Drugs Aging (2014) 31:1–10 DOI 10.1007/s40266-013-0089-5
THERAPY IN PRACTICE
Catheter-Related Urinary Tract Infection: Practical Management in the Elderly Lindsay E. Nicolle
Published online: 28 November 2013 Springer International Publishing Switzerland 2013
Abstract From 5–10 % of elderly residents of long-term care facilities require chronic indwelling catheters for management of urine voiding. These residents are always bacteriuric, because of biofilm formation along the catheter, and experience increased morbidity associated with urinary tract infection. A wide variety of bacteria or yeast species are isolated. Occasional episodes of symptomatic infection may be accompanied by localizing genitourinary findings. However, when fever is present and there are no localizing findings, symptomatic infection is a diagnosis of exclusion. Many of these episodes are not from a urinary source, so critical clinical evaluation is always necessary. A urine specimen for culture should be obtained from patients with symptomatic infection prior to institution of antimicrobial therapy. When the catheter has been present for 2 weeks or longer, it should be replaced and the urine specimen collected through the new catheter. This provides a specimen of bladder urine without biofilm contamination, and catheter replacement also improves clinical outcomes. Treatment algorithms with a goal of limiting inappropriate treatment of asymptomatic bacteriuria have been developed. Empiric antimicrobial therapy should be avoided when possible. Guidelines for prevention of catheteracquired urinary infection should be followed. The most important of these is to avoid use of a urinary catheter whenever possible and, when there is no longer an indication for the catheter, to remove it promptly.
L. E. Nicolle (&) Department of Internal Medicine and Medical Microbiology, University of Manitoba, Health Sciences Centre, Room GG443, 820 Sherbrook Street, Winnipeg, MB R3A 1R9, Canada e-mail: [email protected]
1 Introduction From 5–10 % of elderly residents of long-term care facilities require chronic indwelling catheters for management of urinary voiding [1, 2]. An indwelling catheter is considered to be chronic or long term when it remains in situ for over 30 days [1, 2]. Some elderly residents in the community are also managed with a chronic indwelling catheter. Elderly individuals with chronic indwelling catheters have an increased risk of morbidity attributable to urinary tract infection. In addition, the diagnosis and some other aspects of management of symptomatic urinary infection differ when a chronic indwelling catheter is present. While this article focuses on the resident with a chronic indwelling catheter, many elderly patients admitted to acute care facilities undergo short-term urethral catheterization and, where appropriate, short-term catheterization is also addressed.
2 Epidemiology A recent prospective observational study described chronic indwelling catheter use in nursing home residents in one county in Sweden [3]. Chronic catheters were in place for 7 % of the nursing home population when the study was initiated, including 16 % of men and 3 % of women. Of these, 58 % had the catheter initially placed prior to nursing home admission, 18 % during a temporary stay in hospital, and 24 % while in the nursing home; 27 % had had the catheter in place for one to two years and 45 % for over two years. The most common reasons for catheterization were high residual urine/retention for men (86 %) and women (58 %). Incontinence was the indication for only 3 % of men and 14 % of women. At the end of one
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year, the catheter prevalence was 6.4 %. Outflow obstruction and catheter leakage were the most common reasons for unplanned catheter changes during the study year. Residents with chronic indwelling catheters always have a positive urine culture. Bacteriuria is usually asymptomatic, but residents with an indwelling catheter do experience excess morbidity attributed to symptomatic urinary infection [2]. The frequency of bacteremia in these residents is 3–30 times greater than elderly residents without an indwelling catheter, and fever from a presumed urinary source is 3–10 times more common [2, 4]. Local genitourinary morbidity attributed to use of a chronic indwelling catheter includes urolithiasis, urethritis, urethral abscess, prostatitis and epididymitis in men, and the noninfectious complications of urethral trauma, urethral strictures and limitation of mobility. Episodes of acute haematuria are more common in individuals with chronic indwelling catheters, presumably due to trauma or urolithiasis. Risk factors for the development of symptomatic infection in these universally bacteriuric residents are not well described [2]. Catheter obstruction or catheter trauma with mucosal bleeding may precipitate febrile urinary tract infection. Fever has been reported to occur at a rate of 8.1/ 100 patient days of catheter obstruction compared to 1.0/ 100 catheter days without obstruction [4]. However, predisposing factors are not identified for most episodes of symptomatic urinary tract infection. Residents of long term care facilities managed with chronic indwelling catheters have increased mortality compared to those without. The excess mortality is attributable to associated co-morbidities rather than the catheter [5]. Elderly residents with long term catheters are more functionally impaired, and functional status is an independent predictor of mortality in this population. Residents with a chronic indwelling catheter are also more likely to receive antimicrobial therapy [6] and to have resistant organisms isolated from urine cultures [7–9].
3 Microbiology 3.1 Catheter Biofilm The universal acquisition of bacteriuria when an indwelling urethral catheter remains in situ is primarily a consequence of biofilm formation along the catheter [10]. Biofilm is a material composed of bacteria within an extracellular glycopolysaccharide material produced by microorganisms as they grow along the catheter surface. The biofilm also incorporates urinary components such as Tamm-Horsfall protein and metal ions. Colonies of organisms growing within this material are protected from host defenses such as leukocytes or immunoglobulins, and access of many
L. E. Nicolle
antimicrobials to organisms growing in the biofilm is restricted. The process of biofilm formation is initiated immediately following insertion of an indwelling urethral catheter [2]. A conditioning layer of host proteins is laid down along the catheter which promotes adherence of bacteria. Biofilm usually starts at the urethral catheter junction on the exterior catheter surface, but may also develop on the interior surface of the catheter following bacterial contamination of urine along any part of the device. Organisms are shed from the biofilm into the urine and this facilitates progression of the biofilm along the catheter. The biofilm ascends the catheter and within several days will reach the urinary bladder. The acquisition of bacteriuria when an indwelling catheter is in situ is 3–7 % per day [1]. By 30 days, virtually all subjects are bacteriuric. The biofilm bacteriology is dynamic with loss of organisms and acquisition of new organisms at the continuing rate of 3–7 % per day [11]. 3.2 Microbiology A mature biofilm will have formed along most chronic indwelling catheters within 2 weeks. The microbiology is characterized by polymicrobial bacteriuria with 3–5 organisms isolated from urine specimens collected from the catheter. Organisms incorporated into the biofilm are not always present in bladder urine. A broad range of species may be isolated. Escherichia coli is common, as well as other Enterobacteriaceae and Gram negative organisms (Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Acinetobacter species), Gram positive organisms (Enterococcus species, coagulase negative staphylococci, group B streptococcus), and Candida species (Table 1). The most common bacterial strains isolated from 163 residents (126 men and 37 women) in Swedish long term care facilities in 2010 were Enterococcus faecalis and E. coli [8]. Proteus mirabilis was more common in subjects with a more prolonged duration of catheterization. Yeast species are more frequently isolated from individuals treated with broad spectrum antimicrobial therapy. Organisms isolated from the urine of subjects with indwelling urethral catheters have a higher prevalence of resistance to antimicrobials. When a catheterized patient receives antimicrobial therapy, organisms of increased antimicrobial resistance are often isolated from subsequent urine cultures [7, 8]. In the Swedish study, 16.9 % of E. coli isolated from residents with chronic catheters were ciprofloxacin resistant, compared to 7.9 % in a control group [8]. Important Gram negative resistant organisms such as extended spectrum beta lactamase (ESBL) producing Enterobacteriaceae are isolated more frequently in residents with catheters [7]. In one American region,
Catheter-Related Urinary Tract Infections in the Elderly Table 1 Range of bacterial species isolated from urine specimens collected through the catheter from residents with chronic indwelling catheters [8, 11, 12] Bacteria
Proportion of isolates (%)
Escherichia coli
10–37
Klebsiella spp.
3–21
Enterobacter spp. Proteus mirabilis
2.3–8.4 5.8–36
Morganella morganii
1.2–61
Providencia stuartii
50
Other Enterobacteriaceae
1.5–60
Pseudomonas aeruginosa
5–30
Other Gram negative
7–16
Enterococcus spp.
1–30
Staphylococcus aureus
4.7–6.5
Other Gram positive
5.0–20
residents of long term care facilities admitted to an acute care facility were 9.3 times more likely to have Klebsiella pneumoniae carbapenemase producing (KPC) organisms isolated if they had a chronic indwelling catheter than those without a catheter [9]. P. mirabilis is a common organism isolated from chronic indwelling catheters, and tends to persist for more prolonged periods than other species [2]. This is a urease producing organism. Urease reduces ammonia in the urine to create an alkaline environment which promotes precipitation of magnesium and calcium ions within the catheter biofilm. This material is termed a crystalline biofilm and is similar in composition to infection stones. Crystalline biofilm forms encrustations along the catheter, and is the most frequent cause of catheter obstruction. P. mirabilis is isolated from the urine of as many as 80 % of residents with obstructed chronic indwelling catheters. Other urease producing organisms such as K. pneumoniae, Morganella morganii and Providencia stuartii are also frequently isolated from biofilm, but are less likely to be associated with catheter obstruction.
4 Diagnosis 4.1 Clinical Presentation The most common clinical presentation of symptomatic urinary infection in residents managed with chronic indwelling catheters is fever with no localizing findings [4]. Localizing genitourinary signs or symptoms such as costovertebral angle pain or tenderness, acute hematuria, catheter obstruction or recent catheter trauma, when present, are helpful to confirm a urinary source for fever.
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However, these occur in a minority of episodes of fever attributed to urinary infection [4]. A substantial proportion of episodes of fever without localizing findings, however, are likely not from a urinary source. In a prospective study of fever episodes in residents of long term care facilities, symptomatic urinary tract infection was confirmed by measuring antibody response to uropathogens. Only 33 % of residents with a chronic indwelling catheter and fever without localizing findings had an antibody response consistent with a urinary source of infection [13]. In another prospective study of female residents with chronic catheters, Warren et al [4] reported that the majority of episodes of fever without a clear source were low grade and resolved without specific antimicrobial therapy. Fever was less than 38.3 C for 71 % of episodes and lasted for only one day in 58 %; 76 (78 %) of 98 febrile episodes resolved without specific therapy. Thus, other causes for fever must be considered, and urinary infection is always a diagnosis of exclusion in subjects with fever, a chronic indwelling catheter, and no localizing findings. 4.2 Laboratory diagnosis 4.2.1 Urine culture A urine specimen for culture should be collected from all elderly residents of long term care facilities with presumed symptomatic catheter acquired urinary tract infection prior to the initiation of antimicrobial therapy. Biofilm along the catheter surface contaminates the urine specimen when it is collected through the catheter. If the current indwelling catheter has been in situ 2 weeks or longer, it is recommended that the catheter be removed and replaced by a new catheter with the urine specimen for culture collected immediately through the replacement catheter and before initiating antimicrobial therapy [1]. The urine specimen collected following catheter replacement samples only bladder urine, so biofilm contamination does not compromise the microbiologic results. Catheter replacement prior to therapy is also associated with improved clinical outcomes including more rapid defervesence and decreased likelihood of early symptomatic relapse post-therapy [14]. For a short term catheter, the initial bacteriuria is usually with a single organism, most frequently E. coli. Multiple organisms are isolated from subjects with a chronic indwelling catheter. The laboratory requisition should identify the specimen as being from a patient with an indwelling catheter so appropriate work-up of multiple organisms will be performed. The quantitative diagnostic criteria for bacteriuria is C105 cfu/ml [1, 2]. Organisms isolated in lower quantitative counts from short or long term indwelling catheters usually reflect contamination of
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the urine by organisms present in the biofilm. Organisms \105 cfu/ml isolated from the replacement catheter when other strains are present at quantitative counts C105 cfu/ml tend not to persist, so antimicrobial treatment should likely be directed to organisms isolated at the higher quantitative counts [2].
developed for identification of infection in catheterized long term care facility residents have recently been published (Table 2), but are not yet validated [17].
4.2.2 Pyuria
5.1 Asymptomatic Bacteriuria
Pyuria is universal in residents with chronic indwelling catheters. The presence or degree of pyuria does not differentiate symptomatic from asymptomatic infection [2]. For patients with short term catheters, pyuria does not differentiate subjects with bacteriuria from those without bacteriuria, as the catheter itself may induce bladder inflammation and pyuria. Thus the presence of pyuria is not a helpful diagnostic test, and is not an indication for antimicrobial therapy.
Asymptomatic bacteriuria in a subject with an indwelling urethral catheter should not be treated with antimicrobial therapy [18]. A prospective, randomized comparative trial reported that treatment of asymptomatic bacteriuria in elderly long term care facility residents with a chronic indwelling catheter did not decrease the frequency of symptomatic infection, but was associated with an increased frequency of isolation of more resistant organisms [19]. In a prospective Swedish study of serial antimicrobial treatment of 24 long term care residents with chronic indwelling catheters, antimicrobial treatment did not decrease the prevalence of bacteriuria, while organisms of increasing resistance consistently emerged following treatment [20]. Antimicrobial resistance in residents of long term care facilities is an increasing concern given the widespread dissemination of ESBL and carbapenemase producing E. coli and K. pneumoniae [7, 9]. Other adverse effects of antimicrobial therapy include Clostridium difficile colitis and medication side effects. Thus, there are no benefits and some harms associated with treatment of asymptomatic bacteriuria. It follows that a urine specimen for culture should not be obtained from residents with longterm indwelling catheters unless symptomatic urinary infection is suspected.
4.3 Diagnostic Criteria Consensus guidelines have been developed for minimum criteria for initiation of antibiotics for urinary infection in long term care residents with chronic indwelling catheters [15]. These are one or more of: temperature greater than 37.9 C, new costovertebral angle tenderness, new onset rigors or new delirium. The Centers for Disease Control and Prevention (CDC) National Healthcare Safety Network has developed definitions for surveillance of symptomatic urinary infection in adult catheterized subjects [16] (Table 2). This definition, however, does not recognize the usual polymicrobial bacteriuria of individuals with a chronic indwelling catheter. Revised guidelines specifically
5 Antimicrobial Therapy
Table 2 Criteria for identification of symptomatic urinary tract infection for surveillance in adults with indwelling catheters CDC criteria [16]
Revised McGeer [17]
At least one of the following signs or symptoms with no other recognized cause:
At least one of the following:
Fever ([38C) Suprapubic tenderness Costovertebral pain and tenderness AND Urine culture C105 cfu/ml with no more than two species of microorganisms or Urine culture with C103 and\105 cfu/ml with no more than two species and: Positive urinalysis (dipstick of unspun urine or microscopy) Micro-organisms on Gram stain of unspun urine. cfu colony forming units
a. Fever, rigors, or new-onset hypotension with no alternate site b. Acute change in mental status or acute functional decline with no alternate diagnosis and leukocytosis c. New onset suprapubic pain or costovertebral pain or tenderness d. Purulent discharge from around the catheter or acute pain, swelling, or tenderness of the testes, epididymis, or prostate AND Urinary catheter specimen with C105 cfu/ml of any organism(s)
Catheter-Related Urinary Tract Infections in the Elderly
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5.2 Symptomatic Urinary Infection 5.2.1 Treatment Algorithms Algorithms for treatment of symptomatic urinary infection for patients with indwelling catheters have been developed [21, 22]. A goal of these is to limit antimicrobial treatment to patients with symptomatic infection, so initiation of antimicrobial therapy is recommended only for subjects with a high likelihood of urinary infection or with severe presentations of infection and no localizing findings. Consensus criteria for initiation of antimicrobial therapy were validated in a prospective randomized study of nursing home residents (Fig. 1), but only a few subjects enrolled in this study had an indwelling urinary catheter [21]. Trautner and colleagues [22] have developed an algorithm for treatment of catheterized patients which is currently being evaluated for use in acute and chronic hospital wards (Fig. 2). This algorithm suggests C103 cfu/ ml for cultures rather than C105 cfu/ml which is usually recommended. 5.2.2 Empiric Antimicrobial Therapy When a resident with a chronic catheter presents with fever and localizing genitourinary signs and symptoms, initiation
Fig. 1 Approach to treatment of symptomatic urinary infection in long-term care residents with indwelling catheters. Based on consensus criteria Loeb et al. [21]
•
of empiric antimicrobial therapy pending urine culture results is usually appropriate. If no localizing findings are identified but the clinical presentation is severe with signs and symptoms consistent with sepsis (acute rigors, hypotension, acute delirium), empiric antimicrobial treatment should be initiated promptly and include coverage appropriate for urinary tract infection as well as other potential sites of infection. Oral or parenteral antimicrobial therapy is selected depending on the clinical presentation. Parenteral therapy (intramuscular or intravenous) should be initiated for patients who are severely ill, vomiting, where there are concerns about absorption of oral therapy, or when there is a risk of infection with a resistant organism for which oral therapy is not available. The specific antimicrobial regimen should be determined considering patient tolerance and the presumed or likely infecting organisms based on prior cultures from the patient, recent antimicrobial therapy received by the resident, and the resistance characteristics of organisms known to be circulating in a given institution. When there are no localizing findings and the only symptom is fever, a reasonable approach if the resident is stable is observation without initiating antimicrobial therapy. A urine specimen for culture is only obtained if fever persists for more than 24 h without an alternate source becoming apparent. As many episodes of fever are low
Urine culture ≥ 105 cfu/ml or pending AND
•
Urinary catheter present AND
•
no alternate source
One or more of: •
new CVA (costovertebral) tenderness
•
shaking chills (rigors)
•
new onset delirium
•
fever (> 37.9°C or 1.5°C above baseline on 2 occasions over the
No
last 12 hr)
Yes No antibiotics Reassess
Initiate Empiric antibiotics
6 Fig. 2 Algorithm for initiation of antimicrobial therapy for catheter associated urinary infection [22] (used with permission, B.W. Trautner, S. Hysong, A.D. Naik)
L. E. Nicolle Fever Acute Hematuria Delirium Rigors Flank Pain
Start
Does the patient have any of CAUTI symptoms?
Pelvic Discomfort Urgency Frequency Dysuria Suprapubic Pain
NO
Do not send urine culture
YES
Work-up other cause
YES
Does a non-UTI diagnosis likely account for the symptoms
NO Send urine culture
Consider empiric antibiotics for CAUTI
Review urine culture results
Continue on other side
grade, of short duration, and resolve without antimicrobial therapy, this ‘‘wait and see’’ strategy is often appropriate [4]. If the fever resolves or an alternate source becomes apparent, antimicrobial therapy for urinary infection should not be initiated, even if a urine culture is positive. Many residents will have an alternate source such as respiratory virus infections or non-infectious causes. 5.3 Antimicrobial Regimens If the urine culture results are available prior to initiation of antimicrobial therapy, specific therapy targeted for the infecting organism(s) should be selected. There are many antimicrobials effective for treatment of urinary infection (Tables 3, 4). When empiric therapy is initiated, the antimicrobial regimen should be reassessed and modified to specific therapy once urine culture results become available, usually 48–72 h after specimen collection. If parenteral therapy was initiated, the antimicrobial should be changed to
oral therapy selected on the basis of the urine culture once the patient is clinically stable and can tolerate oral therapy. Parenteral antimicrobial therapy with ampicillin and an aminoglycoside provides good empiric coverage for treatment of urinary infection. Aminoglycoside therapy should be avoided, however, in individuals with renal impairment and should be reassessed when culture results become available. Alternate parenteral or oral antimicrobial therapy specific for the infecting organism can then usually be selected. If the aminoglycoside therapy is continued, there should be monitoring for aminoglycoside induced renal and eighth nerve toxicity. The third generation cephalosporins ceftriaxone and cefotaxime are appropriate for treatment of susceptible organisms. For some resistant organisms or when P. aeruginosa is isolated, ceftazidime and piperacillin/tazobactam may be preferred. When an ESBL producing organism is possible or confirmed a carbapenem (imipenem, meropenem, doripenem, ertapenem) should be initiated. The optimal antimicrobial
Catheter-Related Urinary Tract Infections in the Elderly Fig. 2 continued
7
Continued from other side
Review urine culture results
Were there more than 1000 organisms/ml?
NO
Was patient on antibiotics when urine culture sent?
NO
Re-evaluate case
YES YES
Is patient currently on antibiotics for CAUTI?
Base decision on symptoms prior to urine culture
NO
Are symptoms still present?
Stop empiric antibiotics given for CAUTI
NO
Do not start antibiotics
NO
Stop antibiotics given for CAUTI
YES Add antibiotics to treat the organism(s) isolated for 7-14 days
YES
Are symptoms still present?
YES
NO
Do antibiotics cover the organism isolated?
YES Continue antibiotics for 7 days
Do antibiotics cover the organism isolated?
NO
Change to appropriate antibiotics for 7-14 days
NO
Re-evaluate with attention to upper urinary tract or obstruction
YES
Original symptoms improving?
YES Continue antibiotics for 10-14 days
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L. E. Nicolle
Table 3 Oral antimicrobial regimens for the treatment of catheterassociated urinary tract infection
Table 5 Prevention strategies for catheter-acquired urinary tract infection in long-term care facility residents with indwelling catheters [16]
Agent
Dose
Comments
Amoxicillin
500 mg tid
Do not use empirically— high level resistance
Amoxicillin/ clavulanic acid
500 mg tid or 875 mg bid
Use for resistant organisms
Cephalexin
500 mg qid
Cefuroxime
250–500 mg bid
Cefixime
400 mg daily
Use for resistant organisms
Ciprofloxacin
500 mg bid
Norfloxacin
400 mg bid
Levofloxacin
500–750 mg daily
Avoid fluoroquinolones as first line therapy to limit resistance emergence
Trimethoprim/ sulfamethoxazole
160/800 mg bid
s Avoid trauma
Doxycycline
100 mg bid
s Identify obstruction early
Recommended • Avoid indwelling catheter whenever possible s Use only for restricted indications s Discontinue catheter as soon as feasible s Use alternate voiding methods j Intermittent catheter j Condom catheter (men) • Catheter management s Aseptic insertion* s Closed drainage* s Drainage bag below level of bladder* j Secure catheter
bid twice daily, qid four times daily, tid three times daily
• Replace catheter prior to antimicrobial treatment for urinary infection Not recommended
Table 4 Parenteral antimicrobial regimens for treatment of urinary infection in catheterized subjects: Agent
Dose (normal renal function)
Gentamicin ± ampicillin
5 mg/kg q24h ± 1 g q6h
Tobramycin ± ampicillin
5 mg/kg q24h ± 1 g q6h
Amikacin ± ampicillin
15–20 mg/kg q24h ± 1 g q6h
Cefazolin
1–2 g q6h
Cefotaxime
1–2 g q12h
Ceftriaxone
1–2 g q24h
Ceftazidime Ciprofloxacin
1 g q8–12h 400 mg q12h
Levofloxacin
500–750 mg q24h
Ertapenem
1 g q24h
Imipenem/cilastatin
500 mg q6h
Meropenem
500 mg q6h
Doripenem
500 mg q8h
Piperacillin/tazobactam
3.375 g q8h
qXh every X hours
therapy of urinary infection with carbapenemase producing organisms is not yet determined. If the infecting strain remains susceptible to an aminoglycoside, this is an effective option for therapy (Table 5). Ampicillin or co-trimoxazole (trimethoprim/sulfamethoxazole; TMP/SMX) are appropriate oral therapy for susceptible bacteria. Cephalosporins, fluoroquinolones, and amoxicillin/clavulanic acid may be effective for more resistant organisms. Fluoroquinolones should be avoided as first line therapy if possible because of concerns with resistance emergence. Oral therapy for more resistant organisms is directed by the susceptibility results, as strains are often resistant to multiple first line oral agents.
• Routine catheter change • Antimicrobial coated catheters • Periurethral antiseptic cleaning • Antiseptic in drainage bag * Effectiveness unknown for long term catheters
5.4 Duration of Therapy Subjects are usually afebrile by 72 h following institution of appropriate antimicrobial therapy [14]. If the indwelling catheter remains in situ, as short a duration of therapy as possible is preferred to limit antimicrobial pressure promoting emergence of resistant organisms. A duration of only 7 days of therapy is recommended when there is a prompt clinical response following initiation of therapy. If the clinical response is delayed, the patient should be reassessed and the diagnosis of urinary tract infection reconsidered. Defervesence of fever will also be delayed in residents who have not had catheter replacement prior to starting antimicrobial therapy and, possibly, in those with severe renal impairment. Occasionally, residents with delayed response to therapy or early symptomatic recurrence post therapy have underlying abnormalities such as urolithiasis or abscess which may require further investigation and management.
6 Prevention Evidence based guidelines provide recommendations for prevention of catheter-acquired urinary infection, but are primarily relevant for short-term catheters [1, 16]. The
Catheter-Related Urinary Tract Infections in the Elderly
most important intervention to prevent infection is not to use an indwelling catheter. There are only a limited number of valid indications for catheter use. These include output monitoring, selected surgical procedures, acute or chronic retention, end of life care, and to assist in healing a sacral pressure ulcer in an incontinent patient [16]. Chronic indwelling catheters should not be used for the management of incontinence alone. The use of an indwelling catheter to assist healing of a sacral pressure ulcer should be individualized, as not all these patients require a catheter. If an indwelling catheter is used, it should be removed as soon as the indications for use are no longer present. A resident with a chronic indwelling catheter should have the need for the catheter reappraised periodically so it is removed promptly, when possible. Alternatives to an indwelling catheter should be used where possible. For men, external condom catheters may be appropriate. Condom catheters are associated with an increased risk of bacteriuria and, possibly, symptomatic urinary tract infection, compared to the use of no device, but these complications appear to occur less frequently than in residents with chronic indwelling catheters. Intermittent catheterization is appropriate for some residents. This strategy has a lower risk for invasive urinary tract infection and other complications compared with use of a chronic indwelling catheter based on studies in spinal cord injured populations [1]. There is insufficient evidence to determine whether a suprapubic catheter is beneficial compared with an indwelling urethral catheter [23]. The suprapubic catheter requires surgical insertion and skilled health care personnel for replacement, so is not generally recommended. Residents with chronic indwelling catheters are always bacteriuric, and it is not clear what, if any, interventions effectively prevent acquisition of bacteriuria. Acquisition of bacteriuria may be delayed by strategies such as use of aseptic technique at insertion, maintaining closed drainage, and prevention of reflux from the drainage bag to the bladder, but the utility of any of these in preventing symptomatic infection in residents with chronic catheters has not been evaluated. There is no evidence to prefer any particular type of catheter or catheter material [24]. When residents use leg bags for drainage, recommendations for maintaining closed drainage are not relevant. If leg bags are used they should be cleaned and replaced in a standardized manner to limit contamination [25]. The most important prevention goal for residents with a chronic indwelling catheter is to minimize development of symptomatic infection. Recommendations for catheter management to prevent catheter trauma should be followed, such as securing the catheter, and catheter obstruction must be recognized early and corrected promptly. The most common cause of catheter obstruction
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is crystalline biofilm formation on the interior of the catheter associated with P. mirabilis bacteriuria [2]. There are no current interventions which specifically prevent this complication. The likelihood of development of catheter obstruction varies among individuals. Some residents have a high frequency of developing early or repeated obstruction. These individuals should be identified and monitored closely, with the catheter replaced promptly if there is any evidence of obstruction. Routine catheter replacement is not recommended [16]. Catheters should be replaced only if they are obstructed, bypassing, defective or otherwise not functioning, and prior to institution of antimicrobial therapy for the treatment of symptomatic urinary tract infection. Prophylactic antimicrobial therapy should not be given to prevent catheteracquired bacteriuria or symptomatic urinary infection. Antimicrobial therapy will not decrease the occurrence of bacteriuria or symptomatic infection, but is associated with isolation of organisms of increased resistance [23]. Other interventions such as acidification of the urine or use of methenamine mandelate and cranberry products are not effective [1, 26]. Antimicrobial coated catheters are not used for residents with chronic indwelling catheters as any effect of the antimicrobial catheter coating persists for only a few days following catheter insertion. Conflict of interest declare.
The author has no conflicts of interest to
References 1. Hooton TM, Bradley SE, Cardenas DD, et al. Diagnosis, prevention, and treatment of catheter-associated urinary tract infection in adults: 2009 International practice guidelines from the Infectious Diseases Society of America. Clin Infect Dis. 2010;50:625–63. 2. Nicolle LE. Urinary catheter infections. Infect Dis Clin North Am. 2012;26:13–28. 3. Jonsson K, E-Son Loft AL, Nasic S, Hedelin H. A prospective registration of catheter life and catheter interventions in patients with long-term indwelling catheters. Scand J Urol Nephrol. 2011;45:401–5. 4. Warren JW, Damron D, Tenney JH, et al. Fever, bacteremia, and death as complications of bacteriuria in women with long-term urethral catheters. J Infect Dis. 1987;155:1151–8. 5. Kunin CM, Chin QF, Chambers S. Morbidity and mortality associated with indwelling urinary catheters in elderly patients in a nursing home—confounding due to the presence of associated diseases. J Am Geriatr Soc. 1987;35:1001–6. 6. Phillips CD, Adepoju O, Stone N, et al. Asymptomatic bacteriuria, antibiotic use, and suspected urinary tract infections in four nursing homes. BMC Geriatr. 2012;12:73–80. 7. Tinelli M, Cataldo MA, Mantengoli E, et al. Epidemiology and genetic characteristics of extended-spectrum b-lactamase-producing Gram-negative bacteria causing urinary tract infections in long-term care facilities. J Antimicrob Chemother. 2012;67:2982–7.
10 8. Jonsson K, Claesson BEB, Hedelin H. Urine cultures from indwelling bladder catheters in nursing home patients: a point prevalence study in a Swedish county. Scand J Urol Nephrol. 2011;45:264–5. 9. Prabaker K, Lin MY, McNally M, et al. Transfer from highacuity long term care facilities is associated with carriage of Klebsiella pneumoniae carbapenemase-producing Enterobacteriaceae: a multihospital study. Infect Control Hosp Epidemiol. 2012;33:1193–9. 10. Stickler DJ. Bacterial biofilms in patients with indwelling urinary catheters. Nat Clin Pract Urol. 2008;5:598–608. 11. Warren JW, Tenney JH, Hoopes JM, et al. A prospective microbiologic study of bacteriuria in patients with chronic indwelling urethral catheters. J Infect Dis. 1982;146:719–23. 12. Nicolle LE. The chronic indwelling catheter and urinary infection in long term care facility residents. Infect Control Hosp Epidemiol. 2001;22:316–21. 13. Orr PH, Nicolle LE, Duckworth H, et al. Febrile urinary infection in the institutionalized elderly. Am J Med. 1996;100:71–7. 14. Raz R, Schiller D, Nicolle LE. Chronic indwelling catheter replacement before antimicrobial therapy for symptomatic urinary tract infection. J Urol. 2000;164:1254–8. 15. Loeb M, Bentley DW, Bradley S, et al. Development of minimum criteria for the initiation of antibiotics in residents of long term care facilities: results of a consensus conference. Infect Control Hosp Epidemiol. 2001;22:120–4. 16. Gould C, Umscheid CA, Agarwal RK, et al. Guideline for prevention of catheter-associated urinary tract infections 2009. http://www.cdc.gov/hicpac/. 17. Stone ND, Ashraf MS, Calder J, et al. Surveillance definitions of infections in long term care facilities: revisiting the McGeer criteria. Infect Control Hosp Epidemiol. 2012;10:965–77.
L. E. Nicolle 18. Nicolle LE, Bradley S, Colgan R, et al. IDSA guideline for the diagnosis and treatment of asymptomatic bacteriuria in adults. Clin Infect Dis. 2005;40:643–54. 19. Warren JW, Anthony WC, Hoopes JM, et al. Cephalexin for susceptible bacteriuria in afebrile, long-term catheterized patients. JAMA. 1982;248:454–8. 20. Alling B, Brandeberg A, Seeberg S, et al. Effect of consecutive antibacterial therapy on bacteriuria in hospitalized geriatric patients. Scand J Infect Dis. 1975;7:201–7. 21. Loeb M, Brazil K, Lohfeld L, et al. Effect of a multifaceted intervention on number of antimicrobial prescriptions for suspected urinary tract infections in residents of nursing homes: cluster randomized controlled trial. BMJ. 2005;331:669–72. 22. Trautner BW, Kelly PA, Petersen N, et al. A hospital-site controlled intervention using audit and feedback to implement guidelines concerning inappropriate treatment of catheter-associated asymptomatic bacteriuria. Implement Sci. 2011;6:41. 23. Niel-Weise BS, van den Brock PJ, da Silva EMK et al. Urinary catheter policies for long-term bladder drainage. Cochrane Database Syst Rev. 2012;(8):CD004201. doi:10.1002/14651858. CD004201.pub3. 24. Jahn P, Beutner K, Langer G. Types of indwelling urinary catheters for long-term bladder drainage in adults. Cochrane Database Syst Rev. 2012;(10):CD004997. doi:10.1002/ 14651858.CD004997.pub3. 25. Smith PW, Bennett G, Bradley S, et al. SHEA/APIC guideline: infection prevention and control in the long term care facility. Infect Control Hosp Epidemiol. 2008;29:785–814. 26. Lee BS, Bhuta T, Simpson JM et al. Methenamine hippurate for preventing urinary tract infections. Cochrane Database Syst Rev. 2012;(10):CD003265. doi:10.1002/14651858.CD003265.pub3.
THERAPY IN PRACTICE
Catheter-Related Urinary Tract Infection: Practical Management in the Elderly Lindsay E. Nicolle
Published online: 28 November 2013 Springer International Publishing Switzerland 2013
Abstract From 5–10 % of elderly residents of long-term care facilities require chronic indwelling catheters for management of urine voiding. These residents are always bacteriuric, because of biofilm formation along the catheter, and experience increased morbidity associated with urinary tract infection. A wide variety of bacteria or yeast species are isolated. Occasional episodes of symptomatic infection may be accompanied by localizing genitourinary findings. However, when fever is present and there are no localizing findings, symptomatic infection is a diagnosis of exclusion. Many of these episodes are not from a urinary source, so critical clinical evaluation is always necessary. A urine specimen for culture should be obtained from patients with symptomatic infection prior to institution of antimicrobial therapy. When the catheter has been present for 2 weeks or longer, it should be replaced and the urine specimen collected through the new catheter. This provides a specimen of bladder urine without biofilm contamination, and catheter replacement also improves clinical outcomes. Treatment algorithms with a goal of limiting inappropriate treatment of asymptomatic bacteriuria have been developed. Empiric antimicrobial therapy should be avoided when possible. Guidelines for prevention of catheteracquired urinary infection should be followed. The most important of these is to avoid use of a urinary catheter whenever possible and, when there is no longer an indication for the catheter, to remove it promptly.
L. E. Nicolle (&) Department of Internal Medicine and Medical Microbiology, University of Manitoba, Health Sciences Centre, Room GG443, 820 Sherbrook Street, Winnipeg, MB R3A 1R9, Canada e-mail: [email protected]
1 Introduction From 5–10 % of elderly residents of long-term care facilities require chronic indwelling catheters for management of urinary voiding [1, 2]. An indwelling catheter is considered to be chronic or long term when it remains in situ for over 30 days [1, 2]. Some elderly residents in the community are also managed with a chronic indwelling catheter. Elderly individuals with chronic indwelling catheters have an increased risk of morbidity attributable to urinary tract infection. In addition, the diagnosis and some other aspects of management of symptomatic urinary infection differ when a chronic indwelling catheter is present. While this article focuses on the resident with a chronic indwelling catheter, many elderly patients admitted to acute care facilities undergo short-term urethral catheterization and, where appropriate, short-term catheterization is also addressed.
2 Epidemiology A recent prospective observational study described chronic indwelling catheter use in nursing home residents in one county in Sweden [3]. Chronic catheters were in place for 7 % of the nursing home population when the study was initiated, including 16 % of men and 3 % of women. Of these, 58 % had the catheter initially placed prior to nursing home admission, 18 % during a temporary stay in hospital, and 24 % while in the nursing home; 27 % had had the catheter in place for one to two years and 45 % for over two years. The most common reasons for catheterization were high residual urine/retention for men (86 %) and women (58 %). Incontinence was the indication for only 3 % of men and 14 % of women. At the end of one
2
year, the catheter prevalence was 6.4 %. Outflow obstruction and catheter leakage were the most common reasons for unplanned catheter changes during the study year. Residents with chronic indwelling catheters always have a positive urine culture. Bacteriuria is usually asymptomatic, but residents with an indwelling catheter do experience excess morbidity attributed to symptomatic urinary infection [2]. The frequency of bacteremia in these residents is 3–30 times greater than elderly residents without an indwelling catheter, and fever from a presumed urinary source is 3–10 times more common [2, 4]. Local genitourinary morbidity attributed to use of a chronic indwelling catheter includes urolithiasis, urethritis, urethral abscess, prostatitis and epididymitis in men, and the noninfectious complications of urethral trauma, urethral strictures and limitation of mobility. Episodes of acute haematuria are more common in individuals with chronic indwelling catheters, presumably due to trauma or urolithiasis. Risk factors for the development of symptomatic infection in these universally bacteriuric residents are not well described [2]. Catheter obstruction or catheter trauma with mucosal bleeding may precipitate febrile urinary tract infection. Fever has been reported to occur at a rate of 8.1/ 100 patient days of catheter obstruction compared to 1.0/ 100 catheter days without obstruction [4]. However, predisposing factors are not identified for most episodes of symptomatic urinary tract infection. Residents of long term care facilities managed with chronic indwelling catheters have increased mortality compared to those without. The excess mortality is attributable to associated co-morbidities rather than the catheter [5]. Elderly residents with long term catheters are more functionally impaired, and functional status is an independent predictor of mortality in this population. Residents with a chronic indwelling catheter are also more likely to receive antimicrobial therapy [6] and to have resistant organisms isolated from urine cultures [7–9].
3 Microbiology 3.1 Catheter Biofilm The universal acquisition of bacteriuria when an indwelling urethral catheter remains in situ is primarily a consequence of biofilm formation along the catheter [10]. Biofilm is a material composed of bacteria within an extracellular glycopolysaccharide material produced by microorganisms as they grow along the catheter surface. The biofilm also incorporates urinary components such as Tamm-Horsfall protein and metal ions. Colonies of organisms growing within this material are protected from host defenses such as leukocytes or immunoglobulins, and access of many
L. E. Nicolle
antimicrobials to organisms growing in the biofilm is restricted. The process of biofilm formation is initiated immediately following insertion of an indwelling urethral catheter [2]. A conditioning layer of host proteins is laid down along the catheter which promotes adherence of bacteria. Biofilm usually starts at the urethral catheter junction on the exterior catheter surface, but may also develop on the interior surface of the catheter following bacterial contamination of urine along any part of the device. Organisms are shed from the biofilm into the urine and this facilitates progression of the biofilm along the catheter. The biofilm ascends the catheter and within several days will reach the urinary bladder. The acquisition of bacteriuria when an indwelling catheter is in situ is 3–7 % per day [1]. By 30 days, virtually all subjects are bacteriuric. The biofilm bacteriology is dynamic with loss of organisms and acquisition of new organisms at the continuing rate of 3–7 % per day [11]. 3.2 Microbiology A mature biofilm will have formed along most chronic indwelling catheters within 2 weeks. The microbiology is characterized by polymicrobial bacteriuria with 3–5 organisms isolated from urine specimens collected from the catheter. Organisms incorporated into the biofilm are not always present in bladder urine. A broad range of species may be isolated. Escherichia coli is common, as well as other Enterobacteriaceae and Gram negative organisms (Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Acinetobacter species), Gram positive organisms (Enterococcus species, coagulase negative staphylococci, group B streptococcus), and Candida species (Table 1). The most common bacterial strains isolated from 163 residents (126 men and 37 women) in Swedish long term care facilities in 2010 were Enterococcus faecalis and E. coli [8]. Proteus mirabilis was more common in subjects with a more prolonged duration of catheterization. Yeast species are more frequently isolated from individuals treated with broad spectrum antimicrobial therapy. Organisms isolated from the urine of subjects with indwelling urethral catheters have a higher prevalence of resistance to antimicrobials. When a catheterized patient receives antimicrobial therapy, organisms of increased antimicrobial resistance are often isolated from subsequent urine cultures [7, 8]. In the Swedish study, 16.9 % of E. coli isolated from residents with chronic catheters were ciprofloxacin resistant, compared to 7.9 % in a control group [8]. Important Gram negative resistant organisms such as extended spectrum beta lactamase (ESBL) producing Enterobacteriaceae are isolated more frequently in residents with catheters [7]. In one American region,
Catheter-Related Urinary Tract Infections in the Elderly Table 1 Range of bacterial species isolated from urine specimens collected through the catheter from residents with chronic indwelling catheters [8, 11, 12] Bacteria
Proportion of isolates (%)
Escherichia coli
10–37
Klebsiella spp.
3–21
Enterobacter spp. Proteus mirabilis
2.3–8.4 5.8–36
Morganella morganii
1.2–61
Providencia stuartii
50
Other Enterobacteriaceae
1.5–60
Pseudomonas aeruginosa
5–30
Other Gram negative
7–16
Enterococcus spp.
1–30
Staphylococcus aureus
4.7–6.5
Other Gram positive
5.0–20
residents of long term care facilities admitted to an acute care facility were 9.3 times more likely to have Klebsiella pneumoniae carbapenemase producing (KPC) organisms isolated if they had a chronic indwelling catheter than those without a catheter [9]. P. mirabilis is a common organism isolated from chronic indwelling catheters, and tends to persist for more prolonged periods than other species [2]. This is a urease producing organism. Urease reduces ammonia in the urine to create an alkaline environment which promotes precipitation of magnesium and calcium ions within the catheter biofilm. This material is termed a crystalline biofilm and is similar in composition to infection stones. Crystalline biofilm forms encrustations along the catheter, and is the most frequent cause of catheter obstruction. P. mirabilis is isolated from the urine of as many as 80 % of residents with obstructed chronic indwelling catheters. Other urease producing organisms such as K. pneumoniae, Morganella morganii and Providencia stuartii are also frequently isolated from biofilm, but are less likely to be associated with catheter obstruction.
4 Diagnosis 4.1 Clinical Presentation The most common clinical presentation of symptomatic urinary infection in residents managed with chronic indwelling catheters is fever with no localizing findings [4]. Localizing genitourinary signs or symptoms such as costovertebral angle pain or tenderness, acute hematuria, catheter obstruction or recent catheter trauma, when present, are helpful to confirm a urinary source for fever.
3
However, these occur in a minority of episodes of fever attributed to urinary infection [4]. A substantial proportion of episodes of fever without localizing findings, however, are likely not from a urinary source. In a prospective study of fever episodes in residents of long term care facilities, symptomatic urinary tract infection was confirmed by measuring antibody response to uropathogens. Only 33 % of residents with a chronic indwelling catheter and fever without localizing findings had an antibody response consistent with a urinary source of infection [13]. In another prospective study of female residents with chronic catheters, Warren et al [4] reported that the majority of episodes of fever without a clear source were low grade and resolved without specific antimicrobial therapy. Fever was less than 38.3 C for 71 % of episodes and lasted for only one day in 58 %; 76 (78 %) of 98 febrile episodes resolved without specific therapy. Thus, other causes for fever must be considered, and urinary infection is always a diagnosis of exclusion in subjects with fever, a chronic indwelling catheter, and no localizing findings. 4.2 Laboratory diagnosis 4.2.1 Urine culture A urine specimen for culture should be collected from all elderly residents of long term care facilities with presumed symptomatic catheter acquired urinary tract infection prior to the initiation of antimicrobial therapy. Biofilm along the catheter surface contaminates the urine specimen when it is collected through the catheter. If the current indwelling catheter has been in situ 2 weeks or longer, it is recommended that the catheter be removed and replaced by a new catheter with the urine specimen for culture collected immediately through the replacement catheter and before initiating antimicrobial therapy [1]. The urine specimen collected following catheter replacement samples only bladder urine, so biofilm contamination does not compromise the microbiologic results. Catheter replacement prior to therapy is also associated with improved clinical outcomes including more rapid defervesence and decreased likelihood of early symptomatic relapse post-therapy [14]. For a short term catheter, the initial bacteriuria is usually with a single organism, most frequently E. coli. Multiple organisms are isolated from subjects with a chronic indwelling catheter. The laboratory requisition should identify the specimen as being from a patient with an indwelling catheter so appropriate work-up of multiple organisms will be performed. The quantitative diagnostic criteria for bacteriuria is C105 cfu/ml [1, 2]. Organisms isolated in lower quantitative counts from short or long term indwelling catheters usually reflect contamination of
4
L. E. Nicolle
the urine by organisms present in the biofilm. Organisms \105 cfu/ml isolated from the replacement catheter when other strains are present at quantitative counts C105 cfu/ml tend not to persist, so antimicrobial treatment should likely be directed to organisms isolated at the higher quantitative counts [2].
developed for identification of infection in catheterized long term care facility residents have recently been published (Table 2), but are not yet validated [17].
4.2.2 Pyuria
5.1 Asymptomatic Bacteriuria
Pyuria is universal in residents with chronic indwelling catheters. The presence or degree of pyuria does not differentiate symptomatic from asymptomatic infection [2]. For patients with short term catheters, pyuria does not differentiate subjects with bacteriuria from those without bacteriuria, as the catheter itself may induce bladder inflammation and pyuria. Thus the presence of pyuria is not a helpful diagnostic test, and is not an indication for antimicrobial therapy.
Asymptomatic bacteriuria in a subject with an indwelling urethral catheter should not be treated with antimicrobial therapy [18]. A prospective, randomized comparative trial reported that treatment of asymptomatic bacteriuria in elderly long term care facility residents with a chronic indwelling catheter did not decrease the frequency of symptomatic infection, but was associated with an increased frequency of isolation of more resistant organisms [19]. In a prospective Swedish study of serial antimicrobial treatment of 24 long term care residents with chronic indwelling catheters, antimicrobial treatment did not decrease the prevalence of bacteriuria, while organisms of increasing resistance consistently emerged following treatment [20]. Antimicrobial resistance in residents of long term care facilities is an increasing concern given the widespread dissemination of ESBL and carbapenemase producing E. coli and K. pneumoniae [7, 9]. Other adverse effects of antimicrobial therapy include Clostridium difficile colitis and medication side effects. Thus, there are no benefits and some harms associated with treatment of asymptomatic bacteriuria. It follows that a urine specimen for culture should not be obtained from residents with longterm indwelling catheters unless symptomatic urinary infection is suspected.
4.3 Diagnostic Criteria Consensus guidelines have been developed for minimum criteria for initiation of antibiotics for urinary infection in long term care residents with chronic indwelling catheters [15]. These are one or more of: temperature greater than 37.9 C, new costovertebral angle tenderness, new onset rigors or new delirium. The Centers for Disease Control and Prevention (CDC) National Healthcare Safety Network has developed definitions for surveillance of symptomatic urinary infection in adult catheterized subjects [16] (Table 2). This definition, however, does not recognize the usual polymicrobial bacteriuria of individuals with a chronic indwelling catheter. Revised guidelines specifically
5 Antimicrobial Therapy
Table 2 Criteria for identification of symptomatic urinary tract infection for surveillance in adults with indwelling catheters CDC criteria [16]
Revised McGeer [17]
At least one of the following signs or symptoms with no other recognized cause:
At least one of the following:
Fever ([38C) Suprapubic tenderness Costovertebral pain and tenderness AND Urine culture C105 cfu/ml with no more than two species of microorganisms or Urine culture with C103 and\105 cfu/ml with no more than two species and: Positive urinalysis (dipstick of unspun urine or microscopy) Micro-organisms on Gram stain of unspun urine. cfu colony forming units
a. Fever, rigors, or new-onset hypotension with no alternate site b. Acute change in mental status or acute functional decline with no alternate diagnosis and leukocytosis c. New onset suprapubic pain or costovertebral pain or tenderness d. Purulent discharge from around the catheter or acute pain, swelling, or tenderness of the testes, epididymis, or prostate AND Urinary catheter specimen with C105 cfu/ml of any organism(s)
Catheter-Related Urinary Tract Infections in the Elderly
5
5.2 Symptomatic Urinary Infection 5.2.1 Treatment Algorithms Algorithms for treatment of symptomatic urinary infection for patients with indwelling catheters have been developed [21, 22]. A goal of these is to limit antimicrobial treatment to patients with symptomatic infection, so initiation of antimicrobial therapy is recommended only for subjects with a high likelihood of urinary infection or with severe presentations of infection and no localizing findings. Consensus criteria for initiation of antimicrobial therapy were validated in a prospective randomized study of nursing home residents (Fig. 1), but only a few subjects enrolled in this study had an indwelling urinary catheter [21]. Trautner and colleagues [22] have developed an algorithm for treatment of catheterized patients which is currently being evaluated for use in acute and chronic hospital wards (Fig. 2). This algorithm suggests C103 cfu/ ml for cultures rather than C105 cfu/ml which is usually recommended. 5.2.2 Empiric Antimicrobial Therapy When a resident with a chronic catheter presents with fever and localizing genitourinary signs and symptoms, initiation
Fig. 1 Approach to treatment of symptomatic urinary infection in long-term care residents with indwelling catheters. Based on consensus criteria Loeb et al. [21]
•
of empiric antimicrobial therapy pending urine culture results is usually appropriate. If no localizing findings are identified but the clinical presentation is severe with signs and symptoms consistent with sepsis (acute rigors, hypotension, acute delirium), empiric antimicrobial treatment should be initiated promptly and include coverage appropriate for urinary tract infection as well as other potential sites of infection. Oral or parenteral antimicrobial therapy is selected depending on the clinical presentation. Parenteral therapy (intramuscular or intravenous) should be initiated for patients who are severely ill, vomiting, where there are concerns about absorption of oral therapy, or when there is a risk of infection with a resistant organism for which oral therapy is not available. The specific antimicrobial regimen should be determined considering patient tolerance and the presumed or likely infecting organisms based on prior cultures from the patient, recent antimicrobial therapy received by the resident, and the resistance characteristics of organisms known to be circulating in a given institution. When there are no localizing findings and the only symptom is fever, a reasonable approach if the resident is stable is observation without initiating antimicrobial therapy. A urine specimen for culture is only obtained if fever persists for more than 24 h without an alternate source becoming apparent. As many episodes of fever are low
Urine culture ≥ 105 cfu/ml or pending AND
•
Urinary catheter present AND
•
no alternate source
One or more of: •
new CVA (costovertebral) tenderness
•
shaking chills (rigors)
•
new onset delirium
•
fever (> 37.9°C or 1.5°C above baseline on 2 occasions over the
No
last 12 hr)
Yes No antibiotics Reassess
Initiate Empiric antibiotics
6 Fig. 2 Algorithm for initiation of antimicrobial therapy for catheter associated urinary infection [22] (used with permission, B.W. Trautner, S. Hysong, A.D. Naik)
L. E. Nicolle Fever Acute Hematuria Delirium Rigors Flank Pain
Start
Does the patient have any of CAUTI symptoms?
Pelvic Discomfort Urgency Frequency Dysuria Suprapubic Pain
NO
Do not send urine culture
YES
Work-up other cause
YES
Does a non-UTI diagnosis likely account for the symptoms
NO Send urine culture
Consider empiric antibiotics for CAUTI
Review urine culture results
Continue on other side
grade, of short duration, and resolve without antimicrobial therapy, this ‘‘wait and see’’ strategy is often appropriate [4]. If the fever resolves or an alternate source becomes apparent, antimicrobial therapy for urinary infection should not be initiated, even if a urine culture is positive. Many residents will have an alternate source such as respiratory virus infections or non-infectious causes. 5.3 Antimicrobial Regimens If the urine culture results are available prior to initiation of antimicrobial therapy, specific therapy targeted for the infecting organism(s) should be selected. There are many antimicrobials effective for treatment of urinary infection (Tables 3, 4). When empiric therapy is initiated, the antimicrobial regimen should be reassessed and modified to specific therapy once urine culture results become available, usually 48–72 h after specimen collection. If parenteral therapy was initiated, the antimicrobial should be changed to
oral therapy selected on the basis of the urine culture once the patient is clinically stable and can tolerate oral therapy. Parenteral antimicrobial therapy with ampicillin and an aminoglycoside provides good empiric coverage for treatment of urinary infection. Aminoglycoside therapy should be avoided, however, in individuals with renal impairment and should be reassessed when culture results become available. Alternate parenteral or oral antimicrobial therapy specific for the infecting organism can then usually be selected. If the aminoglycoside therapy is continued, there should be monitoring for aminoglycoside induced renal and eighth nerve toxicity. The third generation cephalosporins ceftriaxone and cefotaxime are appropriate for treatment of susceptible organisms. For some resistant organisms or when P. aeruginosa is isolated, ceftazidime and piperacillin/tazobactam may be preferred. When an ESBL producing organism is possible or confirmed a carbapenem (imipenem, meropenem, doripenem, ertapenem) should be initiated. The optimal antimicrobial
Catheter-Related Urinary Tract Infections in the Elderly Fig. 2 continued
7
Continued from other side
Review urine culture results
Were there more than 1000 organisms/ml?
NO
Was patient on antibiotics when urine culture sent?
NO
Re-evaluate case
YES YES
Is patient currently on antibiotics for CAUTI?
Base decision on symptoms prior to urine culture
NO
Are symptoms still present?
Stop empiric antibiotics given for CAUTI
NO
Do not start antibiotics
NO
Stop antibiotics given for CAUTI
YES Add antibiotics to treat the organism(s) isolated for 7-14 days
YES
Are symptoms still present?
YES
NO
Do antibiotics cover the organism isolated?
YES Continue antibiotics for 7 days
Do antibiotics cover the organism isolated?
NO
Change to appropriate antibiotics for 7-14 days
NO
Re-evaluate with attention to upper urinary tract or obstruction
YES
Original symptoms improving?
YES Continue antibiotics for 10-14 days
8
L. E. Nicolle
Table 3 Oral antimicrobial regimens for the treatment of catheterassociated urinary tract infection
Table 5 Prevention strategies for catheter-acquired urinary tract infection in long-term care facility residents with indwelling catheters [16]
Agent
Dose
Comments
Amoxicillin
500 mg tid
Do not use empirically— high level resistance
Amoxicillin/ clavulanic acid
500 mg tid or 875 mg bid
Use for resistant organisms
Cephalexin
500 mg qid
Cefuroxime
250–500 mg bid
Cefixime
400 mg daily
Use for resistant organisms
Ciprofloxacin
500 mg bid
Norfloxacin
400 mg bid
Levofloxacin
500–750 mg daily
Avoid fluoroquinolones as first line therapy to limit resistance emergence
Trimethoprim/ sulfamethoxazole
160/800 mg bid
s Avoid trauma
Doxycycline
100 mg bid
s Identify obstruction early
Recommended • Avoid indwelling catheter whenever possible s Use only for restricted indications s Discontinue catheter as soon as feasible s Use alternate voiding methods j Intermittent catheter j Condom catheter (men) • Catheter management s Aseptic insertion* s Closed drainage* s Drainage bag below level of bladder* j Secure catheter
bid twice daily, qid four times daily, tid three times daily
• Replace catheter prior to antimicrobial treatment for urinary infection Not recommended
Table 4 Parenteral antimicrobial regimens for treatment of urinary infection in catheterized subjects: Agent
Dose (normal renal function)
Gentamicin ± ampicillin
5 mg/kg q24h ± 1 g q6h
Tobramycin ± ampicillin
5 mg/kg q24h ± 1 g q6h
Amikacin ± ampicillin
15–20 mg/kg q24h ± 1 g q6h
Cefazolin
1–2 g q6h
Cefotaxime
1–2 g q12h
Ceftriaxone
1–2 g q24h
Ceftazidime Ciprofloxacin
1 g q8–12h 400 mg q12h
Levofloxacin
500–750 mg q24h
Ertapenem
1 g q24h
Imipenem/cilastatin
500 mg q6h
Meropenem
500 mg q6h
Doripenem
500 mg q8h
Piperacillin/tazobactam
3.375 g q8h
qXh every X hours
therapy of urinary infection with carbapenemase producing organisms is not yet determined. If the infecting strain remains susceptible to an aminoglycoside, this is an effective option for therapy (Table 5). Ampicillin or co-trimoxazole (trimethoprim/sulfamethoxazole; TMP/SMX) are appropriate oral therapy for susceptible bacteria. Cephalosporins, fluoroquinolones, and amoxicillin/clavulanic acid may be effective for more resistant organisms. Fluoroquinolones should be avoided as first line therapy if possible because of concerns with resistance emergence. Oral therapy for more resistant organisms is directed by the susceptibility results, as strains are often resistant to multiple first line oral agents.
• Routine catheter change • Antimicrobial coated catheters • Periurethral antiseptic cleaning • Antiseptic in drainage bag * Effectiveness unknown for long term catheters
5.4 Duration of Therapy Subjects are usually afebrile by 72 h following institution of appropriate antimicrobial therapy [14]. If the indwelling catheter remains in situ, as short a duration of therapy as possible is preferred to limit antimicrobial pressure promoting emergence of resistant organisms. A duration of only 7 days of therapy is recommended when there is a prompt clinical response following initiation of therapy. If the clinical response is delayed, the patient should be reassessed and the diagnosis of urinary tract infection reconsidered. Defervesence of fever will also be delayed in residents who have not had catheter replacement prior to starting antimicrobial therapy and, possibly, in those with severe renal impairment. Occasionally, residents with delayed response to therapy or early symptomatic recurrence post therapy have underlying abnormalities such as urolithiasis or abscess which may require further investigation and management.
6 Prevention Evidence based guidelines provide recommendations for prevention of catheter-acquired urinary infection, but are primarily relevant for short-term catheters [1, 16]. The
Catheter-Related Urinary Tract Infections in the Elderly
most important intervention to prevent infection is not to use an indwelling catheter. There are only a limited number of valid indications for catheter use. These include output monitoring, selected surgical procedures, acute or chronic retention, end of life care, and to assist in healing a sacral pressure ulcer in an incontinent patient [16]. Chronic indwelling catheters should not be used for the management of incontinence alone. The use of an indwelling catheter to assist healing of a sacral pressure ulcer should be individualized, as not all these patients require a catheter. If an indwelling catheter is used, it should be removed as soon as the indications for use are no longer present. A resident with a chronic indwelling catheter should have the need for the catheter reappraised periodically so it is removed promptly, when possible. Alternatives to an indwelling catheter should be used where possible. For men, external condom catheters may be appropriate. Condom catheters are associated with an increased risk of bacteriuria and, possibly, symptomatic urinary tract infection, compared to the use of no device, but these complications appear to occur less frequently than in residents with chronic indwelling catheters. Intermittent catheterization is appropriate for some residents. This strategy has a lower risk for invasive urinary tract infection and other complications compared with use of a chronic indwelling catheter based on studies in spinal cord injured populations [1]. There is insufficient evidence to determine whether a suprapubic catheter is beneficial compared with an indwelling urethral catheter [23]. The suprapubic catheter requires surgical insertion and skilled health care personnel for replacement, so is not generally recommended. Residents with chronic indwelling catheters are always bacteriuric, and it is not clear what, if any, interventions effectively prevent acquisition of bacteriuria. Acquisition of bacteriuria may be delayed by strategies such as use of aseptic technique at insertion, maintaining closed drainage, and prevention of reflux from the drainage bag to the bladder, but the utility of any of these in preventing symptomatic infection in residents with chronic catheters has not been evaluated. There is no evidence to prefer any particular type of catheter or catheter material [24]. When residents use leg bags for drainage, recommendations for maintaining closed drainage are not relevant. If leg bags are used they should be cleaned and replaced in a standardized manner to limit contamination [25]. The most important prevention goal for residents with a chronic indwelling catheter is to minimize development of symptomatic infection. Recommendations for catheter management to prevent catheter trauma should be followed, such as securing the catheter, and catheter obstruction must be recognized early and corrected promptly. The most common cause of catheter obstruction
9
is crystalline biofilm formation on the interior of the catheter associated with P. mirabilis bacteriuria [2]. There are no current interventions which specifically prevent this complication. The likelihood of development of catheter obstruction varies among individuals. Some residents have a high frequency of developing early or repeated obstruction. These individuals should be identified and monitored closely, with the catheter replaced promptly if there is any evidence of obstruction. Routine catheter replacement is not recommended [16]. Catheters should be replaced only if they are obstructed, bypassing, defective or otherwise not functioning, and prior to institution of antimicrobial therapy for the treatment of symptomatic urinary tract infection. Prophylactic antimicrobial therapy should not be given to prevent catheteracquired bacteriuria or symptomatic urinary infection. Antimicrobial therapy will not decrease the occurrence of bacteriuria or symptomatic infection, but is associated with isolation of organisms of increased resistance [23]. Other interventions such as acidification of the urine or use of methenamine mandelate and cranberry products are not effective [1, 26]. Antimicrobial coated catheters are not used for residents with chronic indwelling catheters as any effect of the antimicrobial catheter coating persists for only a few days following catheter insertion. Conflict of interest declare.
The author has no conflicts of interest to
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