Chapter 62 Urinary Incontinence: Stress
INTRODUCTION
Description: Urinary incontinence is a sign, a symptom, and a disease all at the same time. Stress incontinence is limited almost exclusively to women. Stress incontinence is the passive loss of urine in response to increased intraabdominal pressure, such as that caused by coughing, laughing, or sneezing.
Prevalence: Stress incontinence affects 10% to 15% of all women and 30% to 60% of women after menopause.
Predominant Age: Mid-reproductive age and onward. Stress incontinence becomes more common during the 40s and beyond and is most common after menopause.
ETIOLOGY AND PATHOGENESIS
Causes: Unequal transmission of intraabdominal pressure to the bladder and urethra. Generally associated with an anatomic defect such as a cystocele, urethrocele, or cystourethrocele. The degree of incontinence is often not correlated with the scale of pelvic relaxation.
DIAGNOSTIC APPROACH
Workup and Evaluation
Laboratory: No evaluation indicated. Urinalysis is generally recommended, although results are nonspecific. Abrupt-onset incontinence in older patients should suggest infection, which may be confirmed through urinalysis or culture.
Imaging: Radiographic studies are sometimes performed as a part of complex urodynamics studies but are generally of limited utility.
Special Tests: A “Q-tip test” is generally recommended, although it as a poor predictive value. (A cotton-tipped applicator dipped in 2% lidocaine [Xylocaine] is placed in the urethra and rotation anteriorly with straining is measured. Greater than 30 degrees is abnormal.) An evaluation of urinary function is advisable, especially if surgical therapy is being considered. In the past, the functional significance of a cystourethrocele was gauged by elevating the bladder neck (using fingers or an instrument) and asking the patient to strain (referred to as a Bonney or Marshall-Marchetti test). This test has fallen out of favor as nonspecific and unreliable.
Diagnostic Procedures: The best way to confirm stress incontinence is by pelvic examination—loss is best demonstrated by having the patient strain or cough while the vaginal opening is observed (preferably while the patient is standing). Urodynamics testing (simple or complex) may be used to evaluate other possible causes of incontinence.
