Disorders of the Urinary Tract Flashcards
What occurs if there is increased uncontrolled detrusor pressure?
- Increases Bladder pressure beyond normal urethra → incontinence
- Most common cause: ‘Overactive bladder’ (OAB) AKA urinary urge incontinence (prev. called detrusor instability)
What occurs if there is increased intra-abdominal pressure?
- Transmitted to bladder but not urethra, because upper urethra neck no longer in abdomen
- Bladder pressure > urethral pressure when → abdominal pressure e.g. coughing
- Most common cause: ‘Urinary stress incontinence’
What are some rare causes of urinary incontinence?
Urine bypassing sphincter through fistula
Pressure of urine overwhelming the sphincter due to overfilling of bladder - neurogenic or outlet obstruction = Outflow Incontinence
Define daytime frequency.
Number of voids during waking hours
Normally 4-7x daily
Defined as when patient perceives number of voids as too often
Define nocturia.
Waking at night >1 time to void in those under 70
Define urgency.
Sudden compelling desire to pass urine, which is difficult to defer
Most frequently secondary to detrusor overactivity
Inflammatory bladder conditions e.g. interstitial cystitis may present with urgency
What are the investigations of the urinary tract?
- Urine dipstick
- Urinary diary
- Post-micturition USS or catheterisation - exclude chronic urine retention
- Urodynamic studies (cystometry)
- Ultrasonography - exclude incomplete emptying, also checks for congenital abnormalities, calculi, tumours and detects cortical scarring of kidneys
- Abdominal XR - foreign bodies and calculi
- CT urograms - integrity and route of ureter with contrast
- Methylene dye test - o Blue dye instilled into bladder
o Leakage from places other than the urethra seen e.g. fistulae - Cystoscopy - inspection of bladder cavity - exclude tumours, stones, fistulae and interstitial cystitis
What is this cystometry showing?
What are these showing?
Define urinary stress incontinence.
Involuntary leakage of urine on effort or exertion, or on sneezing/coughing
What are the risk factors of stress incontinence?
- Increasing age.
- Pregnancy and vaginal delivery — muscles and connective tissue can be weakened during delivery, and damage may occur to pudendal and pelvic nerves.
- Obesity — due to pressure on pelvic tissues and stretching and weakening of muscles and nerves from excess weight.
- Constipation — straining may weaken pelvic floor muscles.
- A deficiency in supporting tissues for example:
- Prolapse — not a cause of stress urinary incontinence but may be caused by the same underlying deficiency of supporting tissues.
- Hysterectomy — surgery may damage the pelvic floor muscles.
- Lack of oestrogen at the menopause — oestrogens keep tissues that influence normal pressure transmission in the urethra healthy and maintain urethral secretions that help to create a ‘seal’.
- Family history — women whose mother or sisters are incontinent are more likely to develop stress urinary incontinence.
- Smoking — smoking is associated with chronic cough which may contribute to stress urinary incontinence.
- Drugs — for example angiotensin-converting enzyme (ACE) inhibitors (can cause cough and worsen stress incontinence).
Describe the mechanism of stress urinary incontinence?
Increased Intra-adbominal pressure → compression of bladder → Increased bladder pressure → bladder > urethral pressure → incontinence
What should you assess in stress urinary incontinence?
o Assess how life is disrupted
o Stress incontinence = major symptom
o Frequency, urgency or urge incontinence may also occur
o Faecal incontinence due to childbirth injury may coexist
How should you investigate stress urinary incontinence?
- Urine testing → UTI
- Assessing residual urine - post micturition USS
- Urinary diary: frequent passage of small volumes of urine particularly at night
- Cystometry: demonstrates contractions on filling or provocation with detrusor overactivity
How should we manage stress urinary incontinence?
- Note = stress incontinence is due to pelvic floor weakness / intrinsic sphincter deficiency
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Conservative:
- avoid caffeinated drinks,
- avoid drinking either excessive/reduced amounts of fluids daily,
- weight loss if BMI > 30kg/m2
- smoking cessation if applicable
- Provide info on NHS.uk website
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1st line: Offer referral for Pelvic floor muscle training to appropriate practitioner
- Supervised training involving least 8 contractions performed 3 times per day for a minimum of 3 months
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2nd line: Surgical procedures (only initiated by 2° services)
- Colposuspension - sutures are used to lift the neck of the bladder and fix in place to Cooper’s ligaments
- Autologous rectus fascial sling - elevate the urethra
- Retropubic mid-urethral mesh sling - elevate the urethra
- Intramural urethral bulking agents - injection of a bulking agent around the urethra
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3rd line: Duloxetine (enhances sphincter contraction) then r/v in 2-4 weeks if unsuitable for surgery/prefer pharmacological to surgical Rx
- SNRI - Enhances urethral striated sphincter activity via centrally mediated pathway