A guide to indications, components and interpretation of urodynamic investigations TOG 2019 Flashcards
3 main components of urodynamics
representative uroflowmetry with post-void residual (PVR)
transurethral cystometry
pressure-flow study.
According to NICE when is urodynamic testing required?
Urge, mixed urge predominant: After failure of Cx measure, before considering surgery
Stress: Only if voiding dysfunction, anterior compartment prolapse or previous surgical management
Neurological: Video urodynamics for substantial risk renal complication (SB, spinal cord injury), before surgery
Children: no guidance
When test should be performed prior to urodynamic testing
Urine dip for infection/haematruia
Urodynamic testing postposed until UTI treated.
How is uroflowmerty measured?
Void by relaxing not straining onto commode with flowmeter. Volume of urine passed per unit ofttimes ml/s and volume passed.
Post-void residual by USS or catheter
What does diagram of normal uroflowmetry look like?
Bell curve of normal flow with voided volume 250mls.
Q max 20-36mls
What are the 3 main categories of voiding dysfunction?
a) Detrusor contractility dysfunction
b) urethral dysfunction
c) bladder outflow resistance
A Uroflow like this, can indicated what?
A Uroflow like this, can indicated what?
A Uroflow like this, can indicated what?
Causes of high PVR
Anticholinergics (Detrusor under activity)
Detrusor failure
Outlet obstruction
What is cystometry?
Test to assess bladder’s storage ability
Artificially and continuously filling the bladder with fluid via Cather to measure the pressure within the bladder/intravesicle
Rectal catheter used to measure abdominal pressure
Detrusor pressure - abdo pressure - intravesicle pressure
Normal values for intravesicle and intra abdominal pressure
5-50cm H2O
Normal values for intravesicle pressure
-5-15H2O
Normal cystogram with filling and voiding phase. Not Cg - patient cough, FSF first sensation to void, SD strong desire to void
No change in Pet throughout filling despite provocation (cough)
Cystogram showing detrusor overactivity
Unprovoked rises in detrusor pressure associated with sensations of urgency.
What findings on cystogram, if low or poor detrusor compliance e.g. post radiotherapy
Steep rise in detrusor pressure during filling that persists after filling is stopped. Usually <30 ml/cm H2O. Associated with reduced bladder capacity
What findings on cystogram, if high detrusor compliance e.g. neurological causes
Generally, compliance will be >100 ml/cm H2O and can have capacities of > 1 L.
What findings on cystogram, if Poor detrusor accommodation
Rise in detrusor pressure during filling, but the pressure falls to normal when filling is stopped.
What findings on cystogram, if detrusor overactivity
Phasic – waves of detrusor contractions that may or may not be associated with incontinence
Terminal – single involuntary detrusor contraction at cystometric capacity resulting in incontinence, usually bladder emptying
Cough-associated DO – onset of DO is immediately following cough pressure peak
What findings on cystogram for urodynamic stress incontience
Urinary leakage during filling, in presence of raised abdominal pressure but in absence of detrusor contraction
If urodynamics have not answered you questions, what other tests could be considered?
pad test
videocystometry (NICE recommended6)
ambulatory urodynamics (NICE recommended6)
urethral pressure profile tests.
