Urinary Incontinence: Is There Effective Therapy?

ABSTRACT: A thorough history is generally sufficient to determine whether a patient has urge, stress, mixed, overflow, or functional incontinence. Most causes of urge incontinence are idiopathic; however, other conditions that can produce urgency and frequency must be ruled out. Therapeutic measures include elimination of bladder irritants, urge suppression, and timed voiding. Antimuscarinic medications are the mainstay of therapy. The newer agents have fewer peripheral anticholinergic effects than the older ones. Pelvic floor exercises are an important technique for stress incontinence. They improve periurethral muscle tone, which can enhance urethral resistance. Overflow incontinence results from a high-grade urinary outflow obstruction or poor bladder contractility. The obstruction should be treated if possible.

Urinary incontinence is common—especially among older adults—but underdiagnosed. Many persons with this disorder are reluctant to discuss it with their physicians; often, only direct questioning can uncover the problem. It is estimated that only 45% of women who reported symptoms of urinary incontinence occurring at least weekly ever sought care for their symptoms.¹ Because of this, providers should initiate the discussion of urinary symptoms with each patient and then determine the extent to which they impact the lifestyle of the patient.

Incontinence should never be considered a normal change of aging and is frequently accompanied by medical and social complications (Box I). The associated costs exceed $16 billion annually.²

The causes of incontinence are numerous. Because treatment options vary widely depending on the cause, an accurate diagnosis is essential. Fortunately, the evaluation is relatively straightforward.

In this article, I review the components of the evaluation and describe nonpharmacologic and pharmacologic management strategies for the principal types of incontinence.

TYPES OF INCONTINENCE

Persistent incontinence includes urge, stress, mixed, overflow, and functional incontinence. Stress incontinence is seen primarily in women, but overactive bladder and urge incontinence can affect both sexes.³

Patients generally have 1, or occasionally 2, types of incontinence; in most cases, the specific type(s) can be determined by the history. Ask the patient about:

•Frequency of leakage.

•Presence of nocturia.

•Volume of urine lost.

•Duration of symptoms.

•Conditions that precipitate urine loss.

•Whether a sensation of urgency precedes urine loss.

Evaluate comorbid conditions, especially those related to the genitourinary or neurologic systems. Occasionally, physical findings and laboratory results help determine the type of incontinence. A voiding diary (Box II) is a very useful tool in the evaluation of a patient with incontinence. Note that treatment is more likely to be effective if the incontinence is of recent onset.

URGE INCONTINENCE

This condition is usually a manifestation of overactive bladder, a syndrome characterized by urinary urgency, frequency, and nocturia caused by uninhibited bladder contractions.⁴ Many women with overactive bladder also have urge incontinence. In most patients, no specific cause of the symptoms is apparent and no abnormalities (metabolic or pathologic) that could produce the symptoms are present.⁵

The prevalence of overactive bladder increases with age and affects men and women equally. However, urge incontinence is more common in women as a result of anatomic differences. Patients with overactive bladder have premature, involuntary bladder contractions that produce symptoms of urinary urgency. Urinary frequency (8 or more micturitions in 24 hours) and nocturia (2 or more episodes per night) are also common. Typically, patients describe the loss of moderate volumes of urine.

Patients often recognize triggers that result in contractions of the detrusor muscle and symptoms of overactive bladder. Common triggers include hearing or feeling running water, inserting a key in the lock of one’s door, and exposure to cold temperatures. A patient’s knowledge of these triggers can be important in the management of symptoms.

History. The evaluation begins with a detailed history. A voiding diary (see Box II) can be highly useful. It typically documents urinary frequency, volume of voided urine, precipitating events, fluid intake volume, type of fluid ingested, and the presence or absence of urinary urgency.

Other conditions that produce urinary urgency and frequency must be ruled out (Table 1). Urinary frequency and urgency are also associated with a generous fluid intake and, on rare occasions, hyperglycemia and hypercalcemia.

Physical examination. The physical examination is usually not very helpful in establishing a diagnosis of overactive bladder. However, the vaginal mucosa should be assessed for atrophy and inflammation, which may result from estrogen deficiency. A bimanual pelvic examination should evaluate for bladder tenderness. Typically, the bladder is not palpable, since urinary retention is not common in patients with overactive bladder. If urinary retention is suspected, a postvoid residual urine measurement is recommended. A prostate examination is warranted because benign prostatic hyperplasia (BPH) and, occasionally, prostate cancer may produce symptoms of overactive bladder. In frail elderly persons, fecal impaction must be ruled out.

Laboratory testing. Order a urinalysis to check for pyuria, which may indicate a bladder infection or bladder inflammation. The presence of hematuria, either microscopic or gross, is not associated with any type of urinary incontinence. The presence of hematuria requires further investigation. A urine culture is also necessary in those who have evidence of a urinary tract infection. Urodynamic testing is usually unnecessary, and the findings often do not correlate with the patient’s symptoms. A urine cytology or cystoscopy is usually not performed unless hematuria is present.

Management. The management of overactive bladder/urge incontinence includes nonpharmacologic and pharmacologic treatment.⁶ Nonpharmacologic measures should be attempted as initial therapy.

Nonpharmacologic measures. Ensure that patients have adequate fluid intake; highly concentrated urine may promote urinary urgency. Discourage excessive fluid intake because this may result in urinary frequency. Review common dietary bladder irritants with the patient. These substances should be eliminated one at a time to determine whether they are contributing to the problem. Caffeine is the most common bladder irritant; others include carbonated beverages, alcohol, and tea or coffee. Be sure that patients are aware of which triggers cause bladder contraction.

Encourage patients with overactive bladder to practice urge suppression. This involves a contraction of the pelvic floor muscles in response to detrusor contraction and a strong urge to void. The contraction is held until the urge passes, usually 10 to 15 seconds. Strengthening of pelvic floor muscles and Kegel exercises are also helpful for patients with overactive bladder.⁷

Timed voiding may also be recommended. The patient’s typical voiding frequency is determined through use of the voiding diary, and the patient is instructed to void slightly sooner than her normal frequency. The time between voidings is increased every few days for several weeks. Patients with impaired mobility may have fewer episodes of incontinence if they have easy access to a commode, bedpan, or urinal.⁸

Pharmacologic therapy. Antimuscarinic agents, such as oxybutynin and tolterodine, have been the mainstay of pharmacologic therapy. They are available in immediate- and extended-release forms. Oxybutynin is also available as a transdermal patch.

The main adverse reactions associated with the antimuscarinic agents are peripheral anticholinergic effects, including dry mouth, constipation, blurred vision and, in elderly patients, the potential for confusion. The extended-release and transdermal forms are associated with a lower incidence of peripheral anticholinergic effects.^9,10

Trospium chloride, solifenacin, and darifenacin are newer medications approved for the treatment of overactive bladder.^11-13 Their mechanism of action and efficacy are comparable to those of the earlier agents; however, they act primarily on the urinary bladder and have less effect on peripheral cholinergic receptors. This should result in fewer peripheral anticholinergic effects. In general, anticholinergic agents should be used with caution in men with obstructive symptoms because of the risk of urinary retention. These agents are contraindicated in patients with angle-closure glaucoma.

Tricyclic antidepressants can be effective for mixed incontinence (combination of urge and stress incontinence), although they are not FDA-approved for this indication. They have significant anticholinergic activity resulting in detrusor relaxation and a-adrenergic activity that promotes contraction of the internal urinary sphincter. Postmenopausal women with overactive bladder may respond to vaginal estrogen if their symptoms are attributable to atrophic urethritis, although the effectiveness of this treatment has not been well documented. Systemic estrogen should not be used in women with urinary incontinence. It has been shown to possibly increase the risk of all types of urinary incontinence.^14-16

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STRESS INCONTINENCE

Stress incontinence involves the involuntary loss of urine during activities that cause a transient increase in intra-abdominal pressure, such as coughing, sneezing, laughing, and running. This common cause of urinary incontinence more frequently affects women. Stress incontinence in men usually results from damage to the internal urinary sphincter, such as may occur after prostatectomy for prostate cancer. In addition to female sex, other risk factors for stress incontinence include childbirth (especially vaginal deliveries), aging, and obesity.¹⁷

Stress incontinence results from hypermobility of the urethra/bladder neck or intrinsic sphincter deficiency. Pelvic muscle laxity may contribute to the descent of the bladder neck and proximal urethra from the normal intra-abdominal position to a position within the pelvis when intra-abdominal pressure is increased. This leads to inadequate closure of the urinary sphincter. The pressure within the bladder exceeds the resistance within the urethra, and urine flows out of the bladder. Patients with intrinsic sphincter deficiency have defective closure of the internal sphincter, which results in an inability to contain the urine within the bladder when bladder pressure is increased. Urethral hypermobility and intrinsic sphincter deficiency may coexist. In both situations, urethral resistance is inadequate and urine is lost with activities resulting in increased intra-abdominal pressure.

History. Most patients describe a loss of small amounts of urine in response to physical activities that temporarily increase intra-abdominal pressure such as laughing, coughing, or sneezing. Stress incontinence is more likely to occur when the bladder is full. Most patients recognize this and urinate frequently to prevent their bladder from filling.

A wide variation in symptom severity exists. Some patients lose urine only during vigorous physical activities, such as running or playing tennis, while others lose urine when walking or even when assuming a standing position. Multiple vaginal deliveries and the use of forceps may increase the risk of stress incontinence. Premature loss of estrogen, caused by either menopause or surgery, also increases the risk. A voiding diary is useful in the evaluation of patients with stress incontinence.¹⁸

Physical examination. A pelvic examination helps establish the degree of uterine, bladder, or rectal prolapse. Evaluate the patient’s ability to contract her pelvic floor, because this will be useful in pelvic floor muscle exercises. Check for intra-abdominal and pelvic masses and tenderness. The anal sphincter tone should also be assessed. Although a detailed neurologic examination is usually not necessary, it should be determined whether CNS, spinal cord, or peripheral nerve disease is present.

Provocative testing can be useful. This is performed by having the patient with a full bladder cough forcefully in the standing position, as the examiner places a pad over the perineum. Loss of urine is consistent with stress incontinence.

It is also wise to teach the patient how to correctly perform pelvic floor exercises during the pelvic examination. During the vaginal examination, the examiner should place one finger on each side of the urethra and have the patient contract her pelvic floor muscles. The examiner should be able to detect the contraction of these muscles, and appropriate feedback is then given to the patient.

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Management. Strategies are listed in Table 2. Nonpharmacologic techniques are the mainstay of therapy and include pelvic floor exercises, weight reduction, and smoking cessation. Management of chronic cough is recommended when appropriate.

Nonpharmacologic measures. Perhaps the most effective treatment of stress incontinence is weight loss. An 8% reduction in weight was shown to result in a 47% decrease in stress incontinence in 338 overweight and obese women.¹⁹

Pelvic floor exercises (Kegel exercises), which consist of high-intensity contraction of the pelvic floor muscles, produce improved periurethral muscle tone, which can enhance urethral resistance.¹⁵ Clinical improvement rates of up to 95% have been reported with pelvic floor exercises.⁵ The muscles are contracted for 10 seconds. Ten sets of contractions are done 4 times a day. It may take up to 2 months for improvement in symptoms to be noticed. Many women have difficulty in performing pelvic floor exercises correctly because they cannot isolate the correct muscles. The technique may be taught during a pelvic examination or with biofeedback.²⁰

Vaginal cones are sometimes used during pelvic floor exercises. These devices are inserted into the vagina and kept in place by contraction of the pelvic floor muscles. The cones come in a variety of weights; the patient is instructed to insert progressively heavier cones as the pelvic floor muscles strengthen.²¹

Intravaginal pessaries can be used to support the bladder neck and increase urethral resistance; they are most useful in those who have mild symptoms and no history of pelvic surgery. Younger women who have symptoms only with vigorous activity may find that inserting a tampon before the activity provides the needed increased urethral resistance. Intraurethral plugs are also available for this purpose. Patients must have adequate manual dexterity to insert these plugs, which sometimes cause urethral irritation.

Pharmacologic therapy. Medication is occasionally used for stress incontinence, although no pharmacologic treatment has been approved by the FDA for this condition.²² Sympathomimetic compounds, such as pseudoephedrine or tricyclic antidepressants, have a-adrenergic agonist activity and may increase internal urinary sphincter tone. However, pseudoephedrine can elevate the blood pressure and cause tachycardia; moreover, tolerance to this drug’s effects on the internal sphincter develops quickly.

Tricyclic antidepressants, in addition to troublesome anticholinergic effects, may also have potentially serious cardiovascular effects. There is no role for systemic estrogen therapy in the management of stress incontinence. Topical estrogen, applied in cream, tablet, or elastomer ring forms, may increase mucosal thickness in the urethra as well as urethral resistance. Although this is theoretically beneficial, definitive data on the effectiveness of topical treatment are lacking.¹⁵

Duloxetine, a selective serotonin-norepinephrine reuptake antagonist indicated for the treatment of depression and neuropathic pain, is occasionally used to improve symptoms of stress incontinence. Duloxetine stimulates the pudendal nerve in the sacral spinal cord, which results in contraction of the external urinary sphincter.²³ The primary adverse effect of duloxetine is transient nausea.

Surgical treatment. Surgery may be helpful for certain patients, but it should be considered only after other techniques have failed. Procedures include bladder suspension, urethral sling, placement of an artificial urethral sphincter, and injection of sphincter bulking agents. The procedure selected depends on the cause of the symptoms.

A patient with intrinsic sphincter deficiency may benefit from a urethral sling. This minimally invasive procedure can be performed on an outpatient basis with local or regional anesthesia. Either biologic or synthetic graft material can be used.²⁴

Injectable periurethral bulking agents are also occasionally used in patients with intrinsic sphincter deficiency. It is hypothesized that they increase urethral resistance to urine outflow.

MIXED INCONTINENCE

Mixed urinary incontinence is a combination of stress and overactive bladder/urge incontinence. Those with mixed incontinence often describe a confusing history. Patients usually report that an event such as a cough, sneeze, or other physical activity induces urine loss. This results in a forceful contraction of the detrusor muscle and loss of the remaining bladder volume. This form of incontinence affects up to 30% of women who are older than 60 years. Treatment usually requires management of both conditions.

OVERFLOW INCONTINENCE

Overflow incontinence, an uncommon type of incontinence, is attributable to either a high-grade urinary outflow obstruction or poor bladder contractility (hypotonic or atonic bladder). Patients experience frequent or constant dribbling of urine. As urine is produced, it continues to fill the already distended bladder. Urine flows only when the pressure within the bladder exceeds urethral resistance. In men, overflow incontinence is most commonly associated with BPH. It may also be occasionally seen in frail elderly persons who have fecal impaction.

A hypotonic bladder is sometimes seen in diabetic patients with autonomic neuropathy. It may also affect elderly patients after hospitalization for a surgical procedure. In most cases, these patients experience eventual restoration of bladder contractility. Medications commonly given postoperatively—including narcotics and calcium channel antagonists—may contribute to a hypotonic bladder and overflow incontinence.

Treatment depends on the cause. Treat obstruction if possible. For men with BPH, a variety of transurethral procedures are available to relieve urinary outflow obstruction.^25-27 The management of an atonic/hypotonic bladder includes initial placement of an indwelling urinary catheter, then intermittent catheterization. The frequency of catheterization is based on the urine volume obtained at each catheterization. Although the use of a cholinergic agonist, such as bethanechol, has theoretical benefit, many patients cannot tolerate its adverse effects; thus, it is rarely prescribed.²⁸

a-Adrenergic antagonists, such as doxazosin, terazosin, tamsulosin, and alfuzosin, can improve urinary flow in men with BPH but usually are of little benefit in the management of obstructive uropathy with resulting overflow incontinence. They may be useful in patients with less severe urinary obstruction.

FUNCTIONAL INCONTINENCE

This condition is attributable to an iatrogenic, physical, or cognitive disorder, such as advanced arthritis, impairment from a stroke, or dementia. Patients typically have normal urinary function. Functional incontinence is much more common in elderly patients than in younger ones. It may also been seen in patients with mobility limitations or in those who are bedridden, especially when side rails or restraints are used.

Certain medications may also produce functional incontinence. These include potent diuretics (rapid production of urine); a-adrenergic antagonists (decreased urinary sphincter tone); a-adrenergic agonists (increased urinary sphincter tone); anticholinergics; and narcotics or calcium channel antagonists (impaired detrusor contraction).

Successful treatment of functional incontinence requires management of the contributing factors. Periodically review the medications of patients who have this condition. Scheduled toileting and awareness of behavioral signs that indicate a desire to void are also helpful. The placement of a urinal, bedpan, or commode close to the bed may relieve the problem.

WHEN TO REFER

Further evaluation by a urologist or a urogynecologist is recommended in the following settings:

•The diagnosis is uncertain.

•The patient does not respond to treatment.

•There is evidence of incomplete bladder emptying or hematuria.

•It is determined that surgery may be necessary.