Office evaluation of overactive bladder: 4 easy steps
Urgency, frequency, and urge incontinence can usually be diagnosed and managed without sophisticated urodynamic testing.
A 66-year-old woman complains of urinary urgency, frequency, and incontinence, and estimates that she voids 15 or more times within a typical 24-hour period. So far, she has lost only small amounts of urine—because she hurries to void at the first sense of urgency—but she is distressed and worried that she will have a major accident.
Sound familiar? Overactive bladder affects 17 to 33 million US women.1 Thanks to greater awareness and openness, more women today are seeking medical help for their troubling symptoms, although only a fraction have done so up to now.2 Ob/Gyns who are prepared to quickly evaluate the problem and initiate effective management can help restore the quality of life these patients enjoyed before onset of symptoms. This article:
- reviews the pathophysiology of “overactive bladder”
- describes a 4-step evaluation and management routine that should be feasible for any gynecology office setting;
- discusses the action and the efficacy of available and forthcoming drugs;
- uses newly revised terminology that reflects greater sensitivity to the patient.
4-STEP EVALUATION AND MANAGEMENT
- Ask the right questions, get voiding diary, assess quality of life.
- Perform ‘eyeball’ cystometry.
- Conduct a thorough physical assessment.
- Begin bladder retraining, pelvic floor muscle rehabilitation, and appropriate medical therapy.
One of the most notable changes in the terms used to describe lower urinary tract dysfunction, proposed by the International Continence Society,3 is organization of the terminology into 3 categories: symptoms, signs, and urodynamic observations.
Symptoms are now defined to more closely reflect the way the patient perceives her problem, and are set forth without specifying the volume of urine required for a diagnosis of “abnormal” sensation or urgency.
Signs can be observed by the physician, such as leakage of urine when the patient coughs.
Urodynamic observations are made during urodynamic studies.
Overall, the new and revised terms are relatively vague to allow for patient-to-patient variability. Here are a few examples:
- Overactive bladder is a syndrome of symptoms that suggest dysfunction of the lower urinary tract. It is characterized by urgency with or without urge incontinence, usually involving frequency and nocturia.
- Urinary incontinence is any involuntary leakage of urine.
- Daytime frequency. The patient feels she voids more frequently than she should during the day.
- Nocturia. The patient wakes 1 or more times at night to void.
- Urgency. The patient feels a sudden, compelling desire to pass urine.
- Urge urinary incontinence is involuntary leakage accompanied by or immediately preceded by urgency.
- Bladder sensation is identified during history taking: normal, increased, reduced, absent, and nonspecific.
- Detrusor overactivity replaces the term “detrusor instability” or “hyperreflexia.” It is a urodynamic observation characterized by involuntary detrusor contractions during the filling phase, and may be spontaneous or provoked. It may be further qualified as neurogenic (if a neurologic condition underlies the problem) or as idiopathic.
What is abnormal bladder function?
Any actual incontinence should be considered abnormal, whether diurnal or nocturnal.
Frequency: More than 8 voids in 24 hours. Although an ordinary voiding pattern is not fully defined, most experts agree that a frequency of 8 or fewer voids in 24 hours is “normal.”
Urgency: Patient’s opinion determines. The sensation of urgency is more difficult to objectively define; hence, the need to rely on the patient’s perceptions. If a patient is voiding more frequently than normal because she has an uncomfortable, sudden desire to pass urine, she is considered to have urgency. In contrast, a woman who voids frequently because she has stress incontinence and wants to keep her bladder as empty as possible to avoid leakage has frequency without urgency. Urgency is best classified as being sensory or motor in nature.
- Sensory urgency is a strong, uncomfortable need to void without fear of impending leakage; for whatever reason, the bladder has become hypersensitive. Delaying voiding may result in pain but rarely leads to incontinence.
- Patients with motor urgency urinate frequently because they are afraid of experiencing a complete or partial involuntary void as a result of an involuntary bladder contraction.
How the normal bladder functions
The process of bladder storage and evacuation can be visualized as a complex of neurocircuits in the brain and spinal cord that coordinate the activity of smooth muscle in the bladder and urethra (FIGURE). These circuits act as “on/off” switches in the lower urinary tract, alternating between the 2 modes of operation: storage and elimination.
As the bladder gradually fills with urine, a woman initially perceives a first sensation of filling between 75 and 125 cc of urine, feels the first need to void at approximately 300 cc, and reaches maximum capacity and a strong urge to void at 400 to 700 cc.
Since the bladder is a low-pressure reservoir, intravesical bladder pressure typically rises very little despite increasing amounts of urine and distention of the smooth muscle or detrusor muscle of the bladder. Pressure ranges from 2 to 6 cm of water in an empty state and rarely exceeds 10 cm of water at maximum capacity.
At maximum capacity, a woman should be able to get to the toilet easily, initiate voluntary bladder contraction with complete relaxation of her pelvic floor, and void to completion.
Urge incontinence is more detrimental to quality of life
Of women who complain of urinary incontinence, more than 90% have either loss of detrusor muscle control (urge incontinence) or urethral sphincteric incompetence (stress incontinence).4 In addition, 30% to 50% of women with stress incontinence have coexistent urge incontinence. 1
Urge incontinence has a much more dramatic impact on a woman’s quality of life than stress incontinence, because stress incontinence is predictable and controllable. The patient understands she will leak urine only with increases in intraabdominal pressure associated with exercise, coughing, etc. These leakages tend to occur in small spurts that are easily absorbed by protective wear. In contrast, urge incontinence manifests as an unpredictable, involuntary void in which urine is released in a gushing stream, often in quantities large enough to soak through heavy absorbent pads.
Although one might assume that subjective complaints would readily distinguish the 2 conditions, the bladder is a very poor “witness.” What the patient perceives often fails to correlate with the true mechanism of incontinence. Since therapies for these 2 conditions are completely different, the evaluation of incontinence is very important.
In aging women, the prevalence of frequency, urgency, and urge incontinence is much higher than that of stress incontinence. Among women 60 to 80 years of age—growth-wise, the largest segment of our population—as many as 50% experience frequency, urgency, and urge incontinence.
High economic cost. The tremendous expense of urinary incontinence is increasingly recognized. In 1995, for example, the economic cost in the United States was $26.3 billion, or $3,565 per person 65 years or older with the condition.5,6 Of these resources, 48%, or $12.53 billion, were drawn directly from the economy to diagnose, treat, care for, and rehabilitate patients with incontinence.
Contributing factors and causes of overactive bladder
Overactive bladder is thought to be multifactorial. Symptoms often occur in the absence of any obvious pathology, which makes it difficult to pinpoint a cause. Coexisting conditions may also contribute to symptoms or may even be the sole cause.
Examples include infection or inflammation of the lower urinary tract, such as a simple case of cystitis, or a foreign body in the bladder.
Injury or diseases of the nervous system can disrupt voluntary control of voiding in adults, triggering the reemergence of reflex voiding, which leads to bladder hyperactivity and urge incontinence. At a local level, urge incontinence can develop secondary to intrinsic detrusor myogenic abnormalities.
Outlet obstruction can result in urge incontinence such as the well recognized symptoms of urethral obstruction in men with benign prostatic hyperplasia.
Detrusor sphincter dysnergia, most commonly secondary to spinal cord injury or multiple sclerosis, may affect younger men and women.
A deficient urethral sphincter in women with stress incontinence may induce urge incontinence, as urine leaking into the urethra secondary to the stress incontinence stimulates urethral afferents that induce involuntary voiding reflexes.7
Women with stress incontinence may unwittingly contribute to overactive bladder by voiding more and more often, hoping to prevent any involuntary urine loss. As a result of the frequent voiding, they develop frequency and urgency symptoms. That is, over time, this frequent, voluntary voiding leads to decreased bladder compliance. Thus begins a vicious cycle that ultimately leads to more frequency and urgency.
Urogenital atrophy. Irritative symptoms of the lower urinary tract in the form of frequency, urgency, and dysuria can result from lack of estrogen, leading to urogenital atrophy.
Pelvic organ prolapse is another common coexisting condition. Although the correlation between anatomic descent of pelvic organs and lower urinary tract symptoms is poorly understood, frequency and urgency—with or without urge incontinence—coexist with symptomatic pelvic organ prolapse in approximately 30% to 50% of cases.
An enlarged uterus or adnexal mass may cause external compression of the bladder and lead to lower urinary tract symptoms.
Previous surgery of the anterior vaginal wall or bladder neck may sometimes trigger de novo symptoms of frequency, urgency, and urge incontinence. In women who have undergone a previous antiincontinence procedure, these symptoms may be related to some form of outlet obstruction. In some cases these patients have no increase in the postvoid residual, and only subtle urodynamic testing elicits evidence of obstruction.
Step 1Ask the right questions, get voiding diary, assess quality of life
Most women can be thoroughly evaluated within the clinical practice setting of any gynecologist. The first and most important aspect of this assessment is understanding and appreciating the severity of a patient’s lower urinary tract symptoms. This can be done by asking pointed questions, in the following approximate sequence:
- Do you have problems with accidental loss of urine?
- How many months or years have you had leakage?
- Do you have to wear pads or protective clothing to prevent or help with urinary loss? If so, how many pads do you wear a day?
- How many trips do you make to the bathroom during the day? At night?
- Do you ever wet the bed while sleeping?
- Are you bothered by a strong sense of urgency to void? Can you overcome it?
- Do you sometimes fail to reach the bathroom in time?
- Does the sound, sight, or feel of running water cause you to lose urine?
- Do you lose urine when you cough, sneeze, run, or lift heavy objects?
- Do you lose urine with posture changes, standing, or walking?
- Do you feel as though you are constantly wet?
- Do you feel as though your bladder is completely empty after passing urine?
- Do you have difficulty starting a stream of urine?
Also ask about pelvic organ prolapse, defecatory dysfunction, and sexual dysfunction.
Take a thorough medical history, as well as a surgical history with emphasison previous bladder or gynecologic procedures.
Also review all prescription medications.
48-hour voiding diary. Give the patient a voiding diary to fill out 48 hours prior to her office visit. The reason: The diary often reveals more information than can be elicited from the patient’s history. For example, it may highlight daily activities associated with voiding, such as excessive consumption of liquids, high caffeine intake, high-impact exercise, and so on.
Quality-of-life assessment. An objective means of quantifying the effects of incontinence on the woman’s quality of life is recommended. We use the short form of the Incontinence Impact Questionnaire and the Urinary Distress Inventory.
Step 2Perform ‘eyeball’ cystometry, a simple and revealing office test
Ask the patient to go to the restroom and comfortably empty her bladder into a urine-collection device to determine the amount voided. Have a nurse measure the postvoid residual using a soft red rubber catheter. A sample can be taken for urinalysis and, if necessary, sent for culture.