Definition & Clinical Features
Normally you make a conscious decision about when to empty your bladder. When you get the feeling that your bladder is full, you control the urge to urinate and make it to the toilet facility in time.
Unfortunately, some individuals have an overactive bladder that tries to empty on its own, often without much warning.
If you feel a bladder contraction that causes such a strong sense of urgency that you cannot control it, you may lose urine before you can get to the toilet facility. This is called urge incontinence.
Urge incontinence is the involuntary loss of urine associated with a strong desire to void (urgency) (ICS Committee, 1990, p. 17).
A person with urge incontinence is aware of the need to void, but is unable to prevent the bladder from emptying its contents until toilet facilities are reached.
Two related terms defined by the ICS are unstable detrusor and detrusor hyperflexia.
- An unstable detrusor “is one that is shown objectively to contract, spontaneously or on provocation, during the filling phase while the patient is attempting to inhibit micturition” (ICS Committee, 1990, p. 16).
- Detrusor hyperflexia is defined as “overactivity due to disturbance of the nervous control mechanisms” (ICS Committee, 1990, p. 16). This term is to be used when there is a relevant neurological disorder.
Urge incontinence is usually associated with urinary frequency, urgency, or a complaint such as “I’m unable to make it to the bathroom on time.” At times, urine loss is massive and sudden, occurring with little or no warning at all.
Some women may have urge incontinence when they put their hands in running water or hear water running. Some note urge incontinence when they change position rapidly, such as when they get up quickly from a chair. Others get urge incontinence when they return home with a full bladder, park the car, rush to the front door, and put the key in the door. The anticipation of relief triggers a bladder spasm. This is so common it has a name, “Key-in-the-door incontinenceOpens in new window.”
Women with urge incontinence report that it affects the quality of their lives more than do women who have stress incontinence, depression, or even diabetes.
Urge incontinence often results in a larger amount of lost urine than stress incontinence and is often unpredictable. While you may be able to brace yourself when you are about to laugh or cough and prevent loss of urine from stress incontinence, there is little warning with urge incontinence. By the time you realize what is happening, it is too late. Hence, women with this problem are often subject to embarrassing accidents.
Cause of Urge Incontinence: Detrusor Overactivity
Urge incontinence is caused by an overactive detrusor. It is either idiopathic or secondary to bladder outlet obstruction (detrusor instability), urinary tract infection or bladder cancer.
- Detrusor overactivity is characterized by spontaneous contraction of the detrusor muscle during bladder filling (Resnick & Yalla 1997).
- Urgency is a warning of a few seconds to a few minutes, of the need to urinate. This is classified as motor urgency in patients with cystometrically confirmed overactive detrusor function, or as a sensory urgency in patients with detrusor hypersensitivity, without detrusor contractions during bladder filling.
Frequency is regular day-time and night-time emptying of the bladder before it is full. This symptom, directed by urgency, is due to a reduced functional capacity of the bladder. In part, it is a coping strategy adopted by patients to prevent leakage of large volumes of urine by maintaining small urinary volumes in the bladder. Thus, in an attempt to maintain continence, patients with detrusor overactivity will generally micuturate at least eight times during the day.
Overactive urge incontinence is the most troublesome and upsetting symptom of detrusor overactivity and is reported by approximately 20 percent of men and 40 percent of women with symptoms of detrusor overactivity per se (Feneley 1979; Iarvis 1993); hence, the symptom does not manifest in all patients with detrusor overactivity.
Overactive urge incontinence occurs more often in women than men: indeed, among non-institutionalized populations, approximately 10–22.5 percent of women and more than 7 percent of men experience the disorder. Such gender differences have been attributed to factors such as childbirth and menopausal status (A Report of the Royal College of Physicians 1995; Wall 1990).
Thus, although stress incontinence Opens in new window is the most common form of urinary incontinence in women, urge incontinence due to detrusor overactivity is the most common type of incontinence encountered in elderly women and, overall, it is the second most common form of female urinary incontinence (Eckford & Keane 1993).
Treatment for Urge Incontinence
There are a number of both non-pharmacological and pharmacological measures available for the treatment of urge incontinence. Table 1.1 summaries some of the current treatment approaches for urge incontinence. An important aspect shown in this Table is the use of conservative behavioral intervention, such as pelvic floor exercise training (with or without biofeedback), and systematic bladder training to encourage expulsion of increased volumes of urine at increased intervals (Wall 1997; Abrams 1993).
|Treatment approach||Management options|
The mainstay of treatment for the overactive (unstable) bladder rests primarily on drug therapies, which are designed to abolish the involuntary bladder contractions that cause the patient to urinate uncontrollably. Oxybutynin, which possesses both spasmolytic and anticholinergic properties (Norton et al 1994; Nishizawa 1997), is currently the most widely used agent for the treatment of detrusor overactivity.