Urinary Incontinence

Involuntary leakage of urine

Aetiology

  • Stress incontinence: involuntary leakage of urine on effort or exertion, or on sneezing or coughing
    • Occurs due to urethral hypermobility (impaired pelvic floor support) or intrisic sphincter deficiency (denervation or weakness of sphincter mechanism)
    • It is typically seen after childbirth, which is the most common causative factor, having resulted in denervation of the pelvic floor
    • Other risk factors include oestrogen deficient states, pelvic surgery and irradiation
    • May be associated with genitourinary prolapse
  • Urge incontinence: involuntary urine leakage accompanied by, or immediately preceded by, urgency of micturition
    • Caused by detrusor instability or hyperreflexia leading to involuntary detrusor contraction
    • This may be idiopathic or secondary to neurological problems such as stroke, Parkinson's disease, multiple sclerosis, dementia or spinal cord injury
  • Mixed incontinence: involuntary leakage of urine associated with both urgency and exertion, effort, sneezing or coughing
  • Overactive bladder syndrome: urgency that occurs with or without urge incontinence and usually with frequency and nocturia
    • May be called 'OAB wet' or 'OAB dry', depending on whether or not the urgency is associated with incontinence
    • Usually caused by detrusor overactivity - normally idiopathic, can be neurogenic (e.g. MS) or secondary to pelvic floor/incontinence surgery

Risk factors

  • Increasing age - peak incidence around menopause
  • Obesity
  • Parity and mode of delivery
    • More children = increased risk
    • C/section may be protective
  • HRT
  • Hysterectomy
  • Diet
  • Smoking
  • Exercise (high impact e.g. gymnastics)
  • UTI

Clinical presentation

Symptoms

  • Stress incontinence: leakage provoked by activity, coughing, laughing, sneezing, penetration etc.
  • Urge incontinence: describes the sensation of urgently needing to pass urine, resulting in involuntary leakage
  • Overactive bladder: frequency, urgency with or without incontinence, nocturia, nocturnal enuresis, provoked by cold, running taps, key in lock

Examinations

  • BMI
  • Mobility
  • Abdominal palpation
  • Inspection external genitalia
  • Assess for prolapse
  • Assess for pelvic floor squeeze
  • Neuro exam if appropriate

Investigations

  • Urinalysis +/- culture to check for UTI
  • Frequency volume chart: 3 days
  • Ultrasound
  • Cystoscopy
  • Urodynamics

Management

Stress incontinence

  • Conservative: weight management, pelvic floor muscle training, incontinence ring
  • Medical: vaginal oestrogen, duloxetine (last line - after surgical)
  • Surgical: bulking agents, fascial slings, colposuspension

Urge incontinence and overactive bladder

  • Conservative: fluid management, weight management, bladder retraining
  • Medical: vaginal oestrogen, anticholinergics (tolterodine, soliphenacin), β3-adrenoceptor agonist (mirabegron), desmopressin (nocturia)
    • Anticholinergics inhibit involuntary contraction - stops detrusor from contracting inappropriately by blocking the antimuscarinic receptors
    • Mirabegron increases relaxation of detrusor by activating the Mg receptors
  • Surgical: botox, percutaneous posterior tibial nerve stimulation (after MDT and failed botox), augmentation cystoplasty (last resort)