urinary continence & BPH

Question 1

What are the filling phase and voiding phase of micturition?

Answer 1

• Filling phase: bladder fills & distends without rise in intravesical pressure. Urethral sphincter contracts & closes urethra.
• Voiding phase: bladder contracts to expel urine, urethral sphincter relaxes & urethra opens.

Question 2

What is difference in micturition in infants and adults?

Answer 2

• In infants micturition is local spinal reflex where bladder empties when it reaches critical pressure.
• In adults it can be initiated or inhibited by higher centre control of external urethral sphincter keeping it closed until it is appropriate to urinate.

Question 3

What is innervation involved in micturition?

Answer 3

• M3 receptors (parasympathetic S2-S4) are stimulated as the bladder fills.
• As they become stretched & stimulated results in contraction of detrusor muscle for urination.
• Parasympathetic fibres inhibit internal urethral sphincter relaxing it and allowing bladder emptying.
• When bladder empties stretch fibres inactivated and sympathetic nervous system (T11-L2) stimulated to activate beta-3 receptors causing relaxation of detrusor allowing bladder to fill

Question 4

What is stress incontinence?

Answer 4

Involuntary leakage on effort or exertion or sneezing/coughing.

Question 5

What are investigations for stress urinary incontinence?

Answer 5

History & exam, positive stress test (demonstrate loss of urine on examination), urodynamics (urinary leakage during increase in intra-abdominal pressure in absence of detrusor contraction).

Question 6

What is management for stress urinary incontinence?

Answer 6

• Non surgical physiotherapy with PFE.

- Surgical mid-urethral sling, colposuspension, periurethral bulking agents.

Question 7

What is urge urinary incontinence (overactive bladder)?

Answer 7

Urinary urgency usually with urinary frequency and nocturia, with or without urge urinary incontnience

Question 8

What is incidence of urge urinary incontinence?

Answer 8

16% in men and women over 40.

Question 9

What are risk factors for urge urinary incontinence?

Answer 9

Age, prolapse, increased BMI, IBS, bladder irritants (caffeine, nicotine)

Question 10

What is the pathology behind urge urinary incontinence?

Answer 10

• Involuntary detrusor muscle contractions.

- Cause can be idiopathic, neurogenic (loss of CNS inhibitory pathways) or bladder outlet obstruction

Question 11

What are symptoms of urge urinary incontinence?

Answer 11

Urgency, frequency, nocturia & urgency incontinence, impact on QOL - sleep disorders, anxiety, depression.

Question 12

What are investigations of urge urinary incontinence?

Answer 12

• Exclude infection with urine dipstick/MSU, voiding diaries, assess post-void residual, urodynamics, cytoscopy.
• Assess for enlarged prostate in men & prolapse in women

Question 13

What is management of urge urinary incontinence?

Answer 13

Behaviour/lifestyle changes, bladder retraining, anti-muscarinic drugs, beta-3 agonists, BOTOX, neuromodulation (PTNS/SNS), surgical augmentation cytoplasty & urinary diversion

Question 14

What is overflow incontinence?

Answer 14

Involuntary leakage of urine when bladder is full.

Question 15

What are causes of overflow incontinence?

Answer 15

Usually due to chronic retention secondary to obstruction or atonic bladder. Eg. Outlet obstruction (faecal impaction/BPH), under-active detrusor muscle, bladder neck stricture, urethral stricture, drug history of alpha-adrenergics, anti-cholinergics, sedative, bladder denervation following surgery

Question 16

What is continuous incontinence? Causes?

Answer 16

Continuous loss of urine all the time.

Can be due to vesicovaginal fistula, ectopic ureter (from kidney to urethra or vagina)

Question 17

What is functional incontinence?

Answer 17

Due to severe cognitive impairment or mobility limitations preventing use of the toilet. Bladder function otherwise normal.

Question 18

What is mixed urinary incontinence?

Answer 18

More than 1 type, usually in elderly

Question 19

What is benign prostatic hyperplasia? what is it a common cause of?

Answer 19

Non-malignant growth or hyperplasia of prostate tissue, common cause of lower urinary tract symptoms in men.

Question 20

What is incidence of BPH?

Answer 20

Increases with age, 50-60% fore males in 60s, increasing to 80-90% for those over 70 years old

Question 21

What are risk factors for BPH?

Answer 21

Hormonal effects of testosterone on prostate

Question 22

What is pathophysiology of BPH?

Answer 22

Hyperplasia of both lateral and median lobes leading to compression of urethra and thus bladder outflow obstruction. Hyperplasia of stroma (smooth muscle & fibrous tissue) & glands.

Question 23

What are signs and symptoms of BPH?

Answer 23

Hesitancy in starting urination, poor stream, dribbling post-micturition. Frequency, nocturia. Can present with acute retention

Question 24

What are other causes of symptoms of BPH and how do you exclude these causes?

Answer 24

-Bladder/prostate cancer, cauda equina, high pressure chronic retention, UTI/STI, prostatis, neurogenic bladder (secondary to PD, MS), urinary tract stones, urethral stricture.
To exclude, do abdo, pelvic and rectal examination

Question 25

What investigations for BPH?

Answer 25

• Urine dipstick/MCS, post void residual, voiding diary.
• Bloods: PSA prostate specific antigen - to predict prostate volume (with caution if concerned about cancer).
• Imaging –> ultrasound to assess upper renal tracts, flow studies/urodynamics, cytoscopy if worried about cancer

Question 26

What is management for BPH?

Answer 26

• Lifestyle (weight loss, reduce caffeine and fluids in evening, avoid constipation)
• medical –>
  1. alpha blocker - alpha 1-AR present on prostate stromal smooth muscle & bladder neck with blockage resulting in relaxation so improves urinary flow rate
  2. 5-alpha reductase inhibitor - prevents conversion of testosterone to DHT (which promotes growth of prostate) so results in shrinkage and improves urinary flow and obstructive symptoms
  3. surgery - transurethral resection of prostate (TURP) which debulks prostate to produce adequate channel for urinary flow

Question 27

What are complications of BPH?

Answer 27

• Progressive bladder distention causing chronic painless retention & overflow incontinence.
• If undetected can lead to bilateral upper tract obstruction & renal impairment with patient presenting with chronic renal disease