Flashcards in Geriatrics - Continence Deck (47):
In which group of patients is urinary incontinence most common?
Urinary incontinence is extremely common. It affects 1 in 30 people!
Women are more affected than men, with 2 out of 5 women over the age of 60 having continence problems. A general rule is that urinary incontinence in men is less than half that of women.
How does the prevalence of urinary incontinence change with age?
Generally, urinary incontinence increases with age. Trends within prevalence data show that the median level of prevalence shows an:
- increase in young adult life
- a plateau in middle age
- a steady increase in later life
How does the prevalence of urinary incontinence vary between acute hospital beds, HCE beds, RHs and NHs?
Urinary incontinence (+/- faecal incontinence) affects just under 1/3 of patients in acute hospital beds. This figure is roughly the same for residential homes. Nursing homes and HCE beds have higher and roughly equal prevalences of urinary incontinence.
The presence of faecal incontinence is roughly the same regardless of the location.
The presence of catheters is roughly the same on HCE as acute medical beds despite the prevalence of urinary incontinence being much higher in older patients. This is probably due to the fact that catheterisation is required in the acute setting to monitor urine output, and the fact that Geriatricians are keen to avoid catheters if possible.
What is a useful approach to asking a patient about incontinence?
Many older people do not want to discuss the issue of incontinence or feel embarrassed by it. A sensitive approach is therefore very helpful.
This could simply be asking "Do you have any problems with your bladder or bowels?" or "Do you pass urine or faeces involuntarily?"
What are lower urinary tract symptoms?
LUTS is the name given to symptoms associated with bladder and urethral problems that the International Continence Society has standardised.
What is urgency?
This is a sudden, compelling desire to pass urine.
This is an involuntary delay or inability to initiate the urinary stream.
...the need to pass urine during the night which awakens one from sleep.
Urinary incontinence is
...the involuntary loss of urine.
The bladder contracts spontaneously during filling as the patient attempts to prevent micturition. This is...
Nocturnal polyuria is...
...passing > 1/3 of your urine volume during the night.
What is urge incontinence?
This is involuntary leakage of urine accompanied or preceded by urgency.
Define overactive bladder?
This is a syndrome including urinary urgency +/- urge incontinence.
Stress incontinence is...
...the involuntary leakage of urine caused by failure of the bladder outlet to remain closed when intra-abdominal pressure rises.
What is the pathophysiology of incontinence?
Incontinence can result from:
1) weakness of the urinary outlet (stress incontinence)
2) failure of the bladder to store urine because of high bladder pressure (urge incontinence)
3) a combination of 1 and 2
4) a bladder that is overfull and overflows (bladder outlet obstruction)
5) abnormal communication of the urinary tract (fistula)
6) incontinence due to more general impairment (e.g. cognitive, functional, affective) (functional incontinence)
Describe the phases of bladder filling and emptying?
Continence is maintained by the co-ordinated interaction of the bladder, urethra, pelvic floor muscles and the nervous system.
The bladder is a low pressure - high volume system: the bladder pressure increases slowly as the bladder fills.
Continence is maintained as long as the urethral pressure exceeds bladder pressure:
1) Storage phase:
- bladder fills and the urethra and pelvic floor contract
- first urge to void occurs at about 250ml, at this point the urethra and pelvic floor contract more
2) Emptying phase:
- when the bladder volume reaches the normal urge to void there is voluntary relaxation of the urethral smooth muscle that reduces urethral pressure
- pelvic floor relaxes
- bladder pressure increases as a result of detrusor contraction
3) Storage phase
What is the detrusor muscle?
The detrusor muscle is a layer of the urinary bladder wall made of smooth muscle fibres arranged in spiral, longitudinal and circular bundles.
Stretching of the bladder wall signals the parasympathetic nervous system to contract the detrusor muscle.
The trigone is....
...a smooth triangular area on the inner surface of the bladder. The triangle is formed by 2 ureteral orifices and the internal urethral orifice.
Where is the external urethral sphincter located?
The external urethral sphincter is located at the bladders distal inferior end in females and inferior to the prostate in males.
It is made up of striated muscle and is therefore under voluntary control.
What is the internal urethral sphincter?
The internal urethral sphincter is found at the junction between the bladder and the urethra. It is a continuation of the detrusor muscle and hence made of smooth muscle. It is only present in males.
What is the periurethral striated muscle?
This is striated muscle that forms part of the pelvic diaphragm.
What is the micturition cycle? What parts of the nervous system are involved?
The micturition cycle involves both somatic (voluntary) and autonomic nervous systems.
Voluntary control comes from the frontal cortex. The pontine micturition centre (midbrain) co-ordinates detrusor contraction with urethral relaxation.
What controls bladder contraction?
Bladder contraction is mediated by the parasympathetic system. These parasympathetic fibres, along with those responsible for somatic control, originate from the sacral plexus (S2 to S4).
Excitation of the parasympathetic nerves in response to bladder filling stimulates acetylcholine release which acts at M3 muscarinic receptors causing detrusor muscle contraction.
What mediates bladder relaxation/ filling?
Bladder filling is mediated by the sympathetic system. Sympathetic nerves arise from T11 to L2 and innervate the smooth muscle of the bladder neck and proximal urethra causing contraction allowing the bladder to fill.
Excitation of the pudendal nerve causes contraction of the external urethral sphincter, allowing voluntary control.
Describe the micturition cycle from bladder filling?
During the storage phase, the bladder fills with only small increases in pressure. Sympathetic nerves from T11-L2 travel within the hypogastric nerves and synapse in the inferior mesenteric ganglion whence they innervate the bladder neck and proximal urethra causing contraction, allowing the bladder to fill.
Stretching the urinary bladder increases the frequency of action potentials travelling in sensory neurons to the spinal micturition centre (S2-S4) in the sacral region of the spinal cord. This increases parasympathetic outflow to the detrusor muscle and bladder neck via pelvic parasympathetic nerves (S2-S4) which causes contraction. This is INVOLUNTARY.
Sensory signals also ascend to the pontine micturition centre causing a conscious desire to urinate. If urination is convenient, then descending fibres activate sacral somatic motor neurons which cause relaxation of the external urethral sphincter, allowing micturition to take place.
What type of incontinence do alpha blockers cause?
Alpha blockers such as doxazosin block adrenergic stimulation of the external urethral sphincter, bladder neck and proximal urethra, resulting in decreased tone and consequent stress incontinence.
A patient presents with symptoms of urgency associated with occasional incontinence. Their bladder function is normal between times. What is the most likely diagnosis?
This is classic of overactive bladder. Remember this is a syndrome including urinary urgency +/- urge incontinence (which is the involuntary leakage of urine accompanied or preceded by urgency).
A patient is started on amitriptylline for depression. They develop incontinence following this. What is the most likely cause of their incontinence?
Amitriptylline is a TCA and has anti-muscarinic side effects. Detrusor contraction is maintained by parasympathetic muscarinic fibres, which are inhibited by anti-muscarinic agents. As a result, patients tend to retain urine and develop overflow incontinence.
What screening tools can be used to assess incontinence issues in older people?
All elderly patients should be asked about bladder and bowel problems. If they report a problem then a more objective assessment is required. The B-SAQ (Bladder Control Self Assessment Questionnaire) is a useful questionnaire that patients can fill out. It gives both a "symptom score" which confirms the presence of a urinary problem and a "bother score" which assesses how much their symptoms affect the patient.
What a storage symptoms?
Continual urine loss
Frequency of micturition
Name some voiding symptoms?
Post micturition dribble
What are some co-morbid conditions that can lead to incontinence?
What are some important consequences of incontinence?
Admission to care homes
Reduced quality of life
Examination in a patient with incontinence?
- AMT if concerns regarding cognitive impairment
- look for clues and assess gait
- check dorsiflexion of the toes (S3) and perineal sensation (L1-2) and sensation over the posterior aspect of the thigh (S3)
- palpate for enlarged kidneys
- palpate abdomen for distended bladder
- DRE for anal tone
- inspect for vaginal atrophy or prolapse
- assess pelvic floor muscle strength (e.g. Oxford classification)
- signs of chronic lung disease or CCF
What simple investigations should be performed on a patient presenting with incontinence?
Investigations for incontinence can be divided into simple and specialist. Simple investigations include:
1) Frequency/ volume charts:
- ask a patient to keep a diary over 3 days recording fluid intake, volume of urine passed and episodes of incontinence
- check for glucose (diabetes), protein (renal pathology), leucocytes and nitrates (infection), haematuria (stones or malignancy)
- FBC, leucocytosis may indicate infection
- U&Es, determine renal function
- Glucose, rule out diabetes
- Calcium, rule out hypercalcaemia which can cause constipation and confusion
What imaging modalities can be used to help investigate incontinence?
A post void bladder scan is an essential first line investigation and should be performed to rule out chronic retention of urine.
Other imaging modalities are not routinely indicated unless there are specific indications:
- USS abdo: requested if renal failure to evaluate kidney size and look for signs of obstructive uropathy
- CT urography: requested if considering renal stones
- CT abdo: to exclude abdominal or pelvic masses if these are suspected
- Intravenous urogram: useful if renal stones are suspected, but most centres use CT urography now
What should be ruled out prior to referral for more complex investigations in incontinence?
It is essential to rule out UTI before referring for complex investigations.
What trends are useful to look out for in frequency volume charts?
1) Frequent small volumes of urine - suggests OVERACTIVE BLADDER
2) >1/3 of total urine volume voided at night - suggests NOCTURNAL POLYURIA
3) >2500ml urine/day - indicates POLYURIA
4) Excessive intake of fluid or increased fluid intake in the evening - could lead to increased frequency
What is uroflowmetry?
Of the specialist investigations that patients with incontinence can be referred for, this is perhaps one of the more simple ones. It basically measures urine flow rate.
It is a non invasive and useful technique for diagnosing bladder outlet obstruction. A commode, rotating disc flowmeter, computer and bladder scanner are required.
In reference to uroflowmetry, define the following terms:
1) Flow time
2) Maximum flow rate
3) Time to maximum flow
4) Volume voided
1) Flow time = time during which measurable flow occurs, whereas the voiding time is the total duration of voiding including any interruptions
2) Maximum flow rate = maximum measured flow rate, Qmax, varies with age (decreases) and sex
3) Time to maximum flow
4) Volume voided = total volume voided through the urethra. A voided volume of >150ml is required for accurate interpretation
Normal results are indicated by a smooth parabolic curve on the uroflowmetry trace.
What is a "fast bladder"?
This is a trace seen on uroflowmetry (remember this is a plot of flow rate vs time).
Fast bladder traces show an exaggerated flow rate and a decreased time to Qmax which can be found in patients with stress incontinence or problematic detrusor overactivity.
What type of uroflowmetry trace is consistent with bladder outflow obstruction?
A prolonged flow trace is consistent with bladder outflow obstruction. There is a prolonged flow time and a low Qmax.
What is an ultrasound cystodynamogram?
This test basically combines uroflometry with pre and post void bladder scans. These combined tests give information about functional bladder capacity, flow rate and post void bladder volume.
If after uroflometry +/- pre and post void bladder scans the diagnosis is still uncertain, more specialised tests should be considered - e.g. cystometry
What is cystometry?
This refers to measurement of bladder pressure, sensation, capacity and compliance during filling and voiding.
The bladder is filled with saline at room temperature via a small bore urethral catheter which is passed along with a bladder transducer. A further pressure transducer is placed in the rectum. Pressure is recorded as the bladder is filled.
In pressure urodynamics, how is true intravesical pressure calculated?
Intravesical pressure - rectal pressure
Transient rises in intra-abdominal pressure causes transient rises in intra-vesical pressure which can distort pressure urodynamic recordings. A way around this is to record rectal pressures using a rectal transducer as a proxy for intra-abdominal pressure and subtract it from the intra-vesical pressure.
Name some transient, reversible causes of incontinence?
These can be remembered by the mnemonic "DIAPPERS":
- Delirium: patients with acute confusional state often develop urinary incontinence
- Infection: urinary tract infection can cause bladder irritation
- Atrophy: vaginal atrophy is associated with urinary incontinence
- Psychological: several psychiatric diagnoses can lead to incontinence including depression and dementia
- Excess urine output: e.g. diabetes or excess fluid intake
- Restricted mobility
- Stool impaction: essential to rule out constipation as a cause of urinary incontinence, don't forget a DRE