Urodynamics Interpretation Course

Dr. Arthur MourtzinosUrologist Lahey Clinic, Burlington, MA

Instructor Background

MD, Boston University School of Medicine

General Surgery, Mass General Hospital

Urology, Lahey Clinic Medical Center

Fellowship in male and female pelvic reconstructive surgery

and urinary incontinence, UCLA Medical Center

Expertise in treating patients with complex pelvic injuries,

pelvic floor prolapse, urinary incontinence and cancer-

related abnormalities of the pelvic floor and urinary tract

Course Outline

Urge/Stress Incontinence and Overactive Bladder

LUTS and the Central Nervous System

Introduction to Urodynamics

Uroflow

EMG

Interpretation of the Results

Pressure Flow Studies

UPP Studies

Post Procedure

Patient Study Analysis

Urge/Stress Incontinence

& Overactive Bladder

Patient Assessment

Pelvic Examination

History

H&P

Cystoscopy

Urodynamic Testing

Mechanisms of Continence

All 3 must be present for continence

1. Anatomic integrity of urinary tract

2. Appropriate/intact nervous system

3. Sphincter competence (ex: estrogen)

Stress Incontinence: VLPPRest & Straining

Urinary Urge Incontinence

Involuntary leakage accompanied by or immediately

preceded by urgency

Detrusor pressure exceeds urethral pressure

Leakage day and night

Storage / Filling

Detrusor relaxation and urethral contraction

Low detrusor pressure and high urethral pressure

Voiding / Emptying

Detrusor contraction and urethral relaxation

High detrusor pressure and low urethral pressure

LUTS and the

Central Nervous System

Neuro-bladder pathways

Bladder always in the

wanna go mode

Introduction to Urodynamics

Urodynamics

A series of diagnostic studies used to evaluate a patients ability to store and eliminate urine

The goal is to reproduce bladder filling/storage and voiding/emptying symptoms to identify underlying causes

Indications for Urodynamics

Mixed urinary incontinence prior to surgery

Iritative voiding symptoms unresponsive to conservative therapy or with associated co-morbidities

Incontinence post trauma or pelvic surgery

Failed anti-incontinence surgery

Recurrent UTIs

Spinal Cord Injury, history of neurologic disorders

Children with neurologic disorders, nocturnal enuresis, or recurrent UTIs

Pressure Measurements

Intra-vesical pressure (Pves)

Abdominal pressure (Pabd)

Detrusor pressure (Pdet)

Electromyography (EMG)

Uroflowmetry (Qura)

Urethral Pressure (Pura)

Urethral Closure Pressure (Pclos)

Intravesical Pressure (Pves)

Combination of abdominal and detrusor forces acting upon the bladder (cmH20).

Intra-abdominal Pressure (Pabd)

The abdominal forces acting upon pelvic and abdominal contents. Measured using a rectal or vaginal catheter (cmH20).

Detrusor Pressure (Pdet)

The true pressure of the detrusor contraction derived from subtraction of Pabd from Pves. It is created by forces in the bladder wall (passive or active) (cmH20).

Uroflowmetry (Qura)

Screening test measuring vol of urine (ml) expelled from the bladder in unit of time (ml/sec).

Electromyography (EMG)

Evaluation of striated sphincter during filling and voiding (uV amplitude).

Urethral Pressure (Pura)

Fluid pressure needed to just open a closed urethra (cmH20).

VCUG

Radiographic visualization of the lower urinary tract during filling and voiding.

Pressure Relationships

Uroflow

Uroflow

Measured in cc/second

Observe flow pattern

Review voiding diary for volume voided

Minimum voided volume needed (150-200cc)

Max flow rate (Qmax)

Men >12cc/sec

Women >20cc/sec

Ave flow rate (Qave) should be 50% of Qmax

Specific to age and gender

Post Void Residual

PVR 50ml -100ml = low end of abnormal PVR range

Large PVR 100-300ml will increase risk of UTI and serious complications

PVR>300ml can cause upper tract dilitation and renal insufficiency

High PVR Causes: BOO, DSD, Bladder Hypo/Hypercontractility

Uroflow Parameters

Normal Flow

Low Flow

Intermittent Flow

Electromyography (EMG)

The Electromyogram (EMG)

Detects pelvic floor muscle activity

Recorded during the filling, cystometry and pressure

flow studies

During a voluntary voiding event the striated muscle of

the external urinary sphincter relaxes as the detrusor

muscle contracts

Filling and voiding (EMG)

During filling, a slight increase in the amplitude of the

EMG may be seen (guarding or continence reflex)

with the urge to void

During voiding this activity should become silent as

the bladder contracts for a synergic voiding event

Interpretation of the Results

Interpretation of Results 3Cs and 2Ss

Capacity

Compliance

Competence

Sensations

Stability

Capacity

Amount of fluid the bladder holds

Slow fill (10cc/min)

Medium fill (10-100cc/min)

Fast fill (over 100cc/min)

Adults: 300ml-600ml (diminishes with age)

Children: (age in years + 2) x 30 = cap in ml

Compliance

The relationship between change in bladder volume

and change in detrusor pressure

It is expressed as ml/cmH20

Detrusor pressure 40 cmH20 may lead to upper

urinary tract dysfunction

Bladder Compliance

Bladder Compliance

Detrusor Over Activity

Atonic Bladder

Competence (of the Sphincter)

Ability of the external striated muscle to hold urine and

relax and release urine

Evaluated using Valsalva Leak Point Pressure (VLPP)

and/or Urethral Pressure Measurement

Sensations

Sensations of patient affected by volume, pressures and

psychosocial environment

First sensation of bladder filling: 60-150ml

becomes aware of the bladder filling

First desire to void: up to 200ml

would void next convenient time, but could hold

Strong desire to void: 400-600ml

persistent desire to void without fear of leak

Stability (Detrusor function)

Normal detrusor function - allows bladder filling with little or no change in pressure. No involuntary phasic contractions occur despite provocation.

Detrusor Overactivity - a urodynamic observation characterized by involuntary detrusor contractions during the filling phase which may be spontaneous or provoked.

Pressure-flow Studies

Voiding/Emptying

Pressure Flow - measuring detrusor pressure during urinary flow

Flow rate: >12ml/sec males and >20ml/sec females

Detrusor pressure:

High Pressure Low Flow

What kind of prs/flow is this?

Diagnosis

Bladder Outlet Obstruction

Obstructive voiding pattern

High detrusor pressure

Low urine flow rate

Whats happening in this study?

Diagnosis

The PVES catheter fell out at peak pressure during the

voiding phase

Whats happening in this study?

Answer

Detrusor Overactivity

Whats happening in this study?

Answer

Normal Study

Urethral Pressure Profile

Studies (UPP)

Pressure Transmission Ratio = the increment in urethral pressure on stress as a percentage of the simultaneously reported increment in the vesical pressure. [cough or dynamic UPPs]

Urinary continence depends on the pressure in the urethra exceeding the pressure in the bladder at all times, even with increases in abdominal pressure.

60 90 Normal Closure Pressure

20 60 Intrinsic Sphincter Deficiency

Less than 20 Incompetent Urethra

UPPs

UPP Diagram

Urethral catheter being withdrawn

Pressure tracing

Urethral Pressure Profile Measurements

Normal UPP

Post Procedure Instructions

Drink six 12 oz. glasses of

water today

Small amount blood

May have

frequency/urgency for

24-48 hours acmi

Call for temp 101.5

Call if unable to void

after 6 hours

Return appointment

+/- Antibiotics

Written instructions

Thank you for your attention !