Treating Acute Urinary Tract Infection in Postmenopausal Women

Acute urinary tract infection (UTI) accounts for approximately 3.6 million office visits annually by US women aged 18 to 75 years.¹ Bladder problems reportedly cost an estimated $16 billion a year in health-related expenses.¹ Although nonbacterial forms of UTI exist, bacterial infections are far more common. UTIs often manifest in an uncomplicated form, which can be successfully treated empirically. They are more common in women than in men as a result of differences in anatomy and hormones.¹

UTIs are the second most common types of bacterial infections seen by healthcare providers.¹ Eight million people are diagnosed with a UTI annually, and approximately 10% of postmenopausal women will report having had a UTI within the past year.² With advancing age, the UTI rate increases likely because of the hypoestrogenic state and vaginal epithelium atrophy and stress incontinence.

The purpose of this article is to demonstrate UTI as a clinical problem affecting postmenopausal women. The pathophysiology and applicable age changes will be discussed, along with relevant medical and nursing interventions. Lastly, an algorithm will be included to help guide clinicians in the evaluation and treatment of postmenopausal UTI.

Only acute UTIs in an ambulatory setting will be discussed, as recurrent UTIs, though frequent among this population, often require referral to a specialist.

Pathophysiology

UTI may occur in the postmenopausal woman due to the aforementioned physiologic changes of the body. In the following section, the various etiologies will be explained as they have been studied as predisposing risk factors in the elderly female population.

Vaginal atrophy and hypoestrogenic state

Vaginal atrophy is the thinning and inflammation of the vaginal walls due to a decline in estrogen.¹ Vaginal atrophy occurs most often after menopause, but it can also develop during breastfeeding or at any other time estrogen production declines in the body. This puts the elderly woman at risk for frequent UTIs since genital function is closely intertwined with healthy urinary system function. With vaginal atrophy, the risk of vaginal infections increases since atrophy leads to a change in the acidic environment of the vagina, making the elderly woman more susceptible to infection with bacteria, yeast, or other organisms.³

Stress incontinence

Incontinence refers to the involuntarily loss of urine from the body.⁴ Although not a normal consequence of aging, more than 40% of menopausal women have urinary incontinence.⁴ It occurs commonly in advanced age women due to the weakening of the muscles of the pelvic floor that occur under the rectum and bladder. The weakened pelvic floor contributes to mobility and displacement of the urethra during exertion.⁴ If pelvic muscles are not properly strengthened, incontinence prevails.

Additionally, decreasing amounts of estrogen after menopause also contribute to stress incontinence. Estrogen is responsible for keeping the urethra, vaginal, and pelvic floors healthy.¹ It also stimulates blood flow to the pelvic region, increasing strength in the pelvic muscles. Therefore, as estrogen decreases, muscles are simply weaker than they were before.⁴ This leads to a lack of strength to hold the opening to the bladder closed.⁵ UTI risk can also be increased with urinary incontinence due to prolonged use of soiled absorbent pads, which can provide an environment for bacterial growth.⁵

Additional causes

Diabetes is associated with a higher risk of acute symptomatic UTI in postmenopausal women.⁶ Diabetes results in several deviations of the host defense system that might result in a higher risk of certain infections.⁶ These abnormalities include immunologic impairments, such as impaired migration and phagocytosis from diabetic patients, and local complications related to neuropathy, such as impaired bladder emptying.⁵ Also, higher glucose concentration in urine may serve as a culture medium for pathogenic microorganisms.⁵

Clinical presentation

In general, UTI present clinically as dysuria, with symptoms of frequent and urgent urination secondary to irritation of the urethral and bladder mucosa.⁴ Older women with UTI may be asymptomatic, presenting with urosepsis or septic shock (severe hypotension, fever, tachycardia, tachypnea), have symptoms only of urinary incontinence, or have any combination of these symptoms.² In addition, symptoms of UTI that may occur in postmenopausal women but not in younger females may include mental changes or confusion, nausea or vomiting, abdominal pain, or cough and shortness of breath.⁷ An observational study of women aged 18 to 87 years within a primary healthcare setting revealed that a generalized sense of “feeling out of sorts” was frequent in adult women with acute uncomplicated lower UTI.¹

History of present illness

When a patient presents with symptoms of UTI, the clinician should elicit a full history of present illness (HPI). The HPI should include specifics regarding when the condition started, as the clinician should ask how many days/weeks the symptoms have been present. The typical features of UTI should next be examined: urinary urgency, frequency, dysuria, hesitancy, and low back pain.¹ Because postmenopausal women may not present to the clinician with “typical” UTI symptoms, it is important to investigate for atypical UTI presentations.⁴ Symptoms of increasing mental confusion, incontinence, unexplained falls, loss of appetite, and nocturia are atypical clinical manifestations that may occur in the older postmenopausal female.⁴

Physical examination

Initially, it is necessary to assess vital signs to help rule out sepsis. Before the physical assessment is performed, the patient is asked to void so that the urine can be examined and the bladder emptied prior to palpation.⁸ The abdominal examination should begin with inspection of the lower abdomen and palpation of the urinary bladder. Distention after voiding indicates incomplete emptying and can contribute to probability of contracting a UTI.⁷

Next, using standard precautions, the perineal examination should be performed in a supine or lithotomy position.⁸ The clinician inspects the area noting inflammation and any skin lesions around the urethral meatus and vaginal introitus.⁷ Often patients report “burning with urination” when normal, acidic urine touches labial tissues that are inflamed and ulcerated by vaginal infections.¹

Laboratory assessment

Laboratory evaluation for a UTI in this population is similar to the younger female, consisting of a urinalysis with a microscopic count of bacteria, white blood cells (WBCs), and red blood cells (RBCs). Bacteriuria is diagnosed using a clean-voided midstream sample. For a routine analysis, 10 mL of urine is required; smaller quantities are sufficient for culture.⁹ Traditionally, the presence of 100,000 pure colonies/mL indicates an infection.⁷

Urine dipstick testing for leukocyte esterase and nitrite is a fast and inexpensive diagnostic method.¹⁰ It is a good screening test, with a sensitivity of 75% and specificity of 82%.² However, urine culture confirms the type of microorganism and the number of colonies.¹¹ Urine culture is expensive and takes approximately 48 hours to obtain results.¹⁰ It is indicated when the UTI is complicated or not responsive to usual therapy or if the diagnosis is uncertain.¹⁰

This article originally appeared on Clinical Advisor