You're caring for Mabel Sullivan, a 78-year-old woman admitted to your subacute unit less than 48 hours ago. Mabel has been hospitalized for an exacerbation of her congestive heart failure. Her other diagnoses include atrial fibrillation, hypertension, diabetes, and mild memory impairment. Last night, Mabel seemed more confused and tried to get out of bed unassisted several times, prompting placement of a pressure-sensitive bed alarm. Early this morning, Mabel's alarm was sounding and she was discovered on the floor next to her bed with a large skin tear on her left arm. She'd been incontinent of urine, which appeared concentrated and had a strong odor. You decide to get a urine specimen after you assess and treat her injuries because you suspect she may have a urinary tract infection (UTI).
UTIs are the most common infection treated in acute and long-term-care settings and account for nearly a quarter of all healthcare-acquired infections (HAIs).1 UTIs are most common in women, with up to 50% of women reporting at least one UTI during their lifetime.1 Many women have recurrent UTIs; recurrence is most likely due to having a short urethra.1–3 The prevalence of UTIs in men increases with age due to physiologic changes such as prostate enlargement, incomplete emptying of the bladder, and decreasing testosterone levels.1 Asymptomatic bacteriuria, a lack of recognizable symptoms, and additional risk factors of decreased physical functioning, cognitive impairment, immobility, fecal incontinence, and incomplete bladder emptying in the elderly make the identification and treatment of UTIs in this population particularly challenging for nurses and other providers.1,4
Specifically, a UTI is an infection occurring in any of the urinary system structures, from the urethra up to the kidneys.5 Urine is a sterile, acidic medium that doesn't encourage bacterial growth; however, when bacteria from the surrounding skin invade the mucosal lining of the urinary structures, inflammation occurs, causing symptoms commonly associated with UTIs. In older adults, symptoms may be subtle or absent, but could include dysuria, frequent urge to void, urgency, loin pain, fever, foul smelling urine, and cloudy urine. The most common cause of UTIs is the bacteria Escherichia coli, which usually resides in the bowel. However Staphylococcus, Enterococcus, Proteus mirabilis, and Klebsiella are also routinely found as infecting organisms.5
UTIs are commonly categorized as symptomatic or asymptomatic; and complicated or uncomplicated. Asymptomatic bacteriuria occurs when there are no symptoms of urinary infection, but urinalysis shows bacteria are present. This is common in older adults and may lead to symptomatic infection. Despite the presence of bacteria and the risk of developing an infection, screening for or treating asymptomatic bacteriuria isn't recommended for community-based or institutionalized older adults, or patients with indwelling catheters. (See “Preventing catheter-related complications”.) The treatment of asymptomatic bacteriuria doesn't decrease the frequency or number of episodes of symptomatic infection or improve survival; there's no harm or adverse outcome associated with asymptomatic bacteriuria.6
Symptomatic bacteriuria occurs when bacteria invade the mucosal lining of the urinary structures, and the resulting inflammation causes symptoms such as urgency, frequent urination, and dysuria. In older adults, symptoms may be more subtle as in Mabel's case, presenting with increased confusion, agitation, incontinence, strong urine with a foul odor, and a fall.
UTIs may be complicated or uncomplicated. An uncomplicated UTI occurs in an otherwise healthy individual without urinary system abnormalities. Complicated UTIs occur when there's an indwelling catheter; neurogenic or other bladder dysfunction; renal insufficiency or disease; obstruction of the kidney, ureter, bladder, or prostate; or other illnesses such as diabetes. UTIs in the older adult are usually considered complicated due to advanced age and the comorbidities listed.
Other risk factors for UTIs in an older patient include decreased physical functioning and immobility, cognitive impairment or cerebrovascular disease, fecal incontinence, incomplete bladder emptying, and history of antibiotic therapy.1
Diagnosis of a UTI begins with a careful history of symptoms, a clean catch urine sample for culture and sensitivity if possible, or a dipstick test for leukocytes, nitrites, blood, and protein. Dipstick analysis is a quick, practical, and inexpensive way to screen which residents should have a culture and sensitivity analysis of their urine. The dipstick test is used in office settings and skilled nursing centers, and can be purchased in most any pharmacy. The presence of nitrites indicates that certain bacteria such as E. coli and Proteus are present because these microorganisms create nitrites. Leukocyte esterase is an enzyme present in white blood cells (WBCs); a negative result indicates that infection is unlikely.
Urine culture is regarded as the standard method for diagnosing UTI, but obtaining a midstream clean catch specimen that isn't contaminated is particularly difficult in some older adults. Bacteria are normally found in urine specimens because of the abundance of flora in the vaginal and external urethral areas, and because bacteria multiply rapidly in urine samples left standing at room temperature. Lab results presenting organisms in the urine culture should be interpreted based on the quantity present and clinical symptoms of the patient. A bacterial colony count greater than 100,000 cfu/mL of a single organism and pyuria (greater than 10,000 WBCs) are generally accepted as laboratory evidence of UTI. Any organism found in catheterized specimens should be evaluated carefully.
The Infectious Diseases Society of America Guidelines for the Diagnosis and Treatment of Asymptomatic Bacteriuria in Adults doesn't recommend routine screening or treatment of asymptomatic bacteriuria in older adults (residing in the community, or in long-term-care settings), or in patients with an indwelling catheter.6 Though these guidelines recognize that there is an increased risk of developing symptomatic UTIs in individuals with bacteriuria, treatment does not reduce the frequency of symptomatic infection or improve other outcomes.6
Antibiotics are required to treat most UTIs. The antibiotic selected should concentrate in the bladder, as opposed to the bloodstream or other tissues, and target specific bacterial susceptibility.7 While antibiotics reduce morbidity and mortality associated with UTIs, they're also associated with misuse and overuse. The result of antibiotic overuse has been the proliferation of drug-resistant strains of pathogenic organisms.7 Nitrofurantoin, trimethoprim, ciprofloxacin hydrochloride, and levofloxacin are antibiotics commonly used to treat UTIs in the older adult. Nitrofurantoin (Macrobid) is used for the treatment of uncomplicated UTIs and requires a 7-day course of treatment; it's also used for long-term suppression therapy and is well tolerated by many patients. Administer nitrofurantoin orally with food to enhance tolerability and absorption and minimize common side effects of headache, nausea, flatulence, and dark brown or yellow urine. Less common side effects to watch for include vomiting, diarrhea, dizziness, vertigo, temporary hair loss, asthma attacks in those with a history of asthma, and pulmonary hypersensitivity reactions. Patients with impaired renal function, anemia, diabetes, or other debilitating diseases are at increased risk for developing peripheral polyneuropathy, a severe and potentially fatal adverse reaction to nitrofurantoin.7
Trimethoprim/sulfamethoxazole (Bactrim DS, Septra) is usually given in one double strength or two regular strength pills twice a day for 14 days. The most common adverse reactions include nausea, vomiting, loss of appetite, rash, and itching. Use this medication cautiously in older adults and patients with renal impairment or AIDS because these patients are at increased risk for rare but severe hypersensitivity reactions.7
Ciprofloxacin hydrochloride (Cipro) is a fluoroquinolone broad spectrum antibiotic given as a regular strength 250-mg dosage twice daily or 500-mg extended release daily with food for 7 to 14 days in complicated UTIs.7 Common side effects include nausea, diarrhea, vomiting, and joint pain. Tendon ruptures can occur in older adults and individuals taking corticosteroids, and resulted in new black box warnings mandated by the FDA in July 2008.8 Dairy products such as milk, yogurt, or calcium-fortified juice may result in decreased absorption, and should be avoided when taking ciprofloxacin. Use caution if your patient is on warfarin, as the use of quinolones may increase bleeding times.7
Levofloxacin (Levaquin) is also a fluoroquinolone and works most effectively against Gram-negative bacteria. The usual dose in older adults is 250 mg twice daily for 10 days; side effects are similar to those of ciprofloxacin.
Cranberry products have been associated with a decrease in the incidence of symptomatic UTIs, particularly in women with recurrent UTIs, although the optimal dosage and form (juice, tablets, or capsules) isn't clear.9 The mechanism for reducing UTIs lies in a substance found in cranberries that changes surface properties of E. coli and prevents the bacteria from adhering to the bladder mucosa. Side effects can include gastroesophageal reflux, nausea, and frequent bowel movements.9 Patients on warfarin may need more frequent monitoring, as there's some evidence that cranberry juice can increase clotting times.1
Indwelling catheter-associated UTI (CAUTI) is the most common type of HAI, and is associated with additional complications such as trauma, blockage, and encrustation of the catheter.10 Risk factors for developing a CAUTI include the length of time the catheter remains indwelling, the method of insertion, quality of catheter care, and patient susceptibility. An indwelling catheter can mechanically irritate the urethral and bladder mucosa, which may reduce local defense mechanisms and promote the growth of bacterial biofilm, a collection of microorganisms that adhere to the surface of the catheter.10
Indications for the use of indwelling catheters are limited to critically ill or postoperative patients, urinary outlet obstruction or surgical repair of the genitourinary tract, acute urinary retention or sudden inability to void, severe urinary retention that can't be managed with intermittent catheterization, terminal illness, or a Stage III or Stage IV pressure ulcer that's not healing because of constant urine contamination.10
E. coli is responsible for nearly 80% of CAUTI; other pathogens include staphylococci, enterococci, Proteus, Klebsiella, Pseudomonas, and Enterobacter. The emergence of multidrug-resistant pathogens is a growing problem attributed to prolonged hospital stays and repeated treatment with broad spectrum antibiotics.10 The largest institutional reservoir of multidrug-resistant pathogens is attributed to CAUTI and may include Klebsiella, Enterobacter, Proteus, Citrobacter, Pseudomonas, enterococci and staphylococci, and Candida.11 Bacteria may enter the urinary tract in any of the following ways: (1) during catheter insertion, (2) bacterial ascent within the catheter from collected urine in the drainage tubing or catheter bag, (3) between the catheter and the urethra mucosa (extraluminal), and (4) cross-contamination when staff empties the drainage bag or manipulates the system.12
Older adults with indwelling catheters are among those at highest risk for developing urinary sepsis, a complication of UTIs associated with catheter use or invasive urologic interventions.12 Sepsis is a systemic inflammatory response to infection associated with organ dysfunction; in this case, the bladder. The inflammatory response includes symptoms of temperature elevation greater than 100.4° F, heart rate above 90 beats/minute, respiratory rate greater than 20 breaths/minute, and WBC count greater than 12,000. In urosepsis, the pathogenic organisms causing the UTI enter the bloodstream; the resulting bacteremia can result in severe sepsis characterized by hypoperfusion and hypotension, oliguria, and acute mental status changes.12
In Mabel's case
Mabel had a positive urine dipstick screen, so a clean catch urine specimen was obtained and sent to the lab for urinalysis, culture, and sensitivity testing. Results showed that she had over a 100,000 cfu/mL of Staphylococcus aureus in her urine and she was started on ciprofloxacin 250 mg by mouth twice daily for 10 days.
It's vital that nurses know how to identify the sometimes subtle indications of UTI in older patients. The risk factors, causes, and diagnoses are multifaceted, making management challenging. CAUTIs are the most common type of HAI and are more likely to develop into urosepsis than other types of UTIs. The type of infection, and sensitivities of the causative organism, determine the treatment regimen. Nursing knowledge of the prevention and management of UTIs will help to ensure that patients like Mabel receive prompt, effective treatment.
Preventing catheter-related complications
The following nursing care practices can help prevent catheter-related complications:
- Use small diameter catheter sizes of 14 or 16 French, as UTI rates are higher with larger diameter catheters.
- Use a 10-cc balloon instilled with 10 cc of sterile water, as larger balloons can result in the pooling of urine below the level of the catheter.
- Use generous amounts of lubricant during catheter insertion to minimize urethral trauma.
- Maintain a closed system, disinfect the catheter and drainage bag connection if system is opened, and disinfect the sampling port after aspirating a specimen.
- Practice good perineal hygiene, cleansing the female patient from front to back; antibacterial ointments and solutions haven't been shown to reduce CAUTI.
- Practice good hand hygiene and standard precautions.
- Keep the drainage bag below the level of the bladder at all times.
- Replace the catheter and drainage system if leakage or blockage occurs.
- Minimize urethral trauma by using an anchoring device to prevent tension or pulling on the catheter.
- Maintain good hydration.
- Avoid placing catheterized patients in the same room.
- Don't irrigate catheters.
- Don't obtain urine culture specimens from old catheters/drainage systems. If infection is suspected, obtain a specimen from a newly inserted catheter.
- Clean drainage bags with a 1:10 bleach solution or a vinegar solution.
- Remove catheters as soon as medically feasible.
Source: Newman DK. The indwelling urinary catheter: principles for best practice. J Wound Ostomy Continence Nurs. 2007;34(6):655–661.
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