Diagnosing & Managing Urinary Tract Infections: Myths, Mysteries, & Realities

by Jacqueline Vance, RNC
Director of Clinical Affairs,
American Medical Directors Association

Urinary tract infections (UTIs) are the most common bacterial infections in the elderly.^1,2 Yet, many myths and misconceptions remain around how to recognize and treat these pervasive infections.

The question is, why the mystery? A systematic review of the literature showed that there have been virtually no new clinical advances in the prevention or management of UTIs since the 1960s. Is accurate information about UTIs missing or ignored? Do clinicians know how to interpret signs and symptoms and laboratory results for UTIs? What's the difference between bacteriuria (asymptomatic) and a symptomatic UTI?

This Special Report aims to lift the veil on these and other UTI "mysteries."

Risk Factors or Not?

Despite numerous studies, the risk factors for UTIs in the elderly remain unclear. Some articles cite such factors as alterations in urinary tract structure and limited functional status that would impair mobility, hygiene, and toileting.³ However, other articles question whether these are really risk factors or just ideas that are generally accepted.

Some suspected risks, such as neurogenic bladder, have been proven. Others, such as perineal hygiene, have not. While associations with UTIs have been recognized with age, menopause, instrumentation, and a history of recent urinary tract infection, factors that do not seem to increase the risk include diet and personal hygiene, including methods of cleansing after urination, defecation, and bathing practices.⁴ Yet, many practitioners believe the latter factors increase risk.

Another major risk factor for UTIs--hydration--is not always considered among risk factors in the literature. Yet, if you don't flush out the bladder, you wind up with stagnant urine, which increases the risk of a UTI.

But, whatever the risk factor, it is important to clarify just what characterizes a UTI versus the simple presence of bacteria in the urinary tract.

Bacteriuria or UTI?

According to the Association for Practitioners in Infection Control and the Society for Healthcare in Epidemiology of America, a laboratory confirmation of >100,000 colony-forming units (CFU)/mL is the usual standard to confirm a positive urine culture.

But a positive culture will not tell you whether a resident has a UTI or simply bacteriuria--a positive culture without dysuria, urinary frequency, incontinence of recent onset, flank pain, fever, or other signs of infection during the week before a urine sample was obtained.⁵ Asymptomatic bacteriuria is not a UTI, and should not be treated unless accompanied by symptoms that suggest a UTI. A diagnosis of UTI versus asymptomatic bacteriuria should be based on the combination of laboratory and clinical findings, not the laboratory findings alone.

Nevertheless, there is a tendency to manage LTC patients with positive urine cultures as though they have UTIs. For example, bacteriuria is often treated in the presence of new behavioral disturbances in dementia patients. Yet, bacteriuria does not cause mental status or behavioral changes.

And so it appears that, in spite of the evidence, we haven't learned to stop treating bacteriuria. "It's an unfortunate, common philosophy to treat bacteriuria with a 'what can it hurt' attitude," noted AMDA President-Elect James E. Lett, MD, CMD. "We have to stop taking the easy way out or jumping to conclusions, and start analyzing what's really going on with the patient."

Several points may help overcome the urge to treat bacteriuria, thereby avoiding overtreatment and potential antimicrobial resistance. It is important to recognize, for example, that bacteriuria alone does not cause chronic genitourinary tract symptoms such as incontinence. In addition, studies have shown that mortality for elderly persons with asymptomatic bacteriuria is similar to that of elderly persons without asymptomatic bacteriuria.

In fact, it is actually better not to treat asymptomatic bacteriuria. In untreated asymptomatic bacteriuria, the organisms (especially E. coli) tend to lose their virulence and become susceptible to the bactericidal effects of normal human plasma. Large amounts of bacteria in the urine may therefore protect against symptomatic bacteriuria caused by more powerful strains.³

Diagnostic Challenge

Since urinary tract colonization is prevalent in LTC patients, and since culture alone is inadequate for diagnosing an infection, how do we diagnose a UTI in the LTC setting?

Diagnosing a symptomatic infection can be challenging in the elderly in any setting, since the usual symptoms that may occur in a younger population--e.g., dysuria, urinary frequency, incontinence of recent onset, flank pain, and fever--may not be present. Therefore, diagnosis of UTI requires consideration not only of clinical symptoms, but also comorbidities and the severity of the presentation of an individual's illness.⁶

For example, confusion and delirium maybe indicate a severe UTI, as might a change in appetite and/or agitation. Or, an elder with urinary incontinence and a UTI may experience an increase in the number of episodes of incontinence.

Some physicians use the McGeer & MSHD definitions for LTC nosocomial infections to diagnose a symptomatic UTI. To meet the criteria for a suspected UTI without an indwelling catheter, three of the following must be met:

• Fever (>38 degrees C) or chills
• New or increased burning pain on urination (note that pain can be difficult to assess in patients with dementia)
• New flank or suprapubic pain or tenderness
• Changes in character of urine, and worsening mental function.

To meet the criteria for a suspected UTI with an indwelling catheter, two of the following must be met:

• Fever (>38 degrees C) or chills
• New flank or suprapubic pain or tenderness
• Changes in character of urine
• Worsening mental function

The Question of Culture

When or if to culture is another problem area in the management of UTIs in LTC. Many physicians feel "pressured" into obtaining a culture by nursing staff. A typical scenario is a phone call as follows: "Mr. Jones is acting funny and his urine smells foul. Can I have an order for a urine culture?" Then, if the physician does a culture and it's positive, the physician may feel pressured into treating, even in the absence of other clear signs of UTI.

"Stop the cascade before it starts," advised Dr. Lett. "It's unwise to culture if you already know the outcome and you know you aren't going to treat. Medical directors have to put a stop to the 'fear of surveyors' mentality--that is, the 'we have a positive culture so we have to do something about it or we'll get a deficiency' philosophy."

Many nurses interpret the physician's statement, "I'm not going to treat it" to mean "he won't treat something that should be treated." To circumvent such feelings, physicians should provide documentation in the patient's chart explaining why they don't need to treat. "If the nursing staff reports cloudy or foul-smelling urine in the absence of symptoms, increase fluids by 50% [if not contraindicated] for 24 hours. If the patient hasn't become symptomatic, don't do a culture," Dr. Lett said.

Also problematic is the practice of ordering "surveillance" cultures for patients with indwelling catheters (also see the next section on catheter-associated UTIs). This is not useful, since patients with indwelling catheters usually have some pyuria, almost always have bacteriuria, and usually are asymptomatic. In fact, asymptomatic bacteriuria can be identified in 95%-100% of patients who have indwelling catheters for over 30 days,^7-9 and therefore culturing in the absence of other symptoms is not recommended.

The Merck Manual of Geriatrics notes that the diversity of potential uropathogens mandates that urine cultures be obtained in all elderly persons with suspected UTI. The important point here is that an actual UTI should be suspected. In the debilitated elderly, a culture should only be obtained concurrent to the intention to treat. However, due to the frail condition of most LTC patients, treatment for a suspected symptomatic UTI with pain should not be delayed while waiting the usual three days to receive culture and sensitivity results.

If you feel your patient has a UTI, some may ask, why bother to culture at all? Just order a broad-spectrum antibiotic and get it over with!

The rationale for obtaining a laboratory culture is that the species involved can be identified and antibiotic susceptibility determined. If the patient is not improving on day three and a culture hasn't been obtained, you don't know if you need to change antibiotics or what the problem is.

Not treating in the absence of infection--or targeting the identified pathogens with an appropriate medication--also avoids the unnecessary use of more expensive, broader spectrum antibiotics. In the past, unnecessary treatment did not result in much cost in terms of resistance or expense. Now, however, when we overtreat, we may cause resistant bacteria, especially MRSA and VRE, while spending significant amounts of money.

What about performing dipstick tests instead of culturing? Dipstick tests can help identify bacteriuria, and can be performed in the facility.⁵ However, the use of dipsticks for high-risk patients is controversial. A study by the Department of Emergency Medicine in the Sharre Zedek Medical Center in Jerusalem, Israel, concluded that a dipstick analysis is not sensitive enough to diagnose UTI in high-risk patients in whom a missed diagnosis would have a serious consequence.¹⁰ Dipsticks also will not detect gram positive organisms such as enterococcus, which are increasingly a problem.

Catheter-Associated UTIs

Catheter-associated UTIs are common and carry increased risks of complications and morbidity. Therefore, every attempt must be made to minimize the duration of short-term catheterization and to avoid long-term catheterization altogether.¹¹

To assist with this, federal regulations mandate that certain criteria be met in order to justify the use of an indwelling catheter in a LTC facility. As noted in the State Operations Manual, an indwelling catheter should only be used "when there is valid medical justification. The resident should be assessed for and provided the care and treatment needed to reach his or her highest level of continence possible. The facility is expected to show evidence of any medical factors which caused the intervention."

However, complying with the regulation is not where the problem lies. The main problem for LTC practitioners seems to be in acute care, because hospitals--unlike LTC facilities--do not have to adhere to stringent criteria to justify the use of catheters. The result is that many LTC patients who are sent to hospitals come back catheterized, although they did not leave the facility that way. And although it may have been valid to catheterize a patient briefly, in many cases the catheter is inappropriately left in place throughout the hospitalization, thus increasing the patient's risk of UTI (see box at right).

The Bottom Line

The bottom line for LTC facilities is that having a standardized process in place for preventing and managing UTIs reduces morbidity and saves money.

"When you culture and treat when it's not indicated, think of the dollars that are wasted," said Dr. Lett. "If the cost of an average culture exceeds $100 and the average course of antibiotic treatment can exceed $90, then it makes sense for facilities to follow policies or guidelines about when to obtain cultures and when to appropriately treat. The potential savings to the health care system would be in the millions of dollars annually.

"Perhaps it would be a good idea for nursing facilities to create negative formularies [a list of drugs that cannot be used] or require the medical director to approve the use of a high-cost, broad spectrum antibiotic for the use of suspected UTIs in their facilities. Then," Dr. Lett concluded, "there would have to be a thought process behind prescribing."

The following Medical Directors shared their expertise for this Special Report: Harold Bob, MD, CMD; William Jaquis, MD, FACEP; James E. Lett, MD, CMD; Steven Levenson, MD, CMD; and Susan Levy, MD, CMD.

Follow this link to Part 2 of the article, "Dispelling UTI Myths: True of False?"

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