Neuropathic bladder/urinary incontinence Flashcards
why are women more likely to have incontinence than men?
they have a weak bladder neck mechanism
bladder does not contract very strongly
the urethral sphincter is supported by pelvic floor muscles which are not very strong
why are men more likely to have obstructive causes of LUTS than women?
there is both a bladder neck sphincter and a distal urethral sphincter
bladder can contract quite strongly and develop high pressures
urethra is much longer
the distal urethral sphincter is also supported by the pelvic floor
it is the bladder neck mechanism that contributes a lot to obstruction and retention
why is there a bladder neck mechanism in males?
to prevent retrograde ejaculation
where does the ejaculatory duct joint the urethra?
prostatic urethra
is the bladder neck mechanism in males a urinary sphincter?
no it is a gential sphincter to prevent retrograde ejaculation
what does the cortex do in micturition?
senses whether the bladder is full
allows voluntary initiation of voiding
what does the PMC/PAG allow you to do?
co-ordination of bladder contraction and sphincter relaxation
what are the spinal reflexes of micturition?
- reflex bladder contraction when the bladder is full (but overridden by higher centres) - contrplled by the sacral micturition centre
- guarding reflex - controlled by Onuf’s nucleus
- sympathetic - receptive relaxation
from what spinal levels are the sympathetic fibres to the bladder?
T10-L2
what does the sympathetic NS do in micturition?
inhibits detrusor contraction - ie bladder relaxation
SMOOTH muscle sphincter contraction
what does the parasympathetic NS do in micturition?
detrusor contraction
SMOOTH muscle sphincter relaxation
what does the somatic pudendal nerve do?
contraction and relaxation of the STRIATED muscle sphincter - you don’t usually use this, but only when you are desperate and trying not to go
what are the storage symptoms of LUTS?
frequency
nocturia
incontinence
urgency
what are the voiding symptoms of LUTS?
slow stream splitting or spraying hesitancy straining terminal dribble intermittency
what are the post micturition symptoms?
post micturition dribble
feeling of incomplete emptying
what is the definition of frequency?
passing water more often
what is the definition of urgency?
a sudden, compelling desire to void which is difficult to defer
nocturia definition?
going to the toilet 2 or more times per night - nocturia is going to the toilet in the middle of the night with the intention of going back to sleep
incontinence definition?
involuntary loss of urine
intermittency definition?
urinating in a stop-start fashion
Hesitancy defintion?
delay in initiation of micturition
What parameters can you get from a bladder diary?
- 24 hour urine volume
- volume produced /day
- volume produced/night - if you know what time they went to sleep and woke up
- frequency of urination/day
- frequency of urination/night
- frequency of incontinence
- frequency of nocturia
- nocturnal volume ÷ 24 hour volume
- functional capacity - the maximum value in the bladder diary that the bladder has held
what is the normal urinary frequency per day?
2-8
what is the normal urinary frequency at night?
0-1
what is the normal volume per day produced for a 70kg male?
2L, should be less than 2.7 L
what is the normal volume of urine produced per night?
900mL
what is the normal nocturnal volume ÷ 24 hour volume?
1/3 = 33%
what is the functional capacity of the bladder?
> 400ml
what os the normal incontinence/day?
0
what is urgency/urge incontinence?
incontinence associated with an urgent desire to void which is difficult to defer, usually the result of overactivity of the detrusor muscles
what is stress incontinence?
occurs when there is an increase in intra-abdominal pressure eg after a cough or sneeze with weak pelvic floor muscles
what is mixed incontinence?
a combination of both stress and urge incontinence
what is continuous incontinence?
due to a fistula, eg communication between the badder and the vagina, just keep leaking urine from the vagina
what is overflow incontinence?
occurs in the presence of a FULL bladder
what is social incontinence?
occurs in those with dementia
How is overactive bladder defined?
urgency with frequency, with or without nocturia, when appearing in the absence of local pathology
How is detrusor overactivity diagnosed?
urodynamics
How is an overactive bladder managed?
behavioural therapy antimuscarinic drugs B3 agonists botox sacral neuromodulation surgery
what behavioural therapy is offered to those with overactive bladder?
- cut out alcohol and caffeine from diet
- going to the toilet less often to train the bladder to hold more urine = bladder drill
- fluid volume chart helps with this
how do anti-muscarinic agents work?
competitive inhibitors of Ach
this blpocks the parasympathetic NS and causes the detrusor muscle to relax, increasing bladder capacity
the reduces urinary frequency, urgency and urge incontinence in those with OAB
they tend to be specific for the M3 receptor, which is present in the bladder
Give examples of anti-muscarinic agents for OAB
oxybutynin
tolterodine
solifenacin
they are used as first line pharmacological treatment when bladder training is ineffective
Give an example of a beta 3 agonist and explain how it works for OAB
mirabegron
beta-3 adrenergic receptor agonist that causes relaxation of the detrusor smooth muscle of the urinary bladder and increases bladder capacity, by increasing sympathetic activity.
Hoe does botox work for OA?
it is a neurotoxin and blocks the neuromuscular junction for Ach release, so the bladder relaxes
what is a common side effect of anti-muscarinic agents?
dry mouth (remember secretions are parasympathetic and this drugs are anticholinergics)
what is a side effect of botox?
paralysis of the bladder requiring catheterisation due to incomplete bladder emptying
what is sacral modulation?
insertion of an electrode into the S3 nerve root to modulate afferent signals from the bladder to the brain, as these are the signals that cause urgency
what is the surgical option for OAB?
augmentation cystoplasty
what are the causes of stress incontinence in females?
• secondary to birth trauma - causes denervation of the pelvic floor and urethral sphincter
weakening of fascial support of bladder and urethra
• neurogenic
• congenital
How is stress urinary incontinence managed in women?
pelvic floor physio
mainstay is surgery: sling, colposuspension, bulking agents, artificial sphincter
(duloxetine is an SSRI that strengthens the female sphincter)
what are the causes stress incontinence in males?
neurogenic
iatrogenic eg radical prostatectomy
How is stress incontinence in males treated?
artificial sphincter or male sling
What are the different causes of urinary obstruction that cause voiding problems?
BPE -men
urethral stricture
prolapse/mass - mainly in women
what is the treatment of voiding symptoms that are not caused by obstruction?
it is likely they have detrusor underactivity
so use long-term catheter to empty their bladder
or sacral neuromodulation
what is the management of men with BPO with no ED?
1st line: alpha antagonist
2nd: 5 alpha reductase inhibitor
specialist: TURP
what is the management of men with BPO and ED?
1st: PDE5 inhibitor
2nd: alpha agonist
specialist: TURP/ intracavernosal injections/ penile implant
What are the treatments from 1st to specialist for men with OAB?
1st: antimuscarinic
2nd: b3 agonist/alpha antagonist
specialist: botox
what are the treatments for mixed stress and urge incontinence in men?
1st antimuscarinic
2nd: B3 agonist
specialist: TURP/botox
what are the treatments for women with OAB?
1st: antimuscarinic
2nd: B3 agonist
specialist: botox
What are the treatments for women who have stress urinary incontinence?
1st: physiotherapy
specialist: surgery
What is an unsafe bladder?
one that puts the kidneys at risk of damage
what are the risk factors for an unsafe bladder?
raised bladder pressure
vesico-ureteric reflux
chronic infection due to residual urine and stones
What are the causes of raised bladder pressure?
prolonged detrusor contraction
loss of bladder compliance (eg loss of receptive relaxation due to loss of symp NS)
