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00002800-200507000-0000500002800_2005_19_175_simpson_nosocomial_4miscellaneous< 54_0_8_1 >Clinical Nurse Specialist© 2005 Lippincott Williams & Wilkins, Inc.Volume 19(4)July/August 2005p 175–179Nosocomial UTI: Are We Treating the Catheter or the Patient?[legal and ethical dimensions of cns practice]SIMPSON, CHERIE MSN, RN, CNS; CLARK, ANGELA P. PhD, RN, CNS, FAAN, FAHASection Editor(s): Clark, Angela P. PhD, RN, CS, FAANUniversity of Texas at Austin School of Nursing.Corresponding author: Cherie Simpson, MSN, RN, CNS, The University of Texas at Austin School of Nursing, 1700 Red River, Austin, TX 78701 (e-mail: Centers for Disease Control and Prevention (CDC) estimates that 4 to 5 million patients in acute-care and extended-care facilities have urinary catheters inserted for some period of time.1 The CDC reports that the urinary tract is the most common site for nosocomial infection, and urinary tract infections (UTIs) represent greater than 40% of the institutionally acquired infections.1,2 While some patients with infections remain asymptomatic, catheter-associated urinary tract infections (CAUTIs) can lead to bloodstream infections and are associated with increased institutional death rates.1 These are devastating patient outcomes. Although many people with CAUTIs are asymptomatic, they are treated with antimicrobial drugs. This causes patients with CAUTIs to be the “largest institutional reservoir of nosocomial antibiotic-resistant pathogens.”1 Healthcare providers need to be judicious in deciding when to treat and be diligent in treating the offending microbe with the correct drug. Correctly identifying the organism is a laboratory function. Deciding when to collect the organism and implementing the procedure for collection is in the purview of many clinical nurse specialists (CNSs) who guide nursing practice in healthcare settings.In long-term-care facilities, elderly patients with chronic use of indwelling catheters can develop bacteriuria. A common standard for confirming bacteriuria is obtaining a positive urine culture with laboratory findings of greater than 100,000 colony-forming units of an isolate.3 A positive urine culture alone is not indicative of a UTI. Consideration of a patient's symptoms should be used in making the diagnosis.3 The CNS collaborates with other healthcare providers to determine the need to culture urine to identify the pathogen so that the appropriate medication can be prescribed to eliminate symptoms and avoid unnecessary or ineffective treatment.How the sample of urine for culture is obtained from an indwelling catheter can affect the laboratory results. Faulty protocols or handling errors can lead to contaminated urine samples, resulting in inaccurate laboratory reports or no results at all.4 Industry modifications to the catheter design have included a triple lumen system to permit urine sampling from a port without disruption of the closed system, thus eliminating sampling the urine from the drainage bag. There is the still the question, however, of whether or not the urine in the catheter lumen represents urine in the bladder.5 One suggested protocol to facilitate good sample collection is to require removal of the existing catheter and replacement with a new catheter prior to urine collection to ensure an accurate collection of the offending microbe.4,6 Does replacement have an impact on the patient's outcome by more accurately diagnosing an infection? Or, is this procedure placing the patient at greater risk by exposing him or her to another invasive technique? These are the main questions to be explored in this brief review of practice and research on sampling from indwelling catheters. In addition, we offer recommendations for a urine sampling procedure from an indwelling catheter of long-term duration when a UTI is suspected.CAUSE FOR CONCERNThe relevance in examining the protocol of urine sampling lies in the attempt to better diagnose and treat people with UTIs. Literature about the management of urinary catheters to prevent UTIs has focused on prevention, nonpharmacological interventions such as the merits of open versus closed systems, meatal care, system care, and types of materials available for use. Today, there is a growing discussion about the use of prophylactic antibiotics. One example is the Cochran review by Niël-Weise and van den Broek,7 which compares antibiotic prophylaxis with antibiotics used when clinically or microbiologically indicated. The evidence was not conclusive that prophylaxis treatment is better in preventing symptomatic bacteriuria. The authors noted that further research is needed to determine 3 important concerns: adverse effects, development of antibiotic resistance, and economic implications, before antibiotic prophylaxis to prevent UTIs can be recommended.These 3 concerns can also be applied to the current practice of treating patients for bacteriuria without a definitive diagnosis of a UTI. Bacteriuria alone does not cause altered mental status or a behavioral change in the elderly, but the tendency is to treat a positive urine culture in the presence of mental status change.3 Treatment with broad spectrum antibiotics is more costly than treatment with a more narrow spectrum antibiotic targeted to a specific microbe that has proven sensitivity, and overtreatment can lead to resistant bacteria.3 Economic and human resources are also wasted with urine cultures that are returned with contaminated samples or results that state “multiorganisms” and require additional cultures. Obtaining a culture and sensitivity test on a sample that accurately represents the microbe causing the infection is one way to avoid these issues. This emphasizes the need for developing best practices or protocols for how urine samples are obtained, especially in elderly patients who may have long-term catheter placement and present with nontraditional symptoms of UTI.EXISTING PROTOCOLSCurrent practice on the collection of urine for sampling from an indwelling catheter does not include the routine changing of the catheter prior to sampling. For example, Perry and Potter8 is widely used as a textbook instructing in clinical nursing skills. The procedure outlined for urine sampling includes using strict aseptic technique and to clamp the tubing for 30 minutes to allow fresh urine to collect in tubing rather than taking the sample from the bag. Common practice in long-term-care facilities is to use aseptic technique to withdraw urine with a syringe from the sampling port in the triple lumen catheter. This practice seems to be the standard, both nationally and internationally, as evidenced by policies from the Johns Hopkins Hospital9 and evidenced-based statements published by the NHS Quality Improvement group in Scotland.10 The CDC has published a guideline for urinary catheters that includes a section on specimen collection by simply cleansing the sampling port with a disinfectant prior to aspirating with a syringe.2 This procedure does not call for replacing the catheter before sampling. Some guidelines for care of patients with indwelling catheters never address the proper technique for sampling.11 Two articles that discuss evidence-based management of indwelling catheters did suggest that a sample for culture and sensitivity should be drawn from a newly inserted catheter.4,6 Neither of these articles had a direct reference for research that supported this practice.WHAT IS A BIOFILM?The theoretical basis behind the procedure of changing the catheter before taking the sample is the fact that bacterial colonization occurs rapidly in the bladder of a patient with an indwelling catheter by means of bacterial growth occurring along a biofilm formation on the lumen wall. The introduction of the catheter causes a “conditioning film” composed of proteins, electrolytes, and other organic material from the patient's urinary components and occurs within minutes of placement. The conditioning film then either blocks or provides receptors sites for bacterial adhesion.12 Infections can occur by extraluminal contamination from the patient's own flora or from the hands of a healthcare provider. Intraluminal contamination occurs by reflux of microorganisms from failure of a closed system or contamination of the urine in the bag.1 A biofilm forms either intraluminally or extraluminally, or both, allowing the organism(s) to grow and advance retrograde toward the bladder. The biofilm ascends by rapidly dividing bacteria along the catheter surface as well as planktonic (floating) cells that are sloughed from the matrix that moves ahead of the biofilm.13 An example of this rapid growth was reported by Horowitz and colleagues14 in a study of routine urine cultures at the time of catheter removal following a cesarean section. In the sample of 383 women, 1% of the urine cultures were positive, with growth of colonization greater than 100,000 units of a single organism per milliliter within 12 hours of catheter placement.The most common pathogen in nursing home patients without indwelling catheters is a monomicrobic (one organism) infection from Escherichia coli.15 Patients with CAUTI often have polymicrobic infections, which include Staphylococcus aureus and fungi such as Candida.15 Planktonic (floating) cells from these pathogens are continually sloughed off into the residual urine and “the bacterial biofilm adherent to the catheter cannot be appreciated by aspiration cultures of the planktonic bacteria.”13 For the bladder to become infected, bacteria have to invade and adhere to the bladder surface.13 Theoretically, the growth in the catheter may not represent the environment of the bladder. Removing the old catheter and replacing with a new sterile one creates an environment of sampling urine that is not influenced by an existing biofilm. Jones and colleagues16 captured images of actual biofilm formation in a silastic rubber catheter by resistant bacteria (methicillin-resistant staph aureus, [MRSA]) in a laboratory setting. The MRSA attached rapidly to the catheter surface, covering 10% of it after 2 hours and 60% of it after 48 hours.EVOLVING EVIDENCEThe intervention of replacing an existing indwelling catheter before urine sampling when a UTI is suspected is supported by research. Table 1 summarizes the aims, sample, design, findings, and recommendations of 5 studies that span from 1980 to the most recent published in January 2005. The strength of this collection is in the homogeneity of the samples being elderly and having chronic indwelling catheter use. Four of the 5 articles had samples that represent elderly and 3 of the 5 took place in long-term-care settings. The majority of the studies also addressed patients with long-term use of their indwelling catheter for greater than 30 days. With the exception of the first study, all of the studies involved comparing urine samples from existing catheters versus newly replaced catheters. None of the studies reported negative patient outcomes from replacing the catheter. The original study in 1980 by Bergovist et al5 established the fact that samples from the bladder have a different microbiology than samples taken from the catheter. The recommendation of sampling by suprapubic bladder aspiration may be more accurate but invasive. The other 4 studies compared, or included as part of the study, urine samples from existing catheters versus newly placed catheters. In all 4 studies, samples were taken before placement of a new catheter and after replacement. Consistently, there was a reduction in the different types of microbes isolated in the “replaced” specimen compared with the old catheter. Only 1 of the 4 studies did not recommend replacement before sampling because the researchers found little difference between the 2 highest ranking pathogens (K pneumoniae and E coli) in either the indwelling or replacement sample.18Table 1. Summary of Literature Review*More recent studies provide both clinical and financial outcomes to warrant changing the catheter prior to testing and treatment. The study by Raz et al19 provided evidence that clinical outcomes such as time to fever resolution and potential for symptomatic recurrence were reduced when the catheter was changed prior to treatment. Shah et al20 demonstrated that replacing the catheter before collecting urine samples for culture and sensitivity testing reduced the number of pathogens identified, reduced the number of toxic antimicrobials prescribed, and produced a cost savings in laboratory time in a population of spinal-cord-injury patients with chronic indwelling catheters. More important, for the long-term-care setting, Shah and colleagues20 found that replacing the catheter before sampling resulted in the use of less expensive and less potentially toxic antimicrobials, which reduced the potential costs of monitoring and negative patient side effects such as nephrotoxicity. Emr and Ryan4 reported cost-effective outcomes when a new practice of obtaining specimens from replacement catheters was implemented in a home health setting. Seventy percent fewer total specimens were collected because of a reduction in repeat sampling; 95% of the results were organism-specific and uncontaminated, and timely and appropriate urine infection treatment was implemented.IMPLICATIONS FOR PRACTICEBased on the evidence provided in the research reviewed and the positive outcomes experienced, replacing the catheter prior to urine sampling when a UTI is suspected can decrease risks and improve patient outcomes. The evidence suggests that this practice can reduce the treatment of bacteriuria without the presence of infection, reduce cost of antimicrobial treatment by targeting specific microbes with narrow spectrum antibiotics, and improve clinical outcomes. The implication for CNS practice in the long-term-care setting is to order a catheter change prior to urine sampling in patients when a UTI is suspected because of symptomatic presentation.Because this is not the standard practice currently in long-term-care facilities, the CNS can expect some resistance and the need for education for staff nurses and nursing administration. Future research is needed to duplicate the Shah20 study in a large-scale randomized controlled study of nursing home patients. Outcome variables should include clinical findings, such as time to resolution of fever, and economical measures, such as effect on nursing resource time. CNSs must be aware of evolving research, synthesize the findings, and adjust their practice accordingly for the best interest of their patients. Interventions that are effective in achieving nurse-sensitive outcomes should be incorporated into policies and guidelines.21AcknowledgmentsThe authors thank Fran Sonstein, RN, FNP, CNS, for asking the question.References1. Maki DG, Tambyah PA. Engineering out the risk of infection with urinary catheters. Emerg Infect Dis. 2001;7:1–13. Available at: . Accessed February 1, 2005. [Context Link]2. Wong ES. Guideline for prevention of catheter-associated urinary tract infections. CDC Issues in Healthc Settings. 2002. Available at: . Accessed February 1, 2005. [Context Link]3. Vance J. Diagnosing & managing urinary tract infections: myths, mysteries & realities. Caring for the Ages: A Monthly Newspaper for Long-Term Care Practitioner. 2002:3. Available at: . Accessed February 24, 2005. [Context Link]4. Emr K, Ryan R. Best practice for indwelling catheter in the home setting. Home Heatlhc Nurse. 2004;22:820–830. Available at: . Accessed February 26, 2004. [Context Link]5. Bergovist D, Brönnestam R, Hedelin H, Ståhl A. The relevance of urinary sampling methods in patients with indwelling foley catheters. Br J Urol. 1980;52:92–95. [Context Link]6. Smith JM. Indwelling catheter management: from habit-based to evidence-based practice. Ostomy Wound Manage. 2003;49:34–45. [Context Link]7. Niel-Weise BS, van den Broek PJ. Urinary catheter policies for long-term bladder drainage: review. Cochrane Collaboration. 2005;1:i–26. Available at: . Accessed February 13, 2005. [Context Link]8. Perry AG, Potter PA. Clinical Nursing Skills & Techniques. 5th ed. St. Louis: Mosby; 2002. [Context Link]9. Johns Hopkins Hospital. Urinary catheters. Interdiscipl Clin Pract Manual. Policy effective date October 31, 2004. Available at: . Accessed March 11, 2005. [Context Link]10. NHS. Best practice statement ∼ June 2004. Urinary catheterisation & catheter. NHS Qual Improv Scotland. Available at: . Accessed February 24, 2005. [Context Link]11. Madigan E, Neff DF. Care of patients with long-term indwelling urinary catheters. Online J Issues Nurs. 2003. Available at: . Accessed February 16, 2005. [Context Link]12. Beiko DT, Knudsen BE, Watterson JD, Cadieux PA, Reid G, Denstedt JD. Urinary tract biomaterials. J Urol. 2004;171:2438–2444. [CrossRef] [Full Text] [Medline Link] [Context Link]13. Nickel JC, Costerton JW, McLean RJC, Olson M. Bacterial biofilms: influence on the pathogenesis, diagnosis and treatment of urinary tract infections. J Antimicrob Chemother. 1994; 33(suppl A):31–41. [CrossRef] [Medline Link] [Context Link]14. Horowitz E, Yogev Y, Ben-Haroush A, Samra Z, Feldberg D, Kaplan B. Urine culture at removal of indwelling catheter after cesarean section. Int J Gynecol Obstet. 2003;85: 276–278. [CrossRef] [Medline Link] [Context Link]15. O'Donnell JA, Hofmann MT. Urinary tract infections: how to manage nursing home patients with or without chronic catheterization. Geriatrics. 2002;57:45–58. [Medline Link] [Context Link]16. Jones SM, Morgan M, Humphrey TJ, Lappin-Scott H. Effect of vancomycin and rifampicin on methicillin-resistant staphylococcus aureus biofilms. Lancet. 2001;357:40–41. [Context Link]17. Grahn D, Norman DC, White ML, Cantrell M, Yoshikawa TT. Validity of urinary catheter specimen for diagnosis of urinary tract infection in the elderly. Arch Intern Med. 1985;145:1858–1860.18. Tenney JH, Warren JW. Bacteriuria in women with long-term catheters: paired comparison of indwelling and replacement catheters. J Infect Dis. 1988;157:199–202. [CrossRef] [Medline Link] [Context Link]19. Raz R, Schiller D, Nicolle LE. Chronic indwelling catheter replacement before antimicrobial therapy for symptomatic urinary tract infection. J Urol. 2000;164:1254–1258. [CrossRef] [Full Text] [Medline Link] [Context Link]20. Shah PS, Cannon JP, Sullivan CL, Nemchausky B, Pachucki CT. Controlling antimicrobial use and decreasing microbiological laboratory tests for urinary tract infections in spinal-cord-injury patients with chronic indwelling catheters. Am J Health Syst Pharm. 2005;62:74–77. [Full Text] [Medline Link] [Context Link]21. National Association of Clinical Nurse Specialists. Statement on Clinical Nurse Specialist Practice and Education. 2nd ed. Harrisburg, Pa: NACNS; 2004. 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PhD, RN, CNS, FAAN, FAHAlegal and ethical dimensions of cns practice419