Clinical Consult

Each month, questions with a common theme will be selected and answered comprehensively by one of our Steering Committee members. Previously answered questions will be archived each month for your reference. If you wish to submit a question, click here.

This Month's Question:

Stress urinary incontinence (SUI) can be caused by a combination of physiologic and transient causes. What are the possible causes of SUI, and how can they be managed effectively?

Response by Mikel L. Gray, PhD, CCCN, CUNP, FAAN, posted 12/06/2005:

Urinary incontinence generally falls into 3 categories: SUI, urge urinary incontinence (UUI), and mixed urinary incontinence (mixed UI). SUI is involuntary urine loss caused by an increase in abdominal pressure seen with coughing, sneezing, or physical activity.¹ SUI arises from 1 of 2 causes: urethral sphincter incompetence, which may result from congenital defects, iatrogenic defects, and/or trauma; or descent of the bladder base with urethral hypermobility due to weakened pelvic floor muscles or damage to the endopelvic fascia.¹

UUI, part of the overactive bladder syndrome, is caused by detrusor overactivity and characterized by the involuntary loss of urine associated with a strong desire to void (urgency).⁴ Mixed UI is not unusual and presents as a combination of SUI and UUI.

Determining whether urinary incontinence is chronic or transient is important because it provides clues to the underlying cause of urine loss and helps guide treatment.¹ Chronic, or established, urinary incontinence usually has an insidious onset and may be present for months or years before the patient seeks help. It reflects a defect or acquired disorder that directly affects lower urinary tract function.²

Transient, or acute, urinary incontinence is characterized by sudden onset.¹ It is typically associated with a systemic disease or disorder that indirectly compromises continence, often by interfering with the person’s ability to perceive and act on cues to urinate or to physically move to the toilet.³ Common causes of transient incontinence include delirium, urinary tract infection, polyuria due to diabetes mellitus or insipidus, restricted mobility, and severe constipation or fecal impaction.³ When diagnosing SUI, evaluations must be comprehensive, focusing not only on the lower urinary tract but also on the patient’s general medical, cognitive, and functional status.³

The management of transient urinary incontinence focuses on treating the underlying problem. For example, transient SUI may be caused or exacerbated by administration of 2 classes of antihypertensive medications, angiotensin-converting enzyme (ACE) inhibitors, or a-adrenergic blocking agents.¹ ACE inhibitors may lead to transient SUI, when it is associated with a chronic cough.¹ Alternatively, a-adrenergic blocking agents lead to SUI by relaxing smooth muscle at the bladder neck and proximal urethra, thus diminishing urethral closure in response to increases in abdominal pressure.¹

Options for managing established SUI can be categorized as behavioral, mechanical, pharmacologic, and surgical.¹ Available behavioral therapies include pelvic floor muscle training (PFMT). PFMT is a 3-step process.¹  Initially, the patient is taught to identify and isolate pelvic floor muscle contraction from distant muscle groups, such as the abdominal or gluteal muscles.¹ Pelvic floor muscle identification may involve formalized biofeedback, using a computer designed to provide visual and/or audible feedback, or it may be taught by palpation and verbal feedback.¹ The second phase, muscle training, focuses on a graded strength program of exercises (Kegel exercises) that improve pelvic floor muscle function, strength, and tone.¹ The third phase of the program, neuromuscular reeducation or skill training, emphasizes teaching the patient when to contract the pelvic floor muscles to maximize continence.^1,3

Mechanical treatment options include urethral inserts or pessaries.^4,5 Pharmacologic treatment plans for SUI have recently focused on research involving 2 neurotransmitters, serotonin and norepinephrine. Increasing levels of serotonin and norepinephrine can lead to increased contraction of the external urethral sphincter.⁶ Duloxetine, a new medication that is a balanced and potent inhibitor of serotonin and norepinephrine reuptake, has been shown in clinical trials to reduce the number of SUI episodes.⁷

Surgical options include suburethral slings using autologous or cadaveric fascia or a synthetic material, open surgery, or injection of bulking materials, such as bovine collagen or silicone beads, into the suburethral mucosa.^1,8 Surgical options are indicated for patients with significant pelvic organ prolapse or when more conservative therapies fail to adequately relieve urinary incontinence.⁹

Therefore, diagnosis and treatment of SUI should be made only after careful consideration of all the possible physiologic and transient causes of SUI.⁹

References

1. Gray M. Stress urinary incontinence in women. J Am Acad Nurse Pract. 2004;16:188-197.

2. Sampselle CM. Behavioral intervention: the first-line treatment for women with urinary incontinence. Curr Urol Rep. 2003;4:356-361.

3. Doughty DB. Promoting continence: simple strategies with major impact. Ostomy Wound Manage. 2003;49:46-52.

4. Newman DK, Giovannini D. The overactive bladder: a nursing perspective. Am J Nurs. 2002;102:36-45.

5. Culligan PJ, Heit M. Urinary incontinence in women: evaluation and management. Am Fam Physician. 2000;62:2433-2444,2447,2452.

6. Newman DK. Stress urinary incontinence in women. Am J Nurs. 2003;103:46-55.

7. Dmochowski RR, Miklos JR, Norton PA, Zinner NR, Yalcin I, Bump RC, for the Duloxetine Urinary Incontinence Study Group. Duloxetine versus placebo for the treatment of North American women with stress urinary incontinence. J Urol. 2003;170:1259-1263.

8. Kassardjian ZG. Sling procedures for urinary incontinence in women. BJU Int. 2004;93:665-670.

9. Holroyd-Leduc JM, Straus SE. Management of urinary incontinence in women. JAMA. 2004;291:986-995.