Disclosures Basic Principles of Urodynamics
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1 Basic Principles of Urodynamics Basic Principles of Urodynamics Andrew Gammie Andrew Gammie with grateful acknowledgement of with grateful acknowledgement of Gordon Hosker Gordon Hosker Bristol Urological Institute, Bristol, UK The Warrell Unit, St Mary’s Hospital, Manchester. UK. Disclosures Disclosures Albyn, Andromeda, Laborie, Mediwatch, MMS Albyn, Andromeda, Laborie, Mediwatch, MMS Project sponsorship Project sponsorship Project sponsorship Project sponsorship T-Doc LLC Doc LLC Trial sponsorship Trial sponsorship Schafer W Schafer W Abrams P Abrams P Liao L Liao L Mattiasson A Mattiasson A Pesce F Pesce F Spangberg A Spangberg A Sterling AM Sterling AM Zinner NR Zinner NR Good Good Urodynamic Urodynamic Practices: Practices: Uroflowmetry Uroflowmetry, , Filling Filling Cystometry Cystometry Zinner NR Zinner NR Van Kerrebroeck P Van Kerrebroeck P Neurourology and Neurourology and Urodynamics Urodynamics 2002 2002 (pp. 261 (pp. 261-274) 274) Filling Filling Cystometry Cystometry , , and Pressure and Pressure-Flow Flow Studies Studies Abrams P Abrams P Cardozo L Cardozo L Fall M Fall M Griffiths D Griffiths D Rosier P Rosier P Ulmsten U Ulmsten U van Kerrebroeck P van Kerrebroeck P Victor A Victor A The The Standardisation Standardisation of Terminology of Terminology of Lower Urinary of Lower Urinary Tract Function Tract Function Victor A Victor A Wein A Wein A Neurourology and Neurourology and Urodynamics Urodynamics 2002 2002 (pp. 167 (pp. 167-178) 178) Tract Function Tract Function Haylen BT Haylen BT De Ridder D De Ridder D Freeman RM Freeman RM Swift SE Swift SE Berghmans B Berghmans B Lee J Lee J Monga A Monga A Petri E Petri E Rizk DE Rizk DE Sand PK Sand PK Schaer GN Schaer GN An International An International Urogynecological Urogynecological Association (IUGA) / Association (IUGA) / International International Continence Society Continence Society (ICS) (ICS) J i tR t th J i tR t th Schaer GN Schaer GN Neurourology and Neurourology and Urodynamics Urodynamics 2010 2010 29 29 (pp. 4 (pp. 4-20) 20) International Urogynecology International Urogynecology Journal Journal 2010 2010 21 21 (pp. 5 (pp. 5-26) 26) Joint Report on the Joint Report on the Terminology for Female Terminology for Female Pelvic Floor Pelvic Floor Dysfunction Dysfunction
Transcript of Disclosures Basic Principles of Urodynamics
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Basic Principles of UrodynamicsBasic Principles of Urodynamics
Andrew GammieAndrew Gammie
with grateful acknowledgement ofwith grateful acknowledgement of
Gordon HoskerGordon Hosker
Bristol Urological Institute, Bristol, UK
The Warrell Unit, St Mary’s Hospital, Manchester. UK.
DisclosuresDisclosures
Albyn, Andromeda, Laborie, Mediwatch, MMSAlbyn, Andromeda, Laborie, Mediwatch, MMSProject sponsorshipProject sponsorshipProject sponsorshipProject sponsorship
TT--Doc LLCDoc LLCTrial sponsorshipTrial sponsorship
Schafer WSchafer WAbrams PAbrams PLiao LLiao LMattiasson AMattiasson APesce FPesce FSpangberg ASpangberg ASterling AMSterling AMZinner NRZinner NR
Good Good Urodynamic Urodynamic Practices:Practices:UroflowmetryUroflowmetry, , FillingFilling CystometryCystometry Zinner NRZinner NR
Van Kerrebroeck PVan Kerrebroeck P
Neurourology and Neurourology and UrodynamicsUrodynamics20022002(pp. 261(pp. 261--274)274)
Filling Filling CystometryCystometry, , and Pressureand Pressure--Flow Flow StudiesStudies
Abrams PAbrams PCardozo LCardozo LFall MFall MGriffiths DGriffiths DRosier PRosier PUlmsten UUlmsten Uvan Kerrebroeck Pvan Kerrebroeck PVictor AVictor A
The The Standardisation Standardisation of Terminology of Terminology of Lower Urinary of Lower Urinary Tract FunctionTract Function Victor AVictor A
Wein AWein A
Neurourology and Neurourology and UrodynamicsUrodynamics20022002(pp. 167(pp. 167--178)178)
Tract FunctionTract Function
Haylen BT Haylen BT De Ridder D De Ridder D Freeman RMFreeman RMSwift SESwift SEBerghmans BBerghmans BLee JLee JMonga AMonga APetri EPetri ERizk DERizk DESand PKSand PKSchaer GNSchaer GN
An International An International UrogynecologicalUrogynecologicalAssociation (IUGA) / Association (IUGA) / International International Continence Society Continence Society (ICS) (ICS) J i t R t thJ i t R t th Schaer GNSchaer GN
Neurourology and Neurourology and UrodynamicsUrodynamics2010201029 29 (pp. 4(pp. 4--20)20)
International Urogynecology International Urogynecology JournalJournal2010201021 21 (pp. 5(pp. 5--26)26)
Joint Report on the Joint Report on the Terminology for Female Terminology for Female Pelvic Floor Pelvic Floor DysfunctionDysfunction
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Hosker G Hosker G Rosier PRosier PGajewski JGajewski JSand PSand PSzabo LSzabo LCapewell ACapewell A
Chapter 6: Dynamic Chapter 6: Dynamic Testing (pp 413Testing (pp 413--522)522)
Distributor: Editions 21 Distributor: Editions 21 Paris FranceParis FranceISBN: 0ISBN: 0--95469569546956--88--2 2
www icsoffice orgwww icsoffice orgwww.icsoffice.orgwww.icsoffice.org
Topics coveredTopics covered
•• PressurePressure•• TransducersTransducers•• Different types of transducerDifferent types of transducer•• Different types of transducerDifferent types of transducer•• Issues with bladder pressureIssues with bladder pressure•• Normal cystometryNormal cystometry•• Flow measurementFlow measurement•• PressurePressure--flow testsflow tests
What is pressure?What is pressure?
Force per unit areaForce per unit areaForce per unit areaForce per unit area
►► demonstrationdemonstration
Note the level of fluid in the tube is higher than the balloon.Note the level of fluid in the tube is higher than the balloon.
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Why is level of fluid in the tube higher than the balloon?Why is level of fluid in the tube higher than the balloon?
The pressure inside the balloon is The pressure inside the balloon is transmitted up the tube and transmitted up the tube and supports a column of watersupports a column of water
What, apart from pressure, dictates the height of fluid in the tube?What, apart from pressure, dictates the height of fluid in the tube?
Diameter of tube does not matterDiameter of tube does not matter
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Pressures on holidayPressures on holiday Does the density of the fluid determine the height to which the fluid goes?Does the density of the fluid determine the height to which the fluid goes?
Density mattersDensity matters
Thus we need to state pressure Thus we need to state pressure both in terms of a height and both in terms of a height and
also in terms of a particular fluidalso in terms of a particular fluid
Unit of pressureUnit of pressure
cm Hcm H22OO
1 cm H1 cm H22O = 0.74 mm HgO = 0.74 mm Hg100 cm H100 cm H22O = 74 mm HgO = 74 mm Hg
How to measure bladder pressureHow to measure bladder pressure
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Pressure transducersPressure transducers
External pressure transducer with dome and tapsExternal pressure transducer with dome and taps
External pressure transducer without domeExternal pressure transducer without dome
External pressure transducer without domeExternal pressure transducer without dome
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Catheter-tip pressure transducersCatheter-tip pressure transducers T-DOCT-DOC
External transducer specificationsExternal transducer specifications Transducer characteristicsTransducer characteristics
Good linearity Good linearity Minimal hysteresisMinimal hysteresisMinimal hysteresisMinimal hysteresisMinimal zero shiftMinimal zero shiftMinimal sensitivity shiftMinimal sensitivity shift
CalibrationCalibration
•• Urodynamic equipment is not perfect and Urodynamic equipment is not perfect and its accuracy can alter with time. Therefore, its accuracy can alter with time. Therefore, regular checks of its calibration are essential regular checks of its calibration are essential gg
OverpressurisationOverpressurisation
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Transducer typesTransducer types
•• Catheter tipCatheter tip•• Air filledAir filledAir filledAir filled•• Fluid filledFluid filled
Catheter-tip pressure transducersCatheter-tip pressure transducers
CatheterCatheter--tip pressure transducerstip pressure transducersCatheterCatheter--mounted pressure transducersmounted pressure transducersMicrotip transducersMicrotip transducersMicrotip transducersMicrotip transducersSolid state transducersSolid state transducers
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Catheter-mounted pressure transducer’s lack of movement artefactCatheter-mounted pressure transducer’s lack of movement artefact
Catheter-mounted pressure transducersCatheter-mounted pressure transducers
No fluid connecting the patient to the No fluid connecting the patient to the equipment equipment –– only wiresonly wires
No flushingNo flushing
No need to set anything at a reference levelNo need to set anything at a reference level
T-DOCT-DOC
Air-charged cathetersAir-charged catheters
No fluid connecting the patient to the equipment No fluid connecting the patient to the equipment ––only aironly air
No flushingNo flushing
No need to set anything at a reference levelNo need to set anything at a reference level
No substantial comparisons with fluidNo substantial comparisons with fluid--filled linesfilled lines
“No fluid” pressure measurement“No fluid” pressure measurement
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Fluid-filled pressure linesFluid-filled pressure lines Issues in filling cystometryIssues in filling cystometry
Do you use external pressure transducers Do you use external pressure transducers connected to the patient via fluidconnected to the patient via fluid--filled lines filled lines or do you use catheteror do you use catheter--mounted pressure mounted pressure yy pptransducers?transducers?
External pressure transducerExternal pressure transducer Catheter-mounted pressure transducerCatheter-mounted pressure transducer
Recommendation - PressureRecommendation - Pressure
It is recommended that for intravesical and It is recommended that for intravesical and abdominal pressure recording, external abdominal pressure recording, external pressure transducers connected to fluidpressure transducers connected to fluid--ppfilled tubes and catheters should be used.filled tubes and catheters should be used.If microtip or airIf microtip or air--filled catheters are used, filled catheters are used, any deviation from standard zero and any deviation from standard zero and reference level should be minimised and reference level should be minimised and taken into account at the time of analysistaken into account at the time of analysis
atm atmstrain gauge
Measuring bladder pressure with a fluid-filled lineMeasuring bladder pressure with a fluid-filled line
patient
sterile water
amplifier
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Position of the bladder relative to the transducerPosition of the bladder relative to the transducer
Recommendation - PressureRecommendation - Pressure
We need to know the reference height of the We need to know the reference height of the transducerstransducers
Compare readings on the same patientCompare readings on the same patientCompare readings on the same patientCompare readings on the same patientCheck for realistic pressuresCheck for realistic pressuresEqual reference for pEqual reference for pabdabd, p, pvesves relative to bladderrelative to bladder
The ICS standard reference height is the The ICS standard reference height is the upper edge of the symphysis pubisupper edge of the symphysis pubis
Level with the symphysis pubisLevel with the symphysis pubis CalibrationCalibration
•• Urodynamic equipment is not perfect and Urodynamic equipment is not perfect and its accuracy can alter with time. Therefore, its accuracy can alter with time. Therefore, regular checks of its calibration are essential regular checks of its calibration are essential gg
•• 0 to 50 cmH0 to 50 cmH22O O before clinicbefore clinic
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Pump artefactPump artefact
The effect of air in the systemThe effect of air in the system
Effect of air in the systemEffect of air in the system
BladderBladderTransducerTransducer
Effect of air in the systemEffect of air in the system
BladderBladderTransducerTransducer
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Flushing a fluid-filled lineFlushing a fluid-filled line
patient
sterile water
Flushing a fluid-filled lineFlushing a fluid-filled line
Topics coveredTopics covered
•• PressurePressure•• TransducersTransducers•• Different types of transducerDifferent types of transducer•• Different types of transducerDifferent types of transducer•• Issues with bladder pressureIssues with bladder pressure•• Normal cystometryNormal cystometry•• Flow measurementFlow measurement•• PressurePressure--flow testsflow tests
What route is used for inserting pressure sensors in the bladder?What route is used for inserting pressure sensors in the bladder?
TransurethralTransurethral
SuprapubicSuprapubic
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Suitable sites for measuring abdominal pressureSuitable sites for measuring abdominal pressure
RectumRectum
Vagina (upper part)Vagina (upper part)Vagina (upper part)Vagina (upper part)
Abdominal stomaAbdominal stoma
Symbol of pressureSymbol of pressure
pppp(p not P)(p not P)
QualifiersQualifiers
det det –– detrusordetrusorves ves -- intravesicalintravesicalabdabd abdominalabdominalabd abd –– abdominalabdominalura ura –– urethralurethral
ppdetdet, p, pves, ves, ppabd, abd, ppuraura
Definition of detrusor pressureDefinition of detrusor pressure
pp = p= p ppppdetdet = p= pves ves -- ppabdabd
Why subtract?Why subtract?
ppvesves
ppvesves
ppdetdet
ppabdabd
Why not just display detrusor?Why not just display detrusor?
ppdetdet
ppvesves
ppdetdet
ppabdabd
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Rectal artefactRectal artefact Why then display all three?Why then display all three?
Quality controlQuality control
ppdetdet
ppvesves
ppabdabd
Quality controlQuality control
ppdetdet
ppvesves
ppabdabd
Quality controlQuality control
ppdetdet
ppvesves
ppabdabd
Quality controlQuality control
ppdetdet
ppvesves
ppabdabd
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Quality controlQuality control
ppdetdet
ppvesves
ppabdabd
Quality controlQuality control
ppvesves
ppabdabd
Quality controlQuality control
ppdetdet
ppvesves
ppabdabd
Quality controlQuality control
ppdetdet
ppvesves
ppabdabd
Quality controlQuality control
ppvesves
ppabdabd
Quality controlQuality control
ppdetdet
ppvesves
ppabdabd
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Biphasic spikeBiphasic spike
A BIG issue in filling cystometryA BIG issue in filling cystometry
Do you zero your transducers inside the Do you zero your transducers inside the patient, outside the patient, to atmospheric patient, outside the patient, to atmospheric pressure or to resting bladder pressure?pressure or to resting bladder pressure?p g pp g p
Zeroing to atmosphere
X
X
Zeroing while connected
X
Recommendation - PressureRecommendation - Pressure
It is recommended that there is strict It is recommended that there is strict adherence to the ICS standardisation of zero adherence to the ICS standardisation of zero pressure and reference heightpressure and reference heightp gp g
Zero pressure is the surrounding atmospheric Zero pressure is the surrounding atmospheric pressurepressure
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Pressures at beginning of filling cystometryPressures at beginning of filling cystometry
Pressures at beginning of filling cystometryPressures at beginning of filling cystometry
Reasons to zero to atmospheric pressureReasons to zero to atmospheric pressure
It produces a scientifically meaningful parameterIt produces a scientifically meaningful parameter
Has a role in quality controlHas a role in quality control
When comparing with other centre’s data, it is When comparing with other centre’s data, it is necessary to compare like with likenecessary to compare like with like
Some measurements (Some measurements (egeg VLPP) are made on the VLPP) are made on the intravesicalintravesical or abdominalor abdominal pressure not detrusor pressure not detrusor pressurepressure
Zeroing to atmosphereZeroing to atmosphere
Detrusor overactivity & fillingDetrusor overactivity & filling
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Patient positionPatient position
In only 38% of bladders displaying detrusor In only 38% of bladders displaying detrusor overactivity is the overactivity manifest on overactivity is the overactivity manifest on supine filling cystometrysupine filling cystometryp g y yp g y y
Issues in filling cystometryIssues in filling cystometry
Do you use external pressure transducers connected Do you use external pressure transducers connected to the patient via fluidto the patient via fluid--filled lines or do you use filled lines or do you use cathetercatheter--mounted pressure transducers?mounted pressure transducers?Do you zero your transducers inside the patient or Do you zero your transducers inside the patient or y y py y pto atmospheric pressure?to atmospheric pressure?What rate should you fill the patient?What rate should you fill the patient?What temperature should the filling medium be at?What temperature should the filling medium be at?What position should the patient be in?What position should the patient be in?What provocation should be used?What provocation should be used?How do you define detrusor overactivity?How do you define detrusor overactivity?
Detrusor overactivityDetrusor overactivity
Clinically significant detrusor contractions Clinically significant detrusor contractions h hi h i d i h ih hi h i d i h iare those which are associated with patient are those which are associated with patient
symptoms symptoms
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Urodynamic equipmentUrodynamic equipment
HardwareHardware
nhscep.useconnect.co.uk
Normal cystometryNormal cystometry
Free flow rate measurementFree flow rate measurement UroflowmetryUroflowmetry
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FlowmetersFlowmeters
Load cell (gravimetric)Load cell (gravimetric)Rotating discRotating discCapactive dipstickCapactive dipstickCapactive dipstickCapactive dipstickPressure sensorPressure sensorAir displacementAir displacement
Load cell flowmeterLoad cell flowmeter
Rotating disc flowmeterRotating disc flowmeter
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Free flow rate measurementFree flow rate measurement Free flow rate measurementFree flow rate measurement
Free flow rate measurementFree flow rate measurement Free flow rate measurementFree flow rate measurement
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Free flow rate measurementFree flow rate measurement
Voided volumeVoided volumePatient apprehensionPatient apprehensionPatient positionPatient position
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Free flow rate measurementFree flow rate measurement
What does it tell us?What does it tell us?
Whether there is a problem with voidingWhether there is a problem with voidingWhether there is a problem with voidingWhether there is a problem with voiding
It DOES NOT tell us whether any problem It DOES NOT tell us whether any problem is due to outflow obstruction or poor is due to outflow obstruction or poor detrusor contractilitydetrusor contractility
Normal pressure-flowNormal pressure-flow
PPdetQmaxdetQmax: 40: 40--60 cm H60 cm H22O (male)O (male)
PP : 20: 20 40 cm H40 cm H O (female)O (female)PPdetQmaxdetQmax: 20: 20--40 cm H40 cm H22O (female)O (female)
Normal pressure-flow (female)Normal pressure-flow (female)
Outflow obstruction (female)Outflow obstruction (female)
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Normal pressure-flow plotNormal pressure-flow plot Obstructed pressure-flow plotObstructed pressure-flow plot
ICS nomogramICS nomogram Pressure-flow plotsPressure-flow plots
PURRPURRLPURRLPURRURAURAURAURACHESSCHESSICS (AbramsICS (Abrams--Griffiths) nomogramGriffiths) nomogramBOOI (AbramsBOOI (Abrams--Griffiths number) Griffiths number)
BOOI (Abrams-Griffiths number)BOOI (Abrams-Griffiths number)
ppdetQdetQmaxmax -- 2Q2Qmaxmax
< 20< 20 non obstructednon obstructed> 40> 40 obstructedobstructed
Female pressure-flow nomogramFemale pressure-flow nomogram
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Topics covered - summaryTopics covered - summary
•• PressurePressure•• TransducersTransducers•• Different types of transducerDifferent types of transducer•• Different types of transducerDifferent types of transducer•• Issues with bladder pressureIssues with bladder pressure•• Normal cystometryNormal cystometry•• Flow measurementFlow measurement•• PressurePressure--flow testsflow tests
Types of flowTypes of flow
Transducer characteristicsTransducer characteristics
NonNon--linearitylinearityElectrical signal does not change inElectrical signal does not change inElectrical signal does not change in Electrical signal does not change in proportion to the pressure put on itproportion to the pressure put on it
Non-linearityNon-linearity
LinearityLinearity Transducer characteristicsTransducer characteristics
HysteresisHysteresisElectrical signal for a given pressure isElectrical signal for a given pressure isElectrical signal for a given pressure is Electrical signal for a given pressure is different when that pressure is reached from different when that pressure is reached from a lower pressure than when it is reached a lower pressure than when it is reached from higher pressurefrom higher pressure
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HysteresisHysteresis No hysteresisNo hysteresis
Transducer characteristicsTransducer characteristics
Zero shiftZero shiftElectrical signal when no pressure isElectrical signal when no pressure isElectrical signal when no pressure is Electrical signal when no pressure is applied to the transducer changes if the applied to the transducer changes if the temperature of the transducer changestemperature of the transducer changes
Zero driftZero drift
Transducer characteristicsTransducer characteristics
Sensitivity shiftSensitivity shiftElectrical signal for a given pressureElectrical signal for a given pressureElectrical signal for a given pressure Electrical signal for a given pressure changes if the temperature of the transducer changes if the temperature of the transducer changeschanges
Sensitivity driftSensitivity drift
