Incontinence And Micturition

Question 1

What are the types of urinary incontinence?

Answer 1

Stress urinary incontinence - leakage in effort or exertion such as coughing.
Urgency incontinence - leakage proceeded immediately by urgency.
Mixed urinary incontinence - combination of stress and urgency.
Overflow incontinence - involuntary release of urine when the bladder becomes overly full.

Question 2

What is overactive bladder?

Answer 2

Frequent and sudden urge to urinate that might be difficult to control. Can be wet (with incontinence) or dry.

Question 3

What risk factors are there for urinary incontinence?

Answer 3

Pregnancy and childbirth,
Menopause,
Obesity,
Much more common in women than men.

Question 4

What examinations can be done to determine the cause of incontinence?

Answer 4

BMI,
Abdominal examination for palpable bladder,
Examine S2-4 dermatomes,
Digital rectal examination for men,
Vaginal exam and stress test for women.

Question 5

What investigations are there for incontinence?

Answer 5

Urine dipstick - mandatory - checks for UTI, haematuria, proteinuria, glucosuria.
Frequency volume charts and bladder diaries.
Cystoscope or pad tests.

Question 6

How are pressure flow studies conducted?

Answer 6

Probe is placed into bladder to measure intravesicle pressure and probe into rectum for intraabdominal pressure. Fluid is pumped into the bladder and pressure changes are measured against volume.

Question 7

How is detrusor pressure calculated in uridynamic testing?

Answer 7

Intravesicle pressure - abdominal pressure. Should only rise when voiding. Should not rise when coughing.

Question 8

What lifestyle interventions lessen urinary incontinence?

Answer 8

Modifying fluid intake,
Weight loss,
Decreased caffeine intake (UUI),
Timed voiding.

Question 9

What is contained incontinence?

Answer 9

Incontinence is captured using pads, Indwelling catheter or sheath device (similar to a condom attached to catheter bag).

Question 10

What specific management targets stress urinary incontinence?

Answer 10

Pelvic floor muscle training,
Duloxetine - combined noradrenaline and serotonin uptake inhibitor. Increases activity of the external urethral sphincter.

Question 11

What surgical options are there for stress urinary incontinence?

Answer 11

Women - open retropubic sling procedures, low tension vaginal tapes.
Men - artificial urinary sphincter, male sling procedure.

Question 12

What management options are there for urge urinary incontinence?

Answer 12

Bladder training,
Anticholinergics,
B3 adrenoreceptor agonists (increase bladder ability to store urine),
Botox injections.

Question 13

What surgical options are there for urge urinary incontinence?

Answer 13

Sacral nerve neuromodulation, augmentation cystoplasty, urinary diversion.

Question 14

How is bedwetting defined? How is it managed?

Answer 14

Involuntary wetting during sleep at least 2x per week in children over 5 with no CNS symptoms.
Managed with reassurance and positive reward systems, or by treating the underlying cause.

Question 15

What sphincters prevent the leakage of urine?

Answer 15

External urethral sphincter - skeletal muscle - found in pelvic diaphragm.
Internal urethral sphincter - only prominent in men - smooth muscle - also prevents retrograde ejaculation.

Question 16

At what volume does pressure start to increase rapidly in the bladder?
At what volume does the urge to urinate become very strong?

Answer 16

150ml.

500ml.

Question 17

What is the neurological pathway of the storage reflex (in men)?

Answer 17

Stretch receptors - sensory neurone - enters sacral cord S2-4 - Ascends spinal cord to T10-L2 - synapses to sympathetic preganglionic neurone - postganglionic - inhibits detrusor muscle and excites internal urethral sphincter.

Question 18

How is the external sphincter controlled?

What centre of the brain helps regulate this?

Answer 18

Somatically via the pudendal nerve with excitatory effect. L centre neurones on the brainstem send axons down to innervate the pudendal nerve and keep the sphincter closed.

Question 19

What is the neurological pathway of the voiding reflex?

Answer 19

Stretch receptors - sensory neurone -enter sacral cord S2-4 - synapse to parasympathetic neurone - one preganglionic, short postganglionic - postganglionic acts on detrusor muscle to stimulate contraction.

Question 20

How does the M centre exert positive feedback on the voiding reflex?

Answer 20

Excite neurones that stimulate contraction of the detrusor muscle, which also feedback to the M centre and activate it further.

Question 21

How does the M centre ensure that there is no activation of both centres at the same time?

Answer 21

Sends inhibitory signals via neurones to the L centre, relaxing the external urethral sphincter.