Urinary retention + incontinence

Question 1

Urinary retention + causes

Answer 1

• Urinary retention: can’t go to toilet.
• Causes:
  (i) post surgery anaesthesia, following epidural or spinal anaesthesia
• temporary inhibition of micturition reflex
• treatment → may require urinary catheter. Will recover w/ time.
  (ii) outflow obstruction (eg prostate disease) → overflow leakage
• treatment → urinary catheter.
• may require prostate resection (TURP: transurethral resection of prostate)
  (iii) urethral stricture: commonly seen in young men following accidents (eg bike accidents)
• damage to urethra → scarring, stenosis (constriction)
• can be temporary or permanent. Treatment is balloon dilation of urethra

Question 2

Stress incontinence

Answer 2

• Stress incontinence: sphincter control
• causes: obstetric injury, pelvic floor weakness, peripheral nerve damage
• increased pressure → urination; eg when someone coughs or laughs or lifts heavy object

Question 3

Neurogenic incontinence:

1) uninhibited neurogenic bladder

Answer 3

• Normal descending inhibitory (storage) control from PSC impaired.
• However, “facilitatory” descending pathways that allow sphincter opening & bladder contraction are still functioning.
• The balance shifts to micturition
  → frequent, uncontrollable micturition reflex
• Patient aware of need to void
• Cause: interruption of “inhibitory” descending pathways that impede sphincter opening + bladder contraction
• Seen in stroke, brain injury, multiple sclerosis, Parkinson’s disease
• In infants, the descending inhibitory tracts are not fully developed with similar symptoms (infant’s bladder).

Question 4

Neurogenic incontinence:

2) automatic bladder

Answer 4

• Cause: loss of ascending spinal sensory & descending motor nerve tracts
• see initially after complete transection of the spinal cord above the sacral segments
• Eliminates voluntary + supraspinal control of urination
• initially urinary retention
• no awareness
• Later automatic micturition & detrusor overactivity
• spinal reflex emerges
• voiding inefficient due to simultaneous contraction of bladder + internal sphincter (detrusor-sphincter dysfunction)

Question 5

Neurogenic incontinence:

(3) atonic bladder

Answer 5

• Damage to peripheral sensory &/or motor bladder nerves
• Causes: peripheral nerve injury, damage during pelvic surgery, diabetes (peripheral neuropathy), bladder infection.
• Loss of awareness or desire to urinate (if damage to sensory).
• Bladder does not empty
• bladder becomes stretched by excess urine build up, damages the bladder wall
• overflow leakage