteriuria. Subsequent multivariate analysis revealed that female gender and lack of systematic antibiotic and not use of a preconnected sealed catheter system predicted the presence or absence of bacteriuria.

Two studies were found that compared different types of closed drainage systems. Wille et al41 compared time of onset of bacteriuria and overall incidence in (1) a closed urinary drainage system incorporating an antireflux valve and (2) a closed system incorporating a preconnected coated catheter, tamper-discouraging seal at the catheter-drainage tubing junction, drip chamber, antireflux valve, hydrophobic drainage vent in the collection bag, and a povidone-iodine-releasing cartridge at the drainage port. One hundred eighty one subjects with an indwelling catheter anticipated to remain in place for at least 48 hours were randomly assigned to one of the systems, and the bacteriologic status of the urine was monitored every 24 hours. No differences were found in bacteriuria rates, and the authors concluded that the additional features described in the more complex system described provided no benefit as compared to a simple sealed system. Leone and colleagues42 performed a similar comparison in a group of 224 consecutive patients managed in a critical care setting, with the exception that group assignment was not randomized. They also found no statistical differences in frequency of bacteriuria.

Although a closed drainage system is feasible in the patient managed by a short-term catheter, it is rarely feasible for the patient managed by a long-term indwelling catheter, particularly when managed in a home health or long-term care setting. Wilson et al43 compared a catheter valve to a "standard" drainage system in 100 subjects managed by long-term indwelling catheterization. Subjects were randomly assigned to management by a standard drainage system or one that incorporated a catheter valve, a small device that prevents reflux of urine from drainage tubing or collection bag into the catheter or bladder vesicle. The incidence of catheter-associated UTI was not statistically different among subjects assigned to the catheter valve.

Question 7: Does Irrigation of the Catheter and/or Bladder Reduce UTI Risk?

Both guideline documents2,9 recommend limited application of irrigation; the CDC guidelines limit irrigation to cases of catheter blockage, and both warn that irrigation with antiseptic or antimicrobial solutions does not prevent UTI risk. Two studies directly evaluated the effect of bladder irrigation on UTI risk. Brunn and Digranes44 evaluated the effect of intermittent irrigation with 4 solutions: (1) saline, (2) 0.25% acetic acid, (3) 0.02% chlorhexidine, and (4) 0.25% silver nitrate in patients with preexisting UTI. Two of the solutions (saline and acetic acid) had no effect on bacterial counts, but chlorhexidine and silver nitrate caused transient reductions in bacterial counts. Of the latter substances, silver nitrate achieved the greatest reductions in bacterial colony counts, but it was associated with a greater risk for side effects, including irritative lower urinary tract symptoms and discomfort. Although the study results demonstrate transient reduction in bacterial counts, data on long-term reduction or prevention of symptomatic UTI are not provided. Warren and colleagues45 determined the efficacy of intermittent use of an antibiotic solution (neomycin-polymixin) in a randomized clinical trial involving 187 subjects. Although no statistically significant differences in bacteriuria rates were found for either group, the lower urinary tract of subjects managed by intermittent irrigation were more likely to be colonized by antibiotic-resistant bacterial species. Of note, statistical analysis also revealed that increased disconnection of the catheter was associated with higher bacteriuria rates, leading the authors to advocate maintenance of a sealed drainage system rather than routine irrigation to reduce UTI risk in patients with indwelling catheters.

Question 8: Does the Frequency of Routine Catheter Changes Influence UTI Risk?

The guidelines differ on their recommendations concerning catheter change frequency. The Briggs' Institute best practice document2 advocates monthly catheter changes, whereas the CDC guidelines9 advise that arbitrary routine change schedules should be avoided. Three studies were identified that directly evaluated this issue. In a smaller study involving 17 subjects Priefer et al46 found that 86% of men in whom catheters were changed when a UTI or blockage occurred developed a symptomatic infection, whereas only 30% of those whose catheters were changed monthly and if UTI symptoms or obstruction developed experienced a symptomatic infection. White and Ragland47 retrospectively reviewed records of 106 patients managed by catheterization in a home care setting. The primary outcome of their study was UTI incidence, calculated as procedure-based incidence (number of infections per 100 catheters inserted) and person-based incidence (calculated as number of infections per 10,000 days using an indwelling catheter). After 6 weeks of catheterization, 15% of subjects whose catheter was changed every 2 weeks or less remained infection free as compared to 80% of those whose catheter was routinely changed every 4-6 weeks.

A third study was found that assessed the effect of catheter change immediately before antibiotic therapy in long-term care facility patients. Raz et al48 completed a randomized clinical trial of 54 nursing home residents managed by long-term catheterization. Subjects were randomized to undergo catheter replacement or no replacement before a clinical diagnosis of UTI. Clinical outcomes (reduction in polymicrobial colony counts, time to achieve afebrile status, and clinical status at 72 hours) were significantly better among subjects randomized to catheter change immediately before institution of antibiotic therapy.

Question 9: Does Placement of an Antiseptic (Antibacterial) Solution in the Drainage Bag Reduce UTI Risk?

The Brigg's Institute best practice dodument9 states that the addition of antiseptic solutions does not reduce UTI risk, but the CDC guidelines offer no specific recommendations related to this issue. Four studies were identified that addressed the efficacy of adding an antiseptic solution to the urinary drainage bag. One was located that evaluated the efficacy of silver ions in the bag and drainage tubing, and 1 was found that studied the effect of frequent bag changes.

Three studies (Thompson and coworkers,49 Sweet and associates,50 and Holliman and colleagues51) assessed the efficacy of adding hydrogen peroxide to the drainage bag. In their randomized clinical trial involving 668 patients, Thompson and coworkers49 found no advantage when hydrogen peroxide was added to the drainage bag. Although Sweet and associates50 found that hydrogen peroxide did reduce bacterial counts in the drainage bag itself, they found no differences in the incidence of bacteriuria or symptomatic UTI and ultimately reached the same conclusion as Thompson's group,49 that the addition of hydrogen peroxide to the drainage bag does not reduce UTI risk. In contrast to these findings, Holliman and colleagues51 completed a quasi-experimental study that lacked random assignment to treatment group. Outcome measures included cultures taken from the urine drainage bag, catheter-meatal junction, and intravesical urine. They found that patients managed by instillation of 30 mL of 3% hydrogen peroxide were less likely to develop a UTI and experienced more bacteriuria-free days than subjects managed without peroxide instillations.

Sujka et al52 completed a quasi-experimental study of 33 patients who required long-term indwelling catheterization after abdominoperineal resection for rectal cancer. Subjects were systematically assigned to undergo twice-weekly addition of Betadine vs no addition to the drainage bag. Although 33% of subjects managed by adding povidone-iodine to the drainage bag developed a UTI, 61% of those in the comparison group developed an infection. Based on these results, the authors recommend the routine addition of Betadine to the drainage bag of patients managed by an indwelling urinary catheter.

The fifth study evaluated the effectiveness of a catheter system containing a device that slowly releases silver ions onto the inner surface of the drainage tubing and collection bag. A randomized controlled trial compared 170 subjects using the new device or a closed system with standard drainage tubing and collection bag.53 No statistical differences were found in UTI rates.

A final study is included under this section because it addresses the issue of drainage bag management. Keerasuntonpong and associates54 evaluated the efficacy of frequent drainage bag changes on a group of 153 patients who were randomly assigned to undergo routine drainage bag replacement every 3 days or no change before catheter removal. Symptomatic UTI rates were similar in both groups, and the authors conclude that frequent bag changes do not reduce UTI risk.

Question 10: Does Separation of Patients With Catheter-Associated UTI Reduce the Risk of UTI in Other Patients Cared for in the Same Facility?

The CDC guidelines2 recommend separation of patients with a catheter-associated UTI from patients who are free from infection. A single study was located that addressed this potential preventive strategy. Maki et al55 observed that the principal risk factor for catheter-associated UTI with Serratia marcescens was sharing a room with a patient with a UTI and an indwelling catheter. The authors found evidence of bacterial colonization with Serratia m. on the hands of 50% of random surveys and speculated that personnel were more likely to wash their hands when changing rooms as compared to providing care to patients within the same room. A similar pattern of infection spread within a single facility was found with Pseudomonas species by McLeod,56 with Klebsiella by Orskov,57 and with Proteus, Klebsiella, Providence, and Pseudomonas species by Dutton and Ralston.58

Question 11: Do Staff Education and Quality Improvement Initiatives Reduce the Risk of Catheter-Associated UTI?

Both guidelines address the issue of staff education and its potential influence on UTI risk. The CDC guideline2 explicitly addresses staff education concerning insertion technique, management techniques, and prevention of potential complications, but associated references are not evidence-based studies. The Briggs Institute document states that there is insufficient evidence to provide specific recommendations concerning the effectiveness of staff education.9 Systematic literature review using MEDLINE and CINAHL databases from 1966 to November 2003 found 3 studies that specifically focused on this potential preventive strategy. French and colleagues59 designed and implemented a program to reduce nosocomial infections that included a new protocol for indwelling catheter management. These recommendations were based on "published recommendations," but their research report does not provide details concerning the substance of these guidelines. Nevertheless, they found that catheter-associated UTI rates fell from 6% to 2.2% after institution of specific catheter management guidelines designed to reduce UTI incidence.

Dumigan and associates60 developed a protocol that (1) allowed registered nurses to remove indwelling catheters without an explicit medical order as soon as it was no longer medically necessary and (2) ensured all cultures were accompanied by and based on results of urinalysis in a 500-bed community hospital. After introducing the protocol, catheter-associated occurrences fell 17% in the surgical intensive care unit (ICU), 29% in the medical ICU, and 45% in the coronary care ICU.

Goetz and coworkers61 provided professional nursing staff with quarterly reports of catheter-associated UTI for an 18-month data collection period and found that infection rates fell from a preintervention incidence of 32 infections per 1000 catheter-patient days to 17.4 days. They estimated the direct cost savings for this fall to equal $403,000 in 1999.

Key Points

1. There is a sufficient evidence base to recommend the following strategies for the prevention of catheter-associated UTI:

a. A silver impregnated catheter should be used for short-term catheterization in the female patient (Strength of Evidence: Level 1).

b. Maintenance of a closed drainage system reduces the risk of UTI in the short-term indwelling catheter (Strength of Evidence: Level 2).

c. Routine catheter changes, approximately every 4-6 weeks, are preferred to more frequent changes or changes only in response to obstruction or symptomatic infection among patients with long-term indwelling catheters (Strength of Evidence: Level 3).

d. Patients with a catheter-associated UTI may be placed in a separate room from others with indwelling catheters and absence of a UTI (Strength of Evidence: Level 3).

e. Informing staff of catheter-associated UTI incidence, combined with education about research or evidence-based policies, may reduce UTI frequency in a specific facility (Strength of Evidence: Level 3).

2. There is sufficient evidence to draw the following conclusions about the prevention of catheter-associated UTI:

a. Aseptic technique, including use of sterile gowns, drapes, and gloves; cleansing of the perineal area with an antiseptic soap; and employment of extended hand-washing techniques similar to those used for surgical preparation does not reduce the risk of developing bacteriuria within 72 hours of catheterization (Strength of Evidence: Level 2).

b. Routine meatal care does not reduce the incidence of bacteriuria, symptomatic UTI, or the time to onset of bacteruria for most patients (Strength of Evidence: Level 2).

c. The application of antimicrobial ointments or creams should be avoided because it may increase rather than diminish bacteriuria risk (Strength of Evidence: Level 1).

d. Routine irrigation with saline, antimicrobial, or antiseptic solutions does not reduce catheter-associated UTI risk (Strength of Evidence: Level 3).

e. The addition of hydrogen peroxide, silver sulfadiazine, or slow-releasing silver ions to the catheter drainage bag or drainage bag tubing does not reduce catheter-associated UTI risk (Strength of Evidence: Level 2).

f. Frequent bag changes do not reduce catheter-associated UTI-risk (Strength of Evidence: Level 1).

g. A one-way catheter valve does not reduce UTI risk in patients with long-term indwelling catheters (Strength of Evidence: Level 1).

3. There is insufficient evidence to conclude whether the following practices have any positive or negative influence on UTI risk in the catheterized patient.

a. Insertion of the smallest feasible catheter size.

b. Securing the catheter.

c. Regular addition of povidone-iodine to the catheter drainage bag.

Recommendations for Clinical Practice

1. A silver impregnated catheter should be selected for short-term catheterization.

2. Although selection of the smallest feasible catheter is believed to offer benefits, such as increased patient comfort and a reduced risk of urethral erosion, when worn long-term, its influence on UTI risk remains unknown.

3. Clean technique (washing the care providers hand, donning clean gloves, and cleansing apparent soiling from the perineal area) should be employed when inserting an indwelling catheter. Sterile technique may be used based on institutional policy, but the small body of evidence pertaining to this issue fails to reveal any support for the long-held belief that this more expensive technique provides clinically relevant benefit to patients.

4. The perineal area should be regularly cleaned regularly with water and an appropriate cleanser, but routine care protocols intended to reduce meatal bacterial flora and reduce the risk of ascending infection have proven ineffective or harmful and should be avoided.

5. Maintenance of a closed catheter drainage system reduces UTI risk in the patient with a short-term indwelling catheter. This strategy has not proved feasible for patients managed by long-term indwelling catheters.

6. Routine irrigation does not reduce UTI risk, and, therefore, it should not be employed for this purpose. Irrigation should be limited to its strongest indication, correction of catheter blockage or prevention of blockage in the patient with catheter encrustation.62

7. Routine catheter change schedules should avoid extreme frequency (every 2 weeks or more often) or infrequency (only when obstructed or a symptomatic UTI occurs). Routine changes every 4-6 weeks appear feasible for many patients managed by long-term indwelling catheters. A single study supports the current practice of changing the indwelling catheter immediately before initiating antibiotic therapy in the case of symptomatic catheter-associated UTI.

8. Placement of antiseptic solutions does not reduce UTI risk. A single study supports the use of povidone-iodine solution in the drainage bag after abdominoperineal resection, but this trial lacks randomization and no definitive conclusions concerning efficacy can be drawn.

9. Placement of patients with catheter-associated UTI in a room from those with an indwelling catheter and no infection may reduce the risk of spread within a single facility by encouraging hand washing between care encounters.

10. Quality improvement programs that include providing feedback to staff concerning nosocomial catheter-associated UTI rates and education concerning the insertion and management of indwelling catheters may reduce UTI incidence.

References