Functional: Urodynamics: Difference between revisions
Urology4all (talk | contribs) Created page with "'''See 2019 CUA NLUTD Guideline Notes, 2017 CUA OAB Guideline Notes, and 2019 AUA OAB Guidelines''' == Terminology == * '''Physiologic filling rate (mL/min): filling rate < predicted maximum (body weight (kg)/4)''' * Non-physiologic filling rate: filling rate > predicted maximum * Cystometrography (CMG): method by which the pressure/volume relationship of the bladder is measured during filling ** '''The detrusor pressure is calculated indirectly by measuring the total..." |
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== Terminology == | == Terminology == | ||
* '''Physiologic filling rate (mL/min): filling rate < predicted maximum (body weight (kg)/4)''' | * '''<span style="color:#ff0000">Physiologic filling rate (mL/min): filling rate < predicted maximum (body weight (kg)/4)</span>''' | ||
* Non-physiologic filling rate: filling rate > predicted maximum | * Non-physiologic filling rate: filling rate > predicted maximum | ||
* Cystometrography (CMG): method by which the pressure/volume relationship of the bladder is measured during filling | * Cystometrography (CMG): method by which the pressure/volume relationship of the bladder is measured during filling | ||
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== Role of Urodynamics (UDS) == | == Role of Urodynamics (UDS) == | ||
* '''Potentially dangerous UDS findings that usually require intervention to prevent upper and lower urinary tract decompensation (6):''' | * '''<span style="color:#ff0000">Potentially dangerous UDS findings that usually require intervention to prevent upper and lower urinary tract decompensation (6):</span>''' | ||
*# '''Impaired compliance''' | *# '''<span style="color:#ff0000">Impaired compliance</span>''' | ||
*# '''Detrusor external sphincter dyssynergia (DESD)''' | *# '''<span style="color:#ff0000">Detrusor external sphincter dyssynergia (DESD)</span>''' | ||
*# '''Detrusor internal sphincter dyssynergia (DISD)''' | *# '''<span style="color:#ff0000">Detrusor internal sphincter dyssynergia (DISD)</span>''' | ||
*# '''Detrusor leak point pressure >40 cm H2O''' | *# '''<span style="color:#ff0000">Detrusor leak point pressure >40 cm H2O</span>''' | ||
*# '''High-pressure detrusor overactivity present throughout filling''' | *# '''<span style="color:#ff0000">High-pressure detrusor overactivity present throughout filling</span>''' | ||
*# '''Poor emptying with high storage pressures''' | *# '''<span style="color:#ff0000">Poor emptying with high storage pressures</span>''' | ||
== Analysis and interpretation == | == Analysis and interpretation == | ||
* '''Each phase is described separately''' | * '''<span style="color:#ff0000">Each phase is described separately</span>''' | ||
** '''Filling/storage phase:''' consists primarily of CMG and provocative testing (e.g. measurement of abdominal leak point pressure, and urethral pressure measurement during storage) | ** '''<span style="color:#ff0000">Filling/storage phase:</span>''' consists primarily of CMG and provocative testing (e.g. measurement of abdominal leak point pressure, and urethral pressure measurement during storage) | ||
** '''Voiding phase:''' evaluates bladder contractility, bladder outlet resistance, and sphincter coordination by pressure-flow analysis and EMG | ** '''<span style="color:#ff0000">Voiding phase:</span>''' evaluates bladder contractility, bladder outlet resistance, and sphincter coordination by pressure-flow analysis and EMG | ||
* '''The 9 Cs of Pressure-Flow UDS'''§ | * '''<span style="color:#ff0000">The 9 Cs of Pressure-Flow UDS</span>'''§ | ||
** '''Filling and storage''' | ** '''Filling and storage''' | ||
**# '''Contractions (involuntary detrusor)''' | **# '''Contractions (involuntary detrusor)''' | ||
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*** '''Failure to demonstrate DO does not rule out its existence.''' | *** '''Failure to demonstrate DO does not rule out its existence.''' | ||
**** Detection can be influenced by the patient’s position. | **** Detection can be influenced by the patient’s position. | ||
* '''Compliance''' | * '''<span style="color:#ff0000">Compliance</span>''' | ||
** '''Definition: compliance is change in bladder volume divided by change in Pdet (∆volume/∆pressure)''' | ** '''<span style="color:#ff0000">Definition: compliance is change in bladder volume divided by change in Pdet (∆volume/∆pressure)</span>''' | ||
** Measured in mL/cm H2O | ** Measured in mL/cm H2O | ||
** Difficult to define normal compliance, but '''normal considered 46-124 mL/cm H2O''' | ** Difficult to define normal compliance, but '''normal considered 46-124 mL/cm H2O''' | ||
** '''See Figure of low compliance on UDS''' | ** '''See Figure of low compliance on UDS''' | ||
** '''Causes of impaired compliance:''' | ** '''<span style="color:#ff0000">Causes of impaired compliance:</span>''' | ||
**# '''Neurologic conditions''' (spinal cord injury, spina bifida) | **# '''<span style="color:#ff0000">Neurologic conditions</span>''' (spinal cord injury, spina bifida) | ||
**#* Usually results from increased outlet resistance (e.g. detrusor external sphincter dyssynergia or decentralization in the case of lower motor neuron lesions | **#* Usually results from increased outlet resistance (e.g. detrusor external sphincter dyssynergia or decentralization in the case of lower motor neuron lesions | ||
**# '''Long-term bladder outlet obstruction''' | **# '''<span style="color:#ff0000">Long-term bladder outlet obstruction</span>''' | ||
**# '''Radiation cystitis''' | **# '''<span style="color:#ff0000">Radiation cystitis</span>''' | ||
**# '''Tuberculosis''' | **# '''<span style="color:#ff0000">Tuberculosis</span>''' | ||
** '''Causes of false-positive:''' | ** '''Causes of false-positive:''' | ||
*** '''Rapid filling''' | *** '''Rapid filling''' | ||
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*** '''“Pop-off mechanisms”, such as vesicoureteral reflux and bladder diverticulae, can make compliance seem higher than it actually is''' | *** '''“Pop-off mechanisms”, such as vesicoureteral reflux and bladder diverticulae, can make compliance seem higher than it actually is''' | ||
** '''Absolute pressure is more useful than a compliance value; storage pressure > 40 cm H2O is associated with harmful effects on the upper tract''' | ** '''Absolute pressure is more useful than a compliance value; storage pressure > 40 cm H2O is associated with harmful effects on the upper tract''' | ||
* '''Continence''' | * '''<span style="color:#ff0000">Continence</span>''' | ||
** '''Leak point pressures''' | ** '''<span style="color:#ff0000">Leak point pressures</span>''' | ||
*** '''2 distinct types of leak point pressures can be measured in the incontinent patient:''' | *** '''<span style="color:#ff0000">2 distinct types of leak point pressures can be measured in the incontinent patient:</span>''' | ||
***# '''Abdominal leak point pressure''' | ***# '''<span style="color:#ff0000">Abdominal leak point pressure</span>''' | ||
***# '''Detrusor leak point pressure''' | ***# '''<span style="color:#ff0000">Detrusor leak point pressure</span>''' | ||
*** '''The ALPP measures the sphincter response to increased Pabd.''' | *** '''<span style="color:#ff0000">The ALPP measures the sphincter response to increased Pabd.</span>''' | ||
**** '''The lower the ALPP, the weaker the sphincter.''' | **** '''<span style="color:#ff0000">The lower the ALPP, the weaker the sphincter.</span>''' | ||
*** '''The DLPP measures the injured bladder response to increased outlet resistance.''' | *** '''<span style="color:#ff0000">The DLPP measures the injured bladder response to increased outlet resistance.</span>''' | ||
**** '''The higher the resistance (e.g. DESD), the higher the DLPP, which is potentially dangerous to upper tracts.''' | **** '''<span style="color:#ff0000">The higher the resistance (e.g. DESD), the higher the DLPP, which is potentially dangerous to upper tracts.</span>''' | ||
*** '''Abdominal leak point pressure (ALPP)''' | *** '''<span style="color:#ff0000">Abdominal leak point pressure (ALPP)</span>''' | ||
**** '''Definition:''' | **** '''<span style="color:#ff0000">Definition:</span>''' | ||
****# '''Intravesical pressure (Pves) at which urine leakage occurs''' | ****# '''<span style="color:#ff0000">Intravesical pressure (Pves) at which urine leakage occurs</span>''' | ||
****# '''As a result of increased Pabd''' | ****# '''<span style="color:#ff0000">As a result of increased Pabd</span>''' | ||
****# '''In the absence of a detrusor contraction''' | ****# '''<span style="color:#ff0000">In the absence of a detrusor contraction</span>''' | ||
****#* '''i.e. how much abdominal pressure transmitted to the bladder results in SUI?''' | ****#* '''i.e. how much abdominal pressure transmitted to the bladder results in SUI?''' | ||
**** '''Measure of the sphincteric strength or the ability of the sphincter to resist changes in Pabd''' | **** '''Measure of the sphincteric strength or the ability of the sphincter to resist changes in Pabd''' | ||
***** '''Applicable to patients with SUI and can only be demonstrated in patients with SUI''' | ***** '''Applicable to patients with SUI and can only be demonstrated in patients with SUI''' | ||
****** '''There is no normal ALPP because patients without SUI will not leak at any physiologic Pabd.''' | ****** '''There is no normal ALPP because patients without SUI will not leak at any physiologic Pabd.''' | ||
****** '''The lower the ALPP, the weaker the sphincter.''' | ****** '''<span style="color:#ff0000">The lower the ALPP, the weaker the sphincter.</span>''' | ||
******* '''ALPP < 60cm H2O: suggestive of intrinsic sphincter deficiency (ISD)''' | ******* '''<span style="color:#ff0000">ALPP < 60cm H2O: suggestive of intrinsic sphincter deficiency (ISD)</span>''' | ||
******* ALPP between 60-90 is equivocal. | ******* ALPP between 60-90 is equivocal. | ||
******* '''ALPP > 90 indicates little or no ISD''' | ******* '''<span style="color:#ff0000">ALPP > 90 indicates little or no ISD</span>''' | ||
**** '''Should be measured as the total Pabd required to cause leakage, not the change in pressure.''' '''The reading is taken from the Pves channel''' as long as there is no involuntary contraction. | **** '''Should be measured as the total Pabd required to cause leakage, not the change in pressure.''' '''The reading is taken from the Pves channel''' as long as there is no involuntary contraction. | ||
**** '''Current technology does not permit a method to distinguish between ISD and urethral hypermobility in women.''' | **** '''Current technology does not permit a method to distinguish between ISD and urethral hypermobility in women.''' | ||
***** '''If there is no urethral hypermobility, SUI must be caused by ISD, regardless of the ALPP. Thus,''' '''an isolated measure of ALPP without considering other factors such as CMG and urethral mobility is of limited utility in predicting success for commonly performed female SUI procedures.''' | ***** '''If there is no urethral hypermobility, SUI must be caused by ISD, regardless of the ALPP. Thus,''' '''an isolated measure of ALPP without considering other factors such as CMG and urethral mobility is of limited utility in predicting success for commonly performed female SUI procedures.''' | ||
**** '''The term ALPP has been used interchangeably with Valsalva leak point pressure; however, this is not entirely correct.''' An ALPP can be measured during UDS testing by a voluntary Valsalva maneuver or by a cough. In the same person, Valsalva leak point pressure tends to be significantly lower than cough leak point pressure. | **** '''The term ALPP has been used interchangeably with Valsalva leak point pressure; however, this is not entirely correct.''' An ALPP can be measured during UDS testing by a voluntary Valsalva maneuver or by a cough. In the same person, Valsalva leak point pressure tends to be significantly lower than cough leak point pressure. | ||
*** '''Detrusor leak point pressure (DLPP):''' | *** '''<span style="color:#ff0000">Detrusor leak point pressure (DLPP):</span>''' | ||
**** '''Definition:''' | **** '''<span style="color:#ff0000">Definition:</span>''' | ||
****# '''The lowest detrusor pressure (Pdet) at which urine leakage occurs''' | ****# '''<span style="color:#ff0000">The lowest detrusor pressure (Pdet) at which urine leakage occurs</span>''' | ||
****# '''In the absence of either increased | ****# '''<span style="color:#ff0000">In the absence of either increased Pabd or a detrusor contraction</span>''' | ||
***** The higher the urethral resistance, the higher the DLPP will be | ***** The higher the urethral resistance, the higher the DLPP will be | ||
**** '''The significance of elevated DLPP is that bladder pressures are getting too high before the pop-off mechanism of urethral leakage occurs.''' | **** '''The significance of elevated DLPP is that bladder pressures are getting too high before the pop-off mechanism of urethral leakage occurs.''' | ||
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****# Non-neurogenic patients with low bladder compliance (after multiple bladder surgeries, radiation, tuberculous cystitis). | ****# Non-neurogenic patients with low bladder compliance (after multiple bladder surgeries, radiation, tuberculous cystitis). | ||
**** '''Higher DLPP is associated with increased risk of upper tract injury as intravesical pressure is transferred to the kidneys.''' | **** '''Higher DLPP is associated with increased risk of upper tract injury as intravesical pressure is transferred to the kidneys.''' | ||
***** '''When treating impaired compliance, concept is to aim for as low a pressure as is reasonably achievable, which would be considerably < 40cm H2O.''' | ***** '''<span style="color:#ff0000">When treating impaired compliance, concept is to aim for as low a pressure as is reasonably achievable, which would be considerably < 40cm H2O.</span>''' | ||
== Voiding and Emptying phase == | == Voiding and Emptying phase == | ||