Differentiating and Managing Urinary Incontinence in Women

Darryl S. Chutka, MD

Urinary incontinence (UI) is extremely common, with millions of people in the United States experiencing it. While it occurs in both sexes, UI is more than twice as common in women.1 UI also becomes more common with advancing age, with a prevalence of approximately 25% in young women2 and up to 75% in women over the age of 75.3

The problem can range from a minor nuisance to a major source of embarrassment, and it can result in a major change in a person’s lifestyle. Most cases of UI can be treated effectively, yet it is estimated that less than half of women with UI mention it to their health care provider.4 Because of this, providers need to ask their patients about the presence of symptoms of UI, then determine the degree to which they affect the patients’ lifestyle. An accurate diagnosis is important, since there are several causes of UI, and effective treatment depends on the specific type of incontinence.

The 4 predominant types of UI are urge, stress, overflow, and functional. In women younger than 60 years, stress incontinence is most common, representing just more than half of women with UI. In women over 60, stress and urge incontinence are equally common. In addition, a combination of stress and urge incontinence can occur and is referred to as mixed incontinence.

Stress incontinence

Stress incontinence results from the involuntary loss of urine due to inadequate urethral resistance from the internal urinary sphincter. It can occur during a variety of activities that result in an increase in intra-abdominal pressure, such as sneezing, laughing, coughing, jumping, or running. Risk factors other than being female include a history of vaginal childbirth, overweight or obesity, and older age.5

The 2 mechanisms for stress incontinence are hypermobility of the urethra and bladder neck, and intrinsic urinary sphincter deficiency. Laxity of the pelvic muscles can result in a descent of the bladder neck from the intra-abdominal location to the pelvis. This can result in inadequate closure of the internal sphincter, resulting in urine loss with activities that increase the intra-abdominal pressure. Women with intrinsic sphincter deficiency have a defective internal sphincter closure, which also results in intermittent urine loss.

History. Patients with stress UI describe a loss of small amounts of urine with activities that result in an increase in intra-abdominal pressure. The severity of symptoms is quite variable. Some women will lose urine only with extremely vigorous activity such as running, while women with severe stress incontinence can lose urine simply going from a sitting position to a standing position. Symptoms tend to be more common with a full bladder. Because of this, women with stress incontinence may limit their fluid intake and urinate more frequently to keep their bladder empty.

Physical examination. A pelvic examination should be performed in women presenting with symptoms of stress UI. The examiner should check for evidence of bladder, uterine, or rectal prolapse, as well as any pelvic or abdominal masses. A patient’s ability to contract her pelvic floor muscles also should be evaluated at this time. The patient’s ability to perform this activity correctly will play a role in the management strategies for stress incontinence. One can easily check for stress incontinence by having the patient with a full bladder stand and produce a forceful cough. The examiner should place a pad over the perineum and observe for urine loss, a finding that would be consistent with a diagnosis of stress UI.

Diagnostic tests. No laboratory tests help in the diagnosis of stress UI, although urinalysis should be done as a minimum in any patient with symptoms of UI.

Management. No pharmacologic treatments have been approved by the US Food and Drug Administration for the treatment of stress UI. Management is with nonpharmacologic therapies. When appropriate, weight loss can be very effective in reducing incontinence symptoms. In women who are overweight or obese, as little as an 8% weight loss was associated with a 47% reduction in stress UI.6

For women who have stress incontinence due to a persistent cough, it is useful to look for reversible causes of the cough, such as the use of an angiotensin-converting enzyme inhibitor or the presence of poorly controlled asthma. If the cough can be treated, the incontinence may resolve.

Pelvic floor or Kegel exercises can be very useful and consist of repeated high-intensity pelvic floor contractions. When done regularly, pelvic floor exercises can result in improvement in periurethral muscle tone and improved urethral resistance. Pelvic floor exercises have shown potential for significant clinical improvement and are one of the most effective forms of treatment,7,8 with improvement rates of 50% to 70%.9 The key to success with the exercises is the repetition over time. The patient needs to be able to identify the pelvic floor muscles. This can be taught during the pelvic examination. As the patient contracts her pelvic floor muscles, the examiner should feel the muscles contract just lateral to each side of the urethra. Occasionally, some women will have difficulty contracting these muscles and may need assistance from a physical therapist. Biofeedback can also be very helpful.10 The muscles must be contracted for at least 10 seconds, with 10 sets of contractions performed 4 times a day. Symptoms may not improve for at least 2 months. Once benefit is achieved, the patient must continue the exercises or the effects quickly will be lost.

Several mechanical device treatment options are available. Intravaginal incontinence pessaries can be inserted by the patient into the vagina and provide support to the bladder neck, increasing urethral resistance and preventing urine loss. A similar benefit can be achieved in younger patients with the use of a vaginal tampon. Bladder supports are nonabsorbent, removable devices that are inserted like a tampon and provide support to the urethra, preventing undesired urinary loss. Intraurethral plugs also are available and can be inserted prior to vigorous exercise. All of these devices require a patient to have good manual dexterity and adequate vision. They also have the potential to cause urethral irritation. Absorbent products including pads, shields, undergarments, and adult diapers are readily available and commonly used by women with UI.

Surgical treatment options are considered for patients with more advanced symptoms or in whom conservative treatment is ineffective. Bladder neck suspensions can be performed to increase the bladder outlet resistance but usually are done only in combination with a hysterectomy. A variety of urethral slings can be placed as an outpatient procedure and also result in an increase in outflow resistance, preventing the loss of urine from the bladder.

Urge Incontinence

Urge incontinence commonly is a result of an overactive bladder (OAB)—a bladder that produces involuntary contractions well before it is full. Symptoms can include increased urinary frequency and urgency. These symptoms can result in a strong sense of urinary urgency and the need to empty the bladder. Patients may discover a variety of triggers that result in urinary urgency, such as placing a key in the lock of their door or seeing running water. It is often helpful when patients recognize these triggers, because they can be used as part of the management of OAB.

History. It is important to ask patients about urinary frequency, nocturia, and urgency. Most women with urge UI will lose moderate volumes of urine during episodes, typically more than women with stress UI. Any precipitating events or triggers should be explored. Both the amounts and types of fluids ingested should be determined. A significant caffeine intake is a common contributor to urinary urgency. Other bladder irritants may include carbonated beverages and alcohol. Although OAB is the most common cause of urge incontinence, several other conditions must be ruled out, including lower urinary tract infection, atrophic urethritis, bladder tumors, bladder stones, and rarely hyperglycemia or hypercalcemia. A voiding diary can be useful in helping to establish voiding patterns, symptoms, and fluid intake of patients with urge incontinence.

Physical examination. Very few findings of a physical examination help establish a diagnosis of urge incontinence. Most of the information will come from the medical history. A pelvic examination should be performed to assess the status of the vaginal mucosa, checking for the possibility of vaginal mucosal atrophy secondary to estrogen deficiency. This finding implies that the patient also may have atrophic urethritis. A bimanual examination should be done to check for any bladder tenderness or pelvic masses.

Diagnostic tests. Urinalysis results should be checked for pyuria, which may indicate bladder or urethral inflammation. Any degree of hematuria needs to be investigated, because none of the causes of incontinence are associated with hematuria, either gross or microscopic. Either a urine culture or a urine Gram stain is recommended to rule out a urinary tract infection. Urodynamic studies may be helpful in rare circumstances in which the medical history is confusing, such as a patient with mixed incontinence, but they are not needed in the vast majority of cases. Urodynamic studies often yield confusing results that may not correlate with the symptoms the patient describes.

Management. The management of patients with OAB and urge incontinence starts with nonpharmacologic strategies.11 Patients should have fluid intake that is adequate but not excessive to the point at which urinary frequency results. Urine that is concentrated may promote more urinary urgency. Bladder irritants, most importantly caffeine, should be avoided. It is important to search for sources of caffeine other than coffee. Many carbonated beverages contain relatively large quantities of caffeine. For some patients, carbonated beverages can act as a bladder irritant. Alcohol can produce urinary frequency through its diuretic effect.

Patients should be educated about triggers that result in symptoms of urgency. These commonly include driving the car into the driveway, inserting a key into the lock of one’s house, or seeing running water. Once these triggers are known, the patient can use a technique known as urge suppression. Once the sensation of urinary urgency develops, the patient should stop her activity and contract her pelvic floor muscles for 10 to 15 seconds. In many cases, the sensation of urgency temporarily resolves with this exercise. For women with mobility problems, the use of a bedside commode, bedpan, or urinal may be helpful.

Timed voiding may be another option for some patients with OAB or urge UI. A voiding diary is useful to help determine typical voiding frequency. Once this is known, the patient is instructed to void regularly slightly sooner than her normal frequency. Every few days, the time between voidings is increased gradually.

Pharmacologic therapy often is most useful when combined with one or more of the previously described nonpharmacologic treatments. The majority of the products available for treating OAB are effective due to their antimuscarinic activity. These agents suppress premature detrusor contractions but typically produce adverse effects including dry mouth, constipation, and blurred vision, especially in elderly patients. Oxybutynin and tolterodine have been available for many years. Newer products include solifenacin, darifenacin, and trospium. They are equally effective but may be better tolerated, with fewer peripheral antimuscarinic adverse effects.12 This medication class must be used with caution in patients with any preexisting condition that results in impaired bladder emptying, such as a hypotonic bladder. Use of these medications in this scenario can lead to increased urinary retention.

Mirabegron is a relatively new pharmacologic option for urge incontinence therapy. It is a β3 agonist with the advantage of having no antimuscarinic activity; however, it may promote an elevated blood pressure. 

Additional albeit infrequently used options for treatment include onabotulinum toxin A injections into the detrusor wall and capsaicin bladder infusions. Sacral neuromodulation therapy has been shown to be effective in more refractory cases of OAB. During sacral neuromodulation, a surgically implanted pulse generator sends mild electrical signals through the sacral nerves to the bladder. It has demonstrated cure rates of up to 50% and improvement rates of up to 90%.13,14

Overflow Incontinence

Overflow incontinence is a very uncommon cause of incontinence and reflects either a bladder that contracts poorly or a high-grade bladder outflow obstruction. Patients with this condition have symptoms of very low urine flow and, frequently, urinary dribbling throughout the day and night. The bladder empties when the pressure within the bladder is greater than the urethral resistance. A postvoid residual urine volume assessment will identify women with this condition.

Patients with overflow incontinence have the potential to eventually develop a significantly enlarged bladder and, rarely, hydronephrosis that can result in renal dysfunction. Causes of hypotonic bladder include peripheral neuropathy, and it also may be seen temporarily in elderly patients who are hospitalized for a surgical procedure. Most of these patients have a temporary hypotonic bladder, and bladder function eventually returns. The use of narcotics also can contribute to a poorly contractile bladder.

Overflow incontinence due to a high-grade bladder obstruction is relatively uncommon in women. It is more common in men due to untreated benign prostatic hyperplasia, but it may occur in women due to a fibroid uterus. A hypotonic bladder usually requires some type of bladder drainage including urinary catheters. Many postoperative patients will regain bladder function, and temporary intermittent catheterization should be used initially. For persons whose bladder function is not expected to return, an indwelling catheter usually is required.

Functional Incontinence

Functional incontinence may be caused by a variety of conditions. Patients with physical impairments, such as those confined to a bed or chair, can have difficulty with mobility and may not have adequate access to a restroom. Some with significant cognitive disorders may not recognize the symptoms of a full bladder. Some medications may result in an impaired urinary system, affecting either urine storage or elimination. These include potent diuretics such as furosemide, which can result in rapid bladder filling, or ɑ1 adrenergic agonists such as decongestants, which can produce a tightening of the bladder neck muscles, increasing outflow resistance. Narcotics, calcium-channel antagonists, and anticholinergic medications can impair bladder contraction and promote urinary retention. Prazosin, terazosin, doxazosin, and other ɑ1-adrenergic antagonists can decrease the tone of the periurethral muscles and promote symptoms of stress incontinence.

Treatment of functional incontinence depends on the cause, and rather than attempting to treat the incontinence, corrective action based on the etiology usually results in resolution of the incontinence symptoms.

Patient Referral

Although the majority of patients with UI can be effectively evaluated and managed by a primary care provider, some patients should be referred to a urologist or urogynecologist for further evaluation. These circumstances include an uncertain diagnosis, lack of treatment response, impaired bladder emptying, the presence of either gross or microscopic hematuria, the presence of a pelvic mass, or very severe symptoms. Patients with spinal cord disease, demyelinating disease, or previous pelvic surgery or radiation also should be referred.

Darryl S. Chutka, MD, is an internist at the Mayo Clinic in Rochester, Minnesota.

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