Understanding Overactive Bladder (OAB) In Women
Women's Health & Education Center's Contribution The term Overactive Bladder (OAB) encompasses urinary symptoms such as frequency, urgency, and urge incontinence. This common medical condition is seen in roughly one in five women aged 25-64. The purpose of this document is to help us understand neurology and physiology of overactive bladder and to formulate the best treatment for the patient. 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. 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. Since therapies of stress incontinence and urge incontinence is 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, the largest segment of our population - as many as 50% experience frequency, urgency and urge incontinence. The tremendous expense of urinary incontinence is increasingly recognized. In the United States the direct costs associated with incontinence is estimated at $ 26 Billion per year and approximately 17 million US adults have OAB (1). Medical consequences of OAB can be quite serious: Patients may develop complications such as decubitus ulcers, perineal rashes, cystitis, urinary tract infections, urosepsis, and renal failure. Women with OAB are also at considerable risk for falls and fractures - probably because they are frequently in a hurry to reach the bathroom. Contributing factors and causes of overactive bladder: A potential etiology for OAB is neurological dysfunction stemming from disease or aging and resulting in disruption of the complex control system present in the lower urinary tract. It is thought to be multifactorial. Coexisting conditions may also contribute to symptoms or may even be the sole cause. Examples include: - Injury or diseases of the nervous system: At a local level, urge incontinence can develop secondary to intrinsic detrusor myogenic abnormalities. It disrupts voluntary control of voiding in adults, triggering the reemergence of reflex voiding, which leads to bladder hyperactivity and urge incontinence.
- Outlet obstruction: Urethral obstruction or foreign body in the bladder and in men with benign prostatic hyperplasia can result in urge and frequency of micturition.
- Urinary tract infection or cystitis: Urinary tract infection without associated neurologic or obstructive disorders can resolve after 3 days of antibiotic therapy (course treatment will continue for 1 to 2 weeks). It can resolve the symptoms of urge and frequency.
- 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, urine leakage into the urethra stimulates urethral afferents that can induce involuntary voiding reflexes.
- Urogenital atrophy: Irritative symptoms of lower urinary tract in the form of frequency, urgency, and dysuria can result from lack of estrogen, leading to urogenital atrophy.
- Pelvic organ prolapse: It 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.
- Enlarged uterus or adnexal mass: It may cause external compression of the bladder and lead to lower urinary tract symptoms.
- Previous surgery: The anterior vaginal wall or bladder neck repairs may sometimes trigger de novo symptoms of frequency, urgency, and urge incontinence. In women who have undergone a previous anti-incontinence procedure, these symptoms may be related to some form of outlet obstruction.
Framework for understanding bladder health: Bladder relaxation and contraction: An interplay of nerve impulses
Source: OBG Management; December 2003; Image: Birck Cox
Diagnosis: More specific questions can help to identify the nature of the incontinence, and queries about whether or not patients use pads or other protective devices may also encourage further dialogue. Affirmative answers to direct questions about urine loss associated with an urge to urinate or postvoid dribbling may be suggestive of detrusor instability, the most common cause of OAB symptoms. Discuss about duration and characteristic of urine loss and evaluate severity of the condition; type and number of pads or briefs used daily or weekly, number of incontinent voids and changes in activities of daily living or fluid intake patterns. Query patients about presence of pain, hematuria and infection, and about changes in bowel habits and sexual function. Review of past incontinence management strategies is important to formulate effective treatment plan for the patient. OAB is characterized by urgency, frequency and urge incontinence. Stress incontinence is associated with coughing and exercise. Mixed incontinence is the combination of stress/OAB features. Since these disorders can co-exist, comprehensive evaluation and therapy are absolutely essential. More accurate diagnosis has led to improvement in treatment outcomes and better patient selection for medical and behavioral therapy. Urinary cytology and cystoscopy are recommended in patients with recurrent urinary tract infections and hematuria. Postvoid residual (PVR) should be measured in patients with suprapubic tenderness or distension, diabetes, or neurologic disease, as well as in those taking medications that can interfere with bladder emptying. Determining PVR volume requires catheterization or pelvic ultrasound. Residual volumes of less than 50 mL are generally considered indicative of adequate bladder emptying, whereas repeated residual volumes greater than or equal to 100 to 200 mL usually represent inadequate emptying (2). Urodynamic testing is indicated in the elderly (>75 y), and in patients with an elevated PVR, mixed symptoms of stress and urge incontinence, or unsuccessful surgery for incontinence. These tests include the following: cystometry or urethrocystometry (tests of detrusor storage and contractile function), uroflowmetry or voiding pressure studies (tests of urine flow rate and mechanism), and urethral pressure profilometry (test of resting and dynamic pressures in the urethra). Such specialized tests help to determine the anatomic and functional status of the urethra and bladder, and may be useful in determining the cause of AOB (3). Treatment:
Non-surgical treatments can be non-pharmacologic or pharmacologic. They can be used alone or in combination, depending on the severity of the condition and the patient's ability to comply with treatment. - Non-pharmacologic Therapy
Pelvic floor exercise, Biofeedback, Bladder retraining: For details please review the following link http://www.womenshealthsection.com/content/urog/urog002.php3- Pharmacologic Therapy
Anticholinergic (antimuscarinic) agents treat OAB by limiting uncontrolled contractions of the detrusor muscle. The main problem with these agents is the side effects; dry mouth is the most frequent cause of discontinuation. For details please review the following link: http://www.womenshealthsection.com/content/urog/urog006.php3
Conclusion:Overactive bladder (OAB) is a common medical condition that can erode a woman's psychological and social well-being, and may have serious health consequences if left untreated. Therapy may include non-pharmacologic techniques, medication or a combination. Usefulness of pharmacotherapy may be limited by adverse reactions such as dry mouth, although newer medications such as ER oxybutynin and tolterodine tartrate may have slightly fewer side effects. Appropriate early intervention, which includes identifying the disorder, is a key factor in slowing the progression of detrimental changes in the lower urinary tract. References: - Wagner TH, Hu TW. Economic costs of urinary incontinence in 1995. Urology. 1998;51:355-61.
- Fantl JA, Newman DK, Colling J, et al. Urinary incontinence in adults: acute and chronic management. Clinical Practice Guideline No. 2, 1996 Update. Rockville MD: US Department of Health and Human Services, Public Health Service, Agency for Health Care Policy and Research. March 1996. AHCPR publication no. 96-0682.
- Wein AJ, Rovner ES. The overactive bladder: an overview for primary care health providers. Int J Fertil Womens Med. 1999;44:56-66.
