UTI IN ELDERLY Zeinab Naderpour
Urinary tract infection (UTI) is the most frequent bacterial infection in elderly populations. While urinary infection in the elderly person is usually asymptomatic, symptomatic infection occurs frequently with associated serious morbidity and, rarely, mortality.
Recurrent urinary infection, either reinfection or relapse, is common for elderly persons. Reinfection is recurrent urinary infection with an organism isolated following antimicrobial therapy which differs from the pretherapy isolate. Relapse is recurrent urinary infection when the organism-isolated post-therapy is similar to the pretherapy isolate. When relapse occurs, the organism has usually remained sequestered at some site in the urinary tract and was not eradicated with antimicrobial therapy.
Persistent asymptomatic urinary infection is not associated with an increased risk of development of renal failure or hypertension. current evidence does not support an association between asymptomatic bacteriuria and decreased survival for
Causative Organisms of UTI Escherichia coli most common, 60~70%, but relatively low rate Proteus mirabilis Klebsiella pneumoniae enterococci more common than younger people Pseudomonas aeruginosa leukemia, aplastic anemia, after GI tract manipulation Staphylococcus rarely in elderly Melani PN. Clin Geriatr 2005
Factors Associated with UTI men BPH Prostate Ca Prostate stone Urethral stricture Etc. both Coexisting diseases Diabetes mellitus Cerebrovascular accidents Dementia Increased hospitalizations Instrumentation Urinary catheters Alterations of immunity women Genetic predisposition Loss of estrogen effect on genitourinary mucosa Changes in colonizing flora Cystoceles Increased residual volume Kunin CM. 1987
Risk factors In ambulatory postmenopausal women associations with asymptomatic bacteriuria urinary incontinence increased postvoid residual urine reduced mobility estrogen treatment. For postmenopausal women who are diabetic, an additional risk factor is the duration of diabetes.
Clinical presentation Clinical presentations of symptomatic infection may be similar to those in younger populations. Acute lower tract infection (cystitis) frequency, urgency, suprapubic discomfort, and dysuria. New or increased incontinence may also be a common presenting symptom in the elderly. Acute pyelonephritis classic triad of fever and costovertebral angle pain and tenderness, with or without associated lower urinary tract symptoms.
Clinical Deterioration Without Localizing Genitourinary Symptoms As the expected prevalence of positive urine cultures in the noncatheterized institutionalized population is as high as 50%, attributing fever to urinary infection because of an associated positive urine culture is usually not a correct diagnosis.
Clinical Deterioration Without Localizing Genitourinary Symptoms Only 10% to 15% of episodes of fever in bacteriuric institutionalized subjects without localizing genitourinary symptoms and without indwelling catheters are attributable to a urinary source. The positive predictive value of a positive urine culture for a urinary source of fever in the absence of genitourinary symptoms is less than 10%. Currently, however, clinical features that discriminate between a urinary and nonurinary origin, other than the presence of a chronic indwelling catheter, have not been identified.
Diagnosis History & physical examination laboratories A urine specimen for culture should be obtained prior to antimicrobial therapy for all institutionalized residents, for all men, and for women with a clinical presentation consistent with pyelonephritis. may diagnose acute uncomplicated cystitis based on history, P/E, and U/A alone, no need for culture to treat
Urine Specimen Collection Functionally impaired elderly subjects frequently cannot cooperate for optimal collection of a voided urine specimen. For incontinent women urine specimens may be contaminated with organisms which colonize the vagina and periurethral mucosa, compromising interpretation of the culture.
Urine Specimen Collection In-and-out catheterization should be used for urine specimen collection where a specimen is required from a woman who cannot provide a voided specimen. Catheterization should only be used where urine specimen collection is essential for clinical management as this procedure, itself, will precipitate bacteriuria in up to 5% of episodes.
The urine culture, of course, may also be negative if the specimen for culture is obtained after antimicrobial therapy has been initiated.
The presence of pyuria does not identify symptomatic infection or indicate a need for therapy. While a finding of pyuria is not a useful diagnostic test, the absence of pyuria is helpful in excluding UTI. A negative leukocyte esterase screen test, however, has high specificity and may be useful in excluding urinary infection.
MANAGEMENT There is no evidence that the asymptomatic bacteriuria causes symptomatic infection, and studies have consistently documented that treatment of asymptomatic bacteriuria is not effective in preventing symptomatic episodes. treatment of asymptomatic infection in ambulatory populations is not recommended. It follows that routine screening for bacteriuria in asymptomatic elderly ambulatory populations is also not appropriate.
Treatment of asymptomatic infection in ambulatory populations is not recommended. It follows that routine screening for bacteriuria in asymptomatic elderly ambulatory populations is also not appropriate.
No Screening for or Treatment of Asymptomatic Bacteriuria pre-menopausal, non-pregnant women diabetic women older persons living in community elderly institutionalized subjects persons with spinal cord injury catheterized patients while the catheter remains in situ Boscia JA, et al. JAMA 1987 Nicolle LE, et al. Am J Med 1987 Abrutyn E, et al. J Am Geriatr Soc 1988
Screening for or Treatment of Asymptomatic Bacteriuria pregnant women suspicious obstructive uropathy before TURP before urological interventions before prosthetic device hip or cardiac valve Nicolle LE, et al. Am J Med 1987 Abrutyn E, et al. Ann Intern Med 1994
The preferred oral therapy for susceptible gramnegative organisms would usually be nitrofurantoin or TMP/SMX. Amoxicillin is effective for treatment of infections with susceptible gram-positive organisms, such as group B streptococci or enterococci. It is not first-line therapy because of the high prevalence of antimicrobial resistance. Amoxicillin/ clavulanic acid and oral cephalosporins are also effective in the treatment of urinary infection, but are not recommended as first-line agents because of their broad-spectrum activity and cost.
Ototoxicity and nephrotoxicity with aminoglycoside therapy are unlikely when therapy duration is limited to 48 to 72 hours. Aminoglycosides should not be used, however, in persons with renal failure. Ampicillin or vancomycin are added for empiric therapy if enterococcal infection is a concern. For vancomycin-resistant Enterococcus, nitrofurantoin usually remains effective therapy and is the treatment of choice for cystitis.
PREVENTION Asymptomatic Infection Devices used for management of incontinence, including external urine collecting devices, intermittent catheterization and, of course, indwelling urethral catheters, contribute to bacteriuria. Avoidance or limitation of use of these devices will be effective in decreasing the frequency of bacteriuria. This may not, however, be an achievable goal in the individual elderly subject.
PREVENTION In people with bladder emptying using intermittent catheterization, the frequency of urinary infection is similar with a sterile or clean technique, so in the longtermcare setting a clean technique is appropriate, and less costly.
PREVENTION in Symptomatic Infection long-term low-dose prophylactic antimicrobial therapy Women who have recurrent symptomatic infections should be considered for referral to an urologist, as structural abnormalities in the lower urinary tract may predispose to recurrent infections. When these symptomatic episodes occur so frequently that they are distressing to the patient or interfere with daily routine, and no correctable pathology has been identified
Cranberry Juice Ingesting large quantities of natural urinary antiseptics, particularly cranberry juice, has been proposed. Cranberry juice may be effective through interference with bacterial adherence. While there seems no reason to discourage drinking cranberry juice, it is premature to endorse this as a means of preventing urinary infection or its complications in elderly populations.
CATHETER-ASSOCIATED UTI CAUTIis defined by bacteriuria and symptoms in a catheterized patient. The signs and symptoms either are localized to the urinary tract or can include otherwise unexplained systemic manifestations, such as fever. The accepted threshold for bacteriuria varies from 10 ³cfu/mL to 100000 cfu/ml.
CAUTI The formation of biofilm a living layer of uropathogens on the urinary catheter is central to the pathogenesis of CAUTI and affects both therapeutic and preventive strategies. Organisms in a biofilm are relatively resistant to killing by antibiotics, and eradication of a catheterassociated biofilm is difficult without removal of the device itself. Furthermore, because catheters provide a conduit for bacteria to enter the bladder, bacteriuria is inevitable with long-term catheter use
The typical signs and symptoms of UTI, including pain, urgency, dysuria, fever, peripheral leukocytosis, and pyuria, have less predictive value for the diagnosis of infection in catheterized patients. Furthermore, the presence of bacteria in the urine of a patient who is febrile and catheterized does not necessarily predict CAUTI, and other explanations for the fever should be considered.
catheter change during treatment for CAUTI. The goal is to remove biofilm-associated organisms that could serve as a nidus for reinfection
prevention systemic antibiotics, bladder-acidifying agents, antimicrobial bladder washes, topical disinfectants, and antimicrobial drainage-bag solutions have all been ineffective at preventing the onset of bacteriuria and have been associated with the emergence of resistant organisms.
The best strategy for prevention of CAUTI is to avoid insertion of unnecessary catheters and to remove catheters once they are no longer necessary. Evidence is insufficient to recommend suprapubic catheters and condom catheters as alternatives to indwelling urinary catheters as a means to prevent CAUTI.
catheterization may be preferable to long-term indwelling urethral catheterization in certain populations (e.g., spinal cord injured persons) to prevent both infectious and anatomic complications. Antimicrobial catheters impregnated with silver or nitrofurazone have not been shown to provide significant clinical benefit in terms of reducing rates of symptomatic UTI.