Overactive Bladder (OAB)

 

What is an Over active bladder?

  • OAB refers to a bladder condition that results in urinary symptoms including:
    • Urgency – sudden strong desire to void that is difficult to defer
    • Urge incontinence – urgency followed by urinary leakage
    • Frequency – frequent passage of urine (usually >hourly)
    • Nocturia – need to wake from sleep to pass urine

What causes an overactive bladder?

  • In most cases, no cause is identifiable (idiopathic).
  • Some neurological conditions can cause symptoms of OAB including:
    • Stroke
    • Multiple sclerosis
    • Parkinson’s
    • Dementia
  • Other risk factors for developing OAB include:
    • Increasing age
    • Bladder inflammation including recurrent urinary tract infections
    • Pregnancy
    • Post menopausal state
  • OAB symptoms can also be caused as a result of bladder obstruction from an enlarged prostate (see section on benign prostatic hypertrophy/BPH)

How is OAB diagnosed?

  • In most cases, OAB can be diagnosed with a thorough history of the symptoms, examination and some baseline tests.  Occasionally, more complex/invasive tests will be required.
  • Baseline tests routinely needed include:
    • Urine culture – to exclude an infection
    • Basic blood tests – to check kidney function
    • Kidney tract ultrasound – to check bladder emptying and exclude any conditions that may mimic OAB such as bladder stone or bladder cancer
    • Bladder diary – is a useful history of 1-2 days of fluid intake and voiding patterns. It will give a more accurate idea of the frequency and volume of voids as well as fluids consumed.
  • Other tests sometimes needed include:
    • Cystoscopy – telescopic inspection of the urethra and bladder. May be required if history of infections, blood in the urine (haematuria) or atypical symptoms not responding to initial treatment
    • Urodynamics – for details see Urological Procedures explained.  Essentially is a pressure test of the bladder during simulated filling and voiding. Helps confirm the diagnosis of OAB and me required if medications has failed prior to surgical treatments.

What are the treatment options for OAB?

  • Fortunately, many effective treatment options now exist for OAB.  Most patients will have significant improvement with oral medication alone, whilst a minority will require minimally invasive procedures.  Rarely, major surgery is required if the above options have failed (but this is very uncommon).
  • Treatment options from least to most invasive include:
    • Lifestyle modifications:
      • Avoiding precipitant foods or fluids that seem to worsen symptoms (caffeine & alcohol in particular)
      • Modification of fluid intake to reduce symptoms at inconvenient times
      • Weight loss programs may help
    • Bladder retraining (see patient resources for details)
    • Medications: most patients suspected of having OAB will trial anticholinergic medications at some stage.  There are many different types of these medications on the market. Commonly used examples include: Ditropan (Oxybutynin), Vesicare (Solifenacin), Oxytrol patches (Oxybutynin skin patch)
      • Anticholinergic medications work by essentially “dampening down” the nerve supply to the bladder to reduce the urge and need to void.  They aim to both decrease the frequency of voiding and decrease the urge to void, allowing more time to reach the toilet.
      • These agents are usually well tolerated however the most common side effects include: dry mouth, constipation, minor blurred vision. Less common side effects include: confusion, dizziness, rapid heart-beat, and urinary retention (unable to pass urine).
      • Anticholinergics are contraindicated if you have certain types of glaucoma (narrow angle).
    • Minimally invasive surgical options
      • These are usually reserved for when oral medications have failed
      • Options include:
        • Bladder Botox injections
          • This involves a cystoscopy under anaesthesia. 20-30 injections are administered into the bladder wall
          • Botox is usually very successful in improving symptoms, however the effects will wear off with time and repeat injections are required every 6-12 months
          • Sacral Neuromodulation: also often referred to as a bladder pacemaker.
            • Involves a trial stage and an implant stage
            • A small electrode is first inserted into the lower back (sacral spine) to lie next to a sacral nerve root.
            • if symptoms are improved with the trial then a permanent battery is implanted.
            • This is a uncommon procedure and if required you will be sent to a Urologist who subspecialises in this procedure
    • Major surgery options: fortunately these are rarely required these days, due to effectiveness of the above treatments. However occasionally may required and include:
      • Augmentation cystoplasty: a segment of small intestine is isolated and “patched” onto the bladder to increase the volume
      • Urinary diversion/ ileal conduit – essentially the last resort if all else fails. This involves diverting the urine away from the bladder, usually to an ileal conduit (short segment of small intestine that has been isolated) and drains via a stoma at the skin.  The bladder may or may not be removed if this is required.