Office Evaluation of Overactive Bladder: 4 Easy Steps
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■ OBGMANAGEMENT BY MICKEY KARRAM, MD, and STEVE KLEEMAN, MD Office evaluation of overactive bladder: 4 easy steps Urgency, frequency, and urge incontinence can usually be diagnosed and managed without sophisticated urodynamic testing. 66-year-old woman complains of uri- Revised terminology nary urgency, frequency, and inconti- ne of the most notable changes in the Anence, and estimates that she voids 15 Oterms used to describe lower urinary tract or more times within a typical 24-hour period. dysfunction, proposed by the International So far, she has lost only small amounts of Continence Society,3 is organization of the ter- urine—because she hurries to void at the first minology into 3 categories: symptoms, signs, sense of urgency—but she is distressed and and urodynamic observations. worried that she will have a major accident. Symptoms are now defined to more closely Sound familiar? Overactive bladder affects 17 reflect the way the patient perceives her to 33 million US women.1 Thanks to greater problem, and are set forth without specifying awareness and openness, more women today are the volume of urine required for a diagnosis of seeking medical help for their troubling symptoms, “abnormal” sensation or urgency. although only a fraction have done so up to now.2 Signs can be observed by the physician, such Ob/Gyns who are prepared to quickly evaluate the as leakage of urine when the patient coughs. problem and initiate effective management can Urodynamic observations are made dur- help restore the quality of life these patients ing urodynamic studies. enjoyed before onset of symptoms. This article: Overall, the new and revised terms are • reviews the pathophysiology of “overactive relatively vague to allow for patient-to-patient bladder”; variability. Here are a few examples: • describes a 4-step evaluation and manage- • Overactive bladder is a syndrome of ment routine that should be feasible for any symptoms that suggest dysfunction of the gynecology office setting; lower urinary tract. It is characterized by • discusses the action and the efficacy of available and forthcoming drugs; • uses newly revised terminology that reflects 4- STEP EVALUATION AND MANAGEMENT greater sensitivity to the patient. 1 Ask the right questions, get voiding diary, assess quality of life. ■ Dr. Karram is director of urogynecology at Good Samaritan Hospital in Cincinnati, Ohio, and professor of obstetrics and 2 Perform ‘eyeball’ cystometry. gynecology at the University of Cincinnati. Dr. Kleeman is assistant director of the division of urogynecology and recon- 3 Conduct a thorough physical assessment. structive surgery at Good Samaritan Hospital in Cincinnati. 4 Begin bladder retraining, pelvic floor muscle December 2003 • OBG MANAGEMENT 17 rehabilitation, and appropriate medical therapy. urgency with or without urge incontinence, Sensory urgency is a strong, uncomfortable usually involving frequency and nocturia. need to void without fear of impending leak- • Urinary incontinence is any involuntary age; for whatever reason, the bladder has leakage of urine. become hypersensitive. Delaying voiding may • Daytime frequency. The patient feels she result in pain but rarely leads to incontinence. voids more frequently than she should during Patients with motor urgency urinate fre- the day. quently because they are afraid of experiencing • Nocturia. The patient wakes 1 or more a complete or partial involuntary void as a times at night to void. result of an involuntary bladder contraction. • Urgency. The patient feels a sudden, com- pelling desire to pass urine. How the normal bladder functions • Urge urinary incontinence is involun- he process of bladder storage and evacua- tary leakage accompanied by or immediately Ttion can be visualized as a complex of preceded by urgency. neurocircuits in the brain and spinal cord that • Bladder sensation is identified during coordinate the activity of smooth muscle in history taking: normal, increased, reduced, the bladder and urethra (FIGURE). These cir- absent, and nonspecific. cuits act as “on/off ” switches in the lower uri- • Detrusor overactivity replaces the term nary tract, alternating between the 2 modes of “detrusor instability” or “hyperreflexia.” It is operation: storage and elimination. a urodynamic observation characterized by As the bladder gradually fills with urine, involuntary detrusor contractions during the a woman initially perceives a first sensation filling phase, and may be spontaneous or of filling between 75 and 125 cc of urine, feels provoked. It may be further qualified as the first need to void at approximately 300 cc, neurogenic (if a neurologic condition under- and reaches maximum capacity and a strong lies the problem) or as idiopathic. urge to void at 400 to 700 cc. Since the bladder is a low-pressure reser- What is abnormal bladder function? voir, intravesical bladder pressure typically ny actual incontinence should be con- rises very little despite increasing amounts of Asidered abnormal, whether diurnal urine and distention of the smooth muscle or or nocturnal. detrusor muscle of the bladder. Pressure Frequency: More than 8 voids in 24 hours. ranges from 2 to 6 cm of water in an empty Although an ordinary voiding pattern is not state and rarely exceeds 10 cm of water at fully defined, most experts agree that a frequen- maximum capacity. cy of 8 or fewer voids in 24 hours is “normal.” At maximum capacity, a woman should be Urgency: Patient’s opinion determines. able to get to the toilet easily, initiate voluntary The sensation of urgency is more difficult to bladder contraction with complete relaxation objectively define; hence, the need to rely on of her pelvic floor, and void to completion. the patient’s perceptions. If a patient is voiding more frequently than normal because she has Urge incontinence is more an uncomfortable, sudden desire to pass urine, detrimental to quality of life she is considered to have urgency. In contrast, a f women who complain of urinary woman who voids frequently because she has Oincontinence, more than 90% have stress incontinence and wants to keep her blad- either loss of detrusor muscle control (urge der as empty as possible to avoid leakage has incontinence) or urethral sphincteric incom- frequency without urgency. Urgency is best petence (stress incontinence).4 In addition, classified as being sensory or motor in nature. 30% to 50% of women with stress inconti- 18 OBG MANAGEMENT • December 2003 Office evaluation of overactive bladder: 4 easy steps FIGURE Bladder relaxation and contraction: An interplay of nerve impulses 1 Signals in the parasympathetic 3 In the sympathetic nervous system, system originate at spinal cord signals exit at spinal cord levels T1 levels S2-S4, traveling to the bladder through L2 and travel to the bladder via the pelvic nerve and binding to via the hypogastric nerve, where muscarinic receptors —specifically noradrenaline is released. Noradrenaline M2 and M3 subtypes. When M3 binds to the beta receptors, causing subtypes are set in motion, they a chain reaction that ultimately causes trigger a chain of events that leads relaxation of the bladder. to muscle contraction. M2 receptor activation ultimately inhibits T10 the relaxation caused by the 3 sympathetic system. T11 hypogastric nerve T12 alpha L2 beta L1 pelvic nerve S2 S3 S4 1 2 The striated muscle of the external pelvic urethral sphincter is innervated by plexus motor neurons that originate in Onuf’s nucleus (located within the sacral spinal cord) and travel via the 2 pudendal nerve. pudendal nerve external urethral sphincter to perineal } muscles and striated distal external anal urogenital sphincter sphincter proximal Image: Birck Cox nence have coexistent urge incontinence.1 only with increases in intraabdominal pres- Urge incontinence has a much more dra- sure associated with exercise, coughing, etc. matic impact on a woman’s quality of life These leakages tend to occur in small spurts than stress incontinence, because stress that are easily absorbed by protective wear. In incontinence is predictable and controllable. contrast, urge incontinence manifests as an The patient understands she will leak urine unpredictable, involuntary void in which December 2003 • OBG MANAGEMENT 19 Office evaluation of overactive bladder: 4 easy steps urine is released in a gushing stream, often in Outlet obstruction can result in urge incon- quantities large enough to soak through tinence such as the well recognized symptoms heavy absorbent pads. of urethral obstruction in men with benign Although one might assume that subjec- prostatic hyperplasia. tive complaints would readily distinguish the Detrusor sphincter dysnergia, most common- 2 conditions, the bladder is a very poor ly secondary to spinal cord injury or multiple “witness.” What the patient perceives often sclerosis, may affect younger men and women. fails to correlate with the true mechanism of A deficient urethral sphincter in women with incontinence. Since therapies for these 2 con- stress incontinence may induce urge inconti- ditions are completely different, the evalua- nence, as urine leaking into the urethra sec- tion of incontinence is very important. ondary to the stress incontinence stimulates In aging women, the prevalence of fre- urethral afferents that induce involuntary quency, urgency, and urge incontinence voiding reflexes.7 is much higher than that of stress inconti- Women with stress incontinence may nence. Among women 60 to 80 years of unwittingly contribute to overactive bladder age—growth-wise, the largest segment of our by voiding more and more often, hoping to population—as many as 50% experience fre- prevent any involuntary urine loss. As a result quency, urgency, and urge incontinence. of the frequent voiding, they develop frequen- High economic cost. The tremendous cy and urgency symptoms. That is, over time, expense of urinary incontinence is increas- this frequent, voluntary voiding leads to ingly recognized. In 1995, for example, the decreased bladder compliance. Thus begins a economic cost in the United States was $26.3 vicious cycle that ultimately leads to more fre- billion, or $3,565 per person 65 years or older quency and urgency.