URODINAMYCS: a prime for the beginner

by GIANCARLO VIGNOLI, MDUrodynamics and Urogynecological Unit

Casa “Madre Fortunata Toniolo”Bologna

Foreword

Urodynamics describes a group of physiological tests that are used in clinical practice to investigate abnormalities of lower urinary tract function. Contrary to popular belief, it is not an esoteric subject of limited applicability or difficult science. In fact, the principles underlying urodynamics are simple, and the techniques

entirely logical in their application

Summary

• Micturition cycle• History & Physical “ urodynamically – oriented”

• Non-invasive urodynamics

• Invasive urodinamics

• Videourodynamics

• Ambulatory urodynamics

• Diagnostic software

Sources :

• Blaivas J, Lower Urinary Tract Physiology and Pathophysiology,FUUS 2008

• Blaivas J ,Evaluation of Lower Uirnary Tract Dysfunction, FUUS 2009

• Hosker G , Good Urodynamic Practice,ICS 2008

• Kastgir J et a.Course on Urodynamics ,TTmed Urology,2010

• Life-Tech Introduction to Urodynamics

• Yasuhiko Igawa,Neurogenic Bladder, ICS 2007

• Khalafalla AH,Urethral Pressure Profile (web slides)

Micturition cycle: filling

• As the bladder fills progressively, relaxation of the bladder (detrusor) muscle allows low pressure storage of urine, aided by inhibitory mechanisms within the spinal cord and pelvic ganglia. Concurrently, the complex system of sphincters that encircle the urethra start to contract in keeping with bladder filling in order to increase urethral resistance and maintain continence.

Micturition cycle: voiding

• Conversely, voiding is a voluntary act that is associated with a lowering of urethral resistance by sphincter relaxation followed by a coordinated contraction of the detrusor muscle which leads to complete emptying of the stored urine.

Related events

• Voluntary interruption of voiding

• Cough

• Strain ( Valsalva)

• This combination of physiological and mechanical functions may be altered by various processes, and manifests in various ways, such as incontinence, detrusor muscle overactivity, voiding dysfunction, and so on.

• Urodynamics in its purest sense is the study of the relationship between bladder pressure, volume and flow at the various stages of the micturition cycle.

No–instruments urodynamics

• It is important for the clinician to have a rudimentary understanding of the physiological processes involved and to endeavor to make a urodynamic diagnosis from the start, which is then confirmed or refuted by subsequent tests

• By employing good basic clinical skills of detailed history-taking, physical examination and a selection of simple investigations, most problems may be diagnosed in the outpatients or office setting with a rather basic understanding of lower urinary tract physiology.

Patient clinical assessment

• History including symptom score•          Physical examination which includes:•                    - Digital rectal examination (DRE) for men•                    - Pelvic examination for women•                    - Focused neurological examination•          Frequency volume chart/voiding diary•          Urine dipstick analysis•          Urine microscopy and culture•          Post-void residual volume (bladder scan)•          Pad test•          Q-tip test•  

Patient Sheet Front Page

• Patient : Ref :

• Age :

• Main symptom : *• Degree of bother:*• Comorbidities:• Drugs:• Previous surgery :

Questionnaires *

• Incontinence Impact Questionnaire (IIQ)

• Urogenital Distress Inventory (UDI)

• International Prostate Symptom Score (IPSS)

Types of Bladder Diary

• Micturition time chart

• Frequency -volume chart • Complete Bladder diary ( including fluids,degree of

urgency ,etc.)

Electronic Bladder Diary

Informations derived from Bladder Diary

It provides an objective record of symptoms (frequency, leakage episodes) and their severity

Maximum and average voided volumes, the “functional bladder capacity”

Distinguishes frequency from global polyuria (> 2.8 L urine output in 24 h)

Distinguishes between nocturia and nocturnal polyuria (nocturnal polyuria is > 30% of total 24-hour output occurring at night; it may reflect the presence of extraurinary tract pathology such as congestive cardiac failure, and abnormalities of antidiuretic or atrial natriuretic hormone secretion)

1-hour Pad Test ( positive > 5 gr)

ICS RECOMMENDATIONS:

• 1. Patient voids• 2. Pre-weighed collecting device is put on

and 1-h test begins• 3. 0-15 min: subject drinks 500 mL of

sodium-free liquid and sits/rests• 4. 15-45 min: subject walks and climbs

equivalent of one flight up and down stairs• 5. 45-60 min: subject performs following

activities:     - standing up from sitting 10 times    - coughing vigorously 10 times    - running on the spot for 1 min    - bending to pick up small objects off the floor five times    - washing hands in running water for 1 minute

• 6. At the end of the 1-h test the collecting pad is removed and reweighed

• 7. If the test is thought to be representative, the subject voids and the volume is recorded

Vaginal Examination ( Inspection )

Vaginal Examination ( Stress Test )

Q-TIP TEST

POP-Q Instruments

POP-Q iuga simplified version

• gh 3 cm• pb 2 cm

• Tvl 10 cm• Ap 3 cm• Bp 3 cm

Source :Swift S , 2006

POP-Q ( gh : 3 cm )

POP-Q ( D : 10 cm )

POP-Q ( Aa : 3 cm )

POP-Q ( Ap : 3cm )

BARD Interactive Guide

Focused Neurological Examination

• Perianal sensation• Anal reflex (scratching the

perineum makes the anus “wink”)

• Anal sphincter tone & Voluntary control

Non-invasive urodynamics

Flowmetry

Uroflowmetry is a simple, noninvasive technique which is easily performed in the outpatient setting and is often used as a screening test for voiding problems, or a means of selecting patients who require more complex urodynamic studies

Flow Recorders

• Weight • Rotating Disc

Commode

Flow Curve Analysis

Qmax : Normal Ranges

Males under 40 years: > 21 mL/sec                       Females under 50 years: > 25mL/sec         Males 40-60 years: > 18 mL/sec                           Females over 50 years: > 18 mL/secMales over 60 years: > 13 mL/sec

Male Free Flowmetry Predictive Value

• Qmax < 10 mL/sec:     90% have bladder outflow obstruction• Qmax 10–14 mL/sec:   67% have bladder outflow obstruction• Qmax > 15 mL/sec:     30% have bladder outflow obstruction

Flow Nomograms

Siroky ( male < 50) Bristol ( male > 50)

Liverpool ( women )

Pediatric Flow Nomograms( < 14 y.o.)

Post-Voiding Residual (Ultrasounds & Bladder Scan)

Post- Voiding Residual : Normal Ranges

Poorly defined

50 ml lower threshold

50-100ml equivocal

>100ml abnormal

>300ml check upper tract

Clinical Samples

Normal Tracing

Bladder Outflow Obstruction

Urethral stricture

Abdominal straining or Detrusor – Sphincter dyssinergia

Common artefacts

Moving back and forth Squeezing glans

Invasive Urodynamics

Cystometry & Pressure/Flow study

Clinical Preparation• The only absolute contraindication to

urodynamics is a clinical urinary tract infection !

• The best way to determine the presence of infection is to simply do a dipstick on the patient’s urine when they arrive and perform a uroflow

• Patient’s with positive dips (nitrite) should be rescheduled and treated after catheterized urine is sent for analysis.  

• There are no urodynamic emergencies!• When unsure of the safety of the situation,

always consider rescheduling.

Source : Life-Tech Introduction to Urodynamics

Life-Tech Urolab

Examination Chair

Patient's position (including children patients) can be gradually

adjusted from lying to sitting position 

Set-up

Catheters

bladder ( filling & recording) rectum

Air-charged catheter ( Laborie Medical Technologies)

• Micro-air charged balloon circumferentially placed around the catheter

• Eliminate directional artifactual sensing

• Particularly suitable for urethral pressure measurement

• Relatively inexpensive

External strain gauges

Subtraction Cystometry pdet = pves-pabd

Calibration : pdet < 6 cm H20

Common artefacts

Negative rectal pressure simulates a detrusor contraction

EMG

Types of EMG

Two types of information can be obtained from EMG:

a) a simple indication of muscle behavior (the kinesiological EMG) - the usual EMG in urodynamics

b) an electrical correlate of muscle pathology

( the neurophysiological EMG)

Patch (surface) EMG electrodes for females and males

The kinesiological EMG 

Source : Life-Tech Introduction to Urodynamics

Placement of wire electrodes in female

The neurophysiological EMG

Source : Life-Tech Introduction to Urodynamics

Placement of wire electrodes in male

The neurophysiological EMG

Source:Life-Tech Introduction to Urodynamics

EMG-Interpretation

• Synergic activity

• Dyssinergic or Non-relaxing activity

• Low amplitude activity*

* check neurophysiological study

Types of Dyssinergic activity

The procedure in 10 steps

1. Check transducers reference height: this is defined at the upper edge of the symphysis pubis, and is the level at which all external transducers must be placed for all the urodynamic pressures to have the same hydrostatic component.

2. Check patency of fluid lines by flushing

3. Check quality control of pressure signals: the resting values for the readings should be in a typical range and adequate subtraction should be evaluated by asking the patient to cough (there should be no more than a minor deflection, if at all, on pdet) .

4. Suggested filling rate : 50ml/min5. During filling there should be continuous conversation between the examiner and the patient and

every endeavor should be made to reproduce the symptoms. The patient should be instructed to tell the examiner when they first develop a sensation of bladder filling and when they have normal and strong sensations to void, as well as sensations of urgency and pain. 

6. Coughs should be repeated regularly throughout the fill to check urodynamic stress incontinence7 . At 200 ml of filling , patient is asked to cough and strain and VLPP is evaluated .8 . Once the bladder is full, filling is stopped and the patient is asked to void into an uroflowmeter with

the catheters in situ. This allows pressure-flow readings to be taken concurrently and examines the voiding phase. 

9 . After voiding the patient should again be asked to cough to test that the catheters have not moved during micturition . 

10. Failure to show equal pressure transmission after voiding would suggest that the voiding trace cannot be accurately interpreted.

Interpretation of traces

Assessment of Compliance

• Bladder compliance describes the relationship between bladder volume and bladder pressure (dv /dp) and is expressed as increase in bladder volume per centimeter of water increase in bladder pressure (ml/cmH20)

• In the normal bladder with a capacity of 400ml the change in pressure form empty to full should be less than 10 cm H20, giving a figure for normal compliance of 40 ml/cmH20

• Values greater than 10 cmH20 or lower than 40ml/cmH20 at bladder capacity indicate a reduced compliance

Clinical Samples

Urgency

Urodynamic Spectrum

Phasic contractions - Good sphincter controlOAB - dry

Phasic contractions - Poor sphincter controlOAB - wet

Terminal contractions - Poor brain control

Sensory Urgency

Stress Urinary Incontinence

• The role of urodynamics in stress urinary incontinence is a subject

of ongoing debate. • NICE Guidelines does not recommend the routine use of

preoperative urodynamics for women suffering with stress urinary

incontinence • However,only 50% of women who report pure stress incontinence

have pure urodynamic stress incontinence • There is some evidence that low urethral closure pressures may be

associated with poorer outcomes. • There is some evidence that low amplitude DO have better

outcomes after repair,while high amplitude DO do worse

• Occult SUI is associated to POP in 15-30% of the patients.    

Urodynamic stress incontinence

the involuntary leakage of urine during increased abdominal pressure, in the absence of a detrusor contraction.

observed leakage

observed leakage

Urethral hypermobility

ISD

Valsalva leak point pressure

Leak Point Pressure Leak point information is obtained either by having the patient cough or

valsalva.

The method that provides good leak pressure information utilizes Valsalva instead of cough.

Bladder filled at 200 ml

Analysis

VLPP < 60cm H20 ISD

VLPP 60 to 90 cmH20 Equivocal

VLPP > 90 cm H20 Hypermobility

Source : Life-Tech Urodynamics

Mixed urinary incontinence

cough uncontrolled voiding reflex

Female obstruction

• There is a distinct lack of consensus relating to the use of urodynamic assessment in the interpretation of voiding dysfunction in women.

• There are universally accepted nomograms for men with outflow obstruction but there remain various different urodynamic criteria for women.

• Recent attempts have been made to simplify and clarify these, such as the nomogram proposed by Blaivas and Groutz in 2000, but standardization is still awaited.

BLAIVAS-GROUTZ NOMOGRAM

Male bladder outlet obstruction

Common artefacts

Loss of bladder line during voiding

The main urodynamic findings in men with LUTS include:

- Bladder outflow obstruction ( usually secondary to benign prostatic obstruction)

- Detrusor overactivity ( primary or secondary to obstruction)

- Dysfunctional voiding

- Detrusor underactivity ( primary or secondary to dysfunctional voiding)

PRESSURE/ FLOW ANALYSIS ICS Nomograms

BOO Index: pdetMax-2Qmax 20-40 equivocal <20 unobstructed >40 obstructed

BC Index: pdetMax+5Qmax 150 strong 100-150 normal activity <100 weak

Abrams P, 1999

Bladder outlet obstruction

The ICS has defined Dysfunctional voiding as an intermittent and / or fluctuating flow rate due to involuntary intermittent contractions of peri-urethral striated muscle during voiding in neurologically normal patients

Dysfunctional voiding

Non-invasive BOO analysis

Non-invasive BOO analysis

• Penile cuff test:

pressure interrupting flow is close to true isovolumetric pressure measured by conventional urodynamics

Penile cuff test nomogram

Pediatric dysfunctional voiding

Pseudodyssinergia in a boy with recurrent UTI

Neurogenic Bladder

Source:YASUHIKO IGAWA, ICS 2007

Special Clinical Scenario: Spinal Cord Injury

It is IMPERATIVE that clinicians performing studies on quadriplegics with a cervical spine injury at C-6 or above be

prepared to recognize and treat Autonomic Dysreflexia.

Symptoms of Autonomic Dysreflexia

• Rapid, increase in B/P of 20-40 mmHg or greater• Pounding headache• Heavy sweating (usually above the level of the SCI)• Goose bumps (usually above the level of the SCI)• Stuffy nose• Tightness in the chest• Palpitations• Dyspnea• Anxiety• Jitters• Blurred or spotty vision

When doing urodynamics on a patient with potential risk for autonomic dysreflexia:

1. Monitor B/P and pulse continuously throug the procedure.

2 . Instill 2% xylocaine before catheterization.

3. Use body temperature fluids to fill the bladder.

• 4. Be prepared to:– Empty the bladder immediately if B/P elevating or episode

imminent.– Raise the patient’s head if not already sitting.– Reduce sustained systolic B/P greater than 150mmHg

pharmacologically with rapid acting antihypertensive agents, such as Nifedipine, immediate release – “bite and swallow”

• 5. Reverse symptomatic hypotension caused by sudden bladder decompression or meds. To do this:– Lower head and raise legs.– Administer IV fluids and anit-hypotensives.

6. Monitor the patients at least 2 hours after resolution of the episode.7. Admit the patient to the hospital if there is poor response to treatment.8. Document the episode according to recommended guidelines

Source : Life-Tech Introduction to Urodynamics

Videourodynamics

Videourodynamics ( VUDS ) adds a structural element to

the functional study of standard urodynamics by enabling real-time visualization of the relevant anatomy with simultaneous pressure recordings, which makes it the most comprehensive urodynamic assessment possible.

VUDS is indicated when simultaneous anatomical information is required in addition to the functional data

that a conventional urodynamic study provides.

Videourodynamics set-up

• Radiolucent toilet seat • Semilateral or oblique position

Neurogenic Bladder – Type 2 dyssinergia

Neurogenic bladder – Types 3 dyssinergia

4th degree reflux on the left

URETHRAL PROFILOMETRY

• UPP is the recording of intraluminal pressure along the lenght of urethra

• The study is performed during slow retraction ( 1 mm/s ) of a catheter with side holes

• Bladder pressure should be measured simultaneously to exclude effects of an associated detrusor contraction

Set-Up

2- or 3-ways catheters

Types of Profilometry

• Static urethral pressure profile ( at rest )• Dynamic urethral pressure profile ( during cough )• Micturational urethral pressure profile ( during voiding ).Rarely used

Step-by-step procedure

• Patient in supine ( sometime standing ) position• After voiding the catheter is inserted into the bladder• The residual urine is drained and recorded• The catheter is conncted to the recording equipment and to an

infusion pump.The manometer is zeroed to the air at the level of the upper edge of the symphisis

• Start infusion pump (2ml/min of saline at 37°) and recorder• Start retraction of catheter ( 1 mm/s )

Urethral closure pressure (ucp)

• The effective pressure maintaining continence is not the urethral pressure,but the so-called closure pressure ( the urethral pressure minus vesical pressure )

• If the intravesical pressure ever exceeds the urethral pressure the possibility of leakage obviously exist

MUCP Normal Values

Male :70-120 cmH20

Abrams P , Urodynamics , 3° edition ,2006,p 104.

Female: The maximum urethral pressure

increase from infancy to the age of 25 years.

90 cm H20 Thereafter, the values

decrease with increasing age

10 cm H20 by decade

Rud T ,Acta Obstet Gynecol Scand ,1980

The stress urethral profile

• The concept of the “ stress” profile was introduced by Asmussen and Ulmsten in 1976

• If the closure pressure become negative on coughing then leakage is likely to occur.

• Closure pressure may be derived electronically by subtracting intravesical pressure from intraurethral pressure and this may be displayed on chart recorder

• Pressure transmission lower than 90% in the proximal one-third of the urethra indicates a defect in urethral support

Ambulatory urodynamics

• Ambulatory urodynamic monitoring (AUM) refers to functional tests of the lower urinary tract predominantly utilizing natural filling of the urinary tract and reproducing the subject’s normal activity. 

•  Ambulatory studies seek to improve the correlation between urinary symptoms and clinical findings. 

• The indications for ambulatory urodynamic monitoring have been outlined in an ICS subcommittee report :- Lower urinary tract symptoms that conventional urodynamic fails to reproduce or explain - Situations in which conventional urodynamics may be unsuitable- Neurogenic lower urinary tract dysfunction - Evaluation of therapies for lower urinary tract dysfunction

Clinical sample : OAB Dry

Clinical sample : OAB Wet

The diagnostic software

• The software is designed to develop a better understanding of urodynamics tracings

• It does’nt make a “diagnosis”,something only a physician can do

• It merely emphasizes a ”urodynamic diagnosis“according to current resources on urodynamic testing interpretation