••• Chapter 39^ Urinary Incontinence and Urodynamics^387
Excessive urine output (eg, from hyperglycemia)
Restricted mobility
Stool impaction❍ What should be included in the basic evaluation of a patient with incontinence?
A detailed history including description of incontinence episodes (including precipitating or preceding events—for
example, urine leakage with exertion suggests genuine stress incontinence, leakage preceded by urgency suggests
OAB), frequency of incontinent episodes, amount of urine loss, intake of bladder irritants (such as caffeine and
alcohol), voiding dysfunction symptoms, pelvic organ prolapse symptoms, prior pelvic surgery or radiation
therapy, current medications and physical examination including neurological evaluation, assessment of urethral
mobility, pelvic floor support, urinalysis with culture if indicated and simple cystometry. For those patients with
any voiding dysfunction symptoms, a postvoid residual should also be obtained.
❍ How is urethral mobility assessed?
The “Q-tip test” is an office-based assessment of urethral mobility (which is a risk factor for stress incontinence).
A cotton swab is placed in the urethra to the level of the vesical neck and the measurement of the axis change with
strain is performed with a goniometer. Hypermobility is defined as a change in angle with Valsalva of >30 degrees.
❍ What is simple cystometry?
Simple cystometry is the evaluation of bladder filling. It examines the pressure-volume relationship during filling.
It is a “single channel” measurement in that only bladder pressure is being measured. It can be done without
urodynamic equipment using a “hand held” system. A 50-mL syringe without its piston or bulb is attached to the
catheter and held above the bladder. The bladder is then gradually filled by gravity in 50-mL increments and the
patient’s first sensation of filling (normal values vary, usually the patient senses this when asked), first sensation of
urgency (normal range 150–250), and maximum bladder capacity (normal 300–500) are noted. Any rise in the
column of water in the syringe may be due to inappropriate bladder contractions (the patient inadvertently bearing
down may also cause this). The standing stress test may then be performed, after the patient’s catheter is removed.
❍ What is the standing stress test and how is it performed?
The cough stress test involves filling a patient’s bladder to at least 300 mL or symptomatic fullness and having
the patient cough while standing when the urethral meatus is visualized. If urine leakage is observed, the test is
positive. This test is an indicator of stress incontinence.
❍ What is intrinsic sphincter deficiency (ISD)?
It is the most severe form of stress urinary incontinence. It is defined by the following urodynamic parameters: leak
point pressure of <60 cm H 2 O and/or maximal urethral closure pressure of <20 cm H 2 O.
❍ How is ISD diagnosed?
By complex multichannel cystometry (urodynamic testing, UDT). GSUI in the absence of urethral hypermobility
(failure of extrinsic support) is most often considered by definition due to ISD. Maximum urethral closure pressure
(MUCP) <20 cm H 2 O and/or Valsalva leak point pressures <60 cm H 2 O. A positive empty stress test (stress test
done after patient has emptied her bladder) is also a sign of ISD.
❍ What are the risk factors for ISD?
Women of advanced age, a history of previous radiation, previous failed incontinence procedure, or spinal cord
injury.