Overactive bladder; Detrusor instability; Detrusor hyperreflexia; Irritable bladder; Spasmodic bladder; Unstable bladder; Urge incontinence
Urge incontinence involves a strong, sudden need to urinate immediately followed by a bladder contraction, resulting in an involuntary loss of urine.
Causes, incidence, and risk factors
The ability to hold urine and maintain continence is dependent on normal function of the lower urinary tract, the kidneys, and the nervous system - plus the physical and psychological ability to recognize and appropriately respond to the urge to urinate. The bladder’s ability to fill and store urine requires a functional sphincter (muscle controlling output) and a stable bladder wall muscle (detrusor).
The process of urination involves two phases: the filling and storage phase, and the emptying phase.
During the filling and storage phase, the bladder begins to fill, stretching to accommodate the increasing amount of urine. The bladder of an average person can hold 350 mL to 550 mL of urine.
The first sensation of the need to urinate occurs when approximately 200 mL of urine is stored. The nervous system responds by alerting you to the need to urinate while also allowing the bladder to continue to fill.
The emptying phase requires the ability of the detrusor muscle to appropriately contract, forcing urine out of the bladder. The body must also be able to simultaneously relax the sphincter to allow the urine to exit.
The bladder of an infant contracts automatically when a certain volume of urine is collected in the bladder. As the individual learns to control urination, bladder muscle contraction is prevented by constant inhibition from the cerebral cortex (part of the brain). This allows urination to be delayed until the individual is ready.
Undesired bladder muscle contraction may occur as the result of a break in the neurological pathway from the brain to the bladder. It can also occur if the bladder is irritated and the normal neurological impulses to inhibit urination are insufficient to keep the bladder relaxed as it fills.
Urge incontinence is basically a storage problem in which the bladder muscle contracts inappropriately. Often these contractions occur regardless of the amount of urine that is in the bladder. Urge incontinence may result from neurological injuries (such as spinal cord injury or stroke), neurological diseases (such as multiple sclerosis), infection, bladder cancer, bladder stones, bladder inflammation, or bladder outlet obstruction.
The majority of cases are classified as idiopathic - a specific cause cannot be identified.
Although urge incontinence may occur in anyone at any age, it is more common in women and the elderly. It is second only to stress incontinence as the most common cause of urinary incontinence (involuntary loss of urine). Approximately 1% to 2% of adult females are affected by urge incontinence.
In men, urge incontinence may be due to secondary bladder injuries caused by benign prostatic hypertrophy (BPH) or bladder outlet obstruction from an enlarged prostate.
- Sudden and urgent need to urinate (urinary urgency)
- Frequent urination, in the daytime and at night
- Abdominal distention or discomfort
- Involuntary loss of urine
Signs and tests
A physical examination will include examination of the abdomen and rectum. Women will also have a pelvic exam. Men will also have a genital exam. In most cases the physical exam reveals nothing abnormal.
If there are neurologic causes, other neurologic abnormalities may be found.
Tests include the following:
- Post-void residual (PVR) to measure amount of urine left after urination
- Urinalysis or urine culture to rule out urinary tract infection
- Urinary stress test (the patient stands with a full bladder and coughs)
- Pad test (after placement of a pre-weighed sanitary pad, patient exercises, then pad is weighed to determine urine loss)
- Pelvic or abdominal ultrasound
- X-rays with contrast dye
- Cystoscopy (inspection of the inside of the bladder)
- Urodynamic studies (measurement of pressure and urine flow)
- EMG (myogram) - rarely needed
Further tests will be performed to rule out other types of incontinence. These tests may include the “Q-tip test,” which measures the change in the angle of the urethra at rest and when straining. An angle change of greater than 30 degrees often indicates significant weakness of the muscles that support the bladder, which is common in stress incontinence.
There are several different approaches that may be used in managing and treating urge incontinence. If evidence of infection is found in urine culture, antibiotics will be prescribed. The choice of a specific treatment will depend on the severity of the symptoms and the extent that the symptoms interfere with lifestyle. There are three main approaches to treatment: medication, retraining, and surgery.
Medications used to treat urge incontinence are aimed at relaxing the involuntary contraction of the bladder and improving bladder function. There are several types of medications that may be used alone or in combination:
- Anticholinergic agents (propantheline)
- Antispasmodic medications (oxybutynin, tolterodine, flavoxate)
- Tricyclic antidepressants (imipramine, doxepin)
- Calcium channel blockers (tolterodine)
- Beta agonist (terbutaline)
Oxybutynin (Ditropan) and tolterodine (Detrol) are antispasmodic medications that relax the smooth muscle of the bladder. These are the most commonly used medications for urge incontinence and are available in a once-a-day formulation that makes dosing easy and effective.
Side effects of oxybutynin and tolterodine are minimal, with the most common being dry mouth and constipation. However, these medications cannot be used by patients with narrow angle glaucoma.
Dicyclomine (Bentyl) is another antispasmodic medication that relaxes the bladder. Side effects, including dry mouth, dizziness, drowsiness, increased heart rate, and difficulty urinating, are reported in about half of the people who are taking it.
Another antispasmodic drug is flavoxate (Urispas). However, studies have shown inconsistent benefit in controlling symptoms of urge incontinence.
Anticholinergic medications block inappropriate contractions of the bladder. They were widely used in the past to treat urge incontinence because they are relatively inexpensive yet effective. Oxybutynin and tolterodine have virtually replaced the use of these medications because they have fewer side effects.
Tricyclic antidepressants have also been used to treat urge incontinence because of their ability to inhibit or “paralyze” the bladder smooth muscle. Possible side effects include fatigue, dry mouth, dizziness, blurred vision, nausea and insomnia.
The goal of any surgery to treat urge incontinence is aimed at increasing the storage ability of the bladder while decreasing the pressure within the bladder. Surgery is reserved for patients who are severely debilitated by their incontinence and who have an unstable bladder (severe inappropriate contraction) and poor ability to store urine.
Augmentation cystoplasty is the most frequently performed surgical procedure for severe urge incontinence. In this reconstructive surgery, a segment of the bowel is removed and used to replace a portion of the bladder.
Possible complications include those of any major abdominal surgery, including bowel obstruction, blood clots, infection, and pneumonia.
There is a risk of developing urinary fistulae (abnormal tubelike passages that result in abnormal urine drainage), urinary tract infection, and difficulty urinating. Augmentation cytoplasty is also linked to a slightly increased risk of developing tumors.
Some experts recommend a regimen of controlled fluid intake in addition to other therapies in the management of urge incontinence. The goal of this program is to distribute the intake of fluids throughout the course of the day, so the bladder does not need to handle a large volume of urine at one time.
Do not drink large quantities of fluids with meals - limit your intake to less than 8 ounces at one time. Sip small amounts of fluids between meals. Stop drinking fluids approximately two hours before bedtime.
Additionally, it may be helpful to eliminate your intake of foods that may irritate the bladder, such as caffeine, spicy foods, carbonated drinks, and highly acidic foods such as citrus fruits and juices.
Management of urge incontinence usually begins with a program of bladder retraining. Occasionally, electrical stimulation and biofeedback therapy may be used in conjunction with bladder retraining.
A program of bladder retraining involves becoming aware of patterns of incontinence episodes and relearning skills necessary for storage and proper emptying of the bladder. Bladder retraining alone is successful in 75% of people treated for urge incontinence.
Bladder retraining consists of developing a schedule of times when you should try to urinate, while trying to consciously delay urination between these times. One method is to force yourself to wait 1 to 1 1/2 hours between urinations, despite any leakage or urge to urinate in between these times. As you become skilled at waiting, gradually increase the time intervals by 1/2 hour until you are urinating every 3 to 4 hours.
Pelvic muscle training exercises called Kegel exercises are primarily used to treat people with stress incontinence. However, these exercises may also be beneficial in relieving the symptoms of urge incontinence. The principle behind Kegel exercises is to strengthen the muscles of the pelvic floor, thereby improving the urethral sphincter function. The success of Kegel exercises depends on proper technique and adherence to a regular exercise program.
Another approach is to use vaginal cones to strengthen the muscles of pelvic floor. A vaginal cone is a weighted device that is inserted into the vagina. The woman contracts the pelvic floor muscles in an effort to hold the device the place. The contraction should be held for up to 15 minutes and should be performed twice daily. Within 4 to 6 weeks, about 70% of women trying this method had some improvement in their symptoms.
BIOFEEDBACK AND ELECTRICAL STIMULATION
For people who are unsure if they are performing Kegel exercises correctly, biofeedback and electrical stimulation may be used to help identify the correct muscle group to work. Biofeedback is a method of positive reinforcement in which electrodes are placed on the abdomen and the anal area.
Some therapists place a sensor in the vagina (for women) or the anus (for men) to assess contraction of the pelvic floor muscles. A monitor will display a graph showing which muscles are contracting and which are at rest. The therapist can help identify the correct muscles for performing Kegel exercises.
About 75% of people who use biofeedback to enhance performance of Kegel exercises report symptom improvement, with 15% considered cured.
Electrical stimulation involves using low-voltage electric current to stimulate the correct group of muscles. The current may be delivered using an anal or vaginal probe. The electrical stimulation therapy may be performed in the clinic or at home. Treatment sessions usually last 20 minutes and may be performed every 1 to 4 days.
Some clinical studies have shown promising results in treating urge incontinence with electrical stimulation.
People with urge incontinence may find it helpful to avoid activities that irritate the urethra and bladder, such as taking bubble baths or using caustic soaps in the genital area.
Urinary incontinence is a chronic (long-term) problem. Although you may be considered cured by various treatments, you should continue to see your provider to evaluate the progress of your symptoms and monitor for possible complications of treatment.
Symptoms can usually be alleviated with accurate diagnosis and adequate treatment regimens. Many patients must try many different therapies or multiple simultaneous therapies to alleviate symptoms. This requires a good working relationship with your doctor.
Instant improvement is unusual. Perseverance and patience are usually required to see improvement. A small number of patients are not helped by conservative medical therapies, and require surgical intervention.
Physical complications are rare, but psychosocial problems may arise, particularly if incontinence results from an inability to get to the bathroom when urgency arises.
Calling your health care provider
If symptoms are moderate or severe (incontinence occurs often, not on rare occasions), or if pelvic discomfort or burning with urination occurs or if symptoms occur daily, call your provider.
Early initiation of bladder retraining techniques may be useful in reducing the severity of symptoms.
by Sharon M. Smith, M.D.
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.