Urinary incontinence

Epidemiology

Stress incontinence and mixed incontinence are the most common types of incontinence in female patients.
Urge incontinence is the most common type in male patients.

Etiology

Neurological causes
- Multiple sclerosis
- Spinal injury
- Normal pressure hydrocephalus
Genitourinary causes
- Trauma to the pelvic floor
- Intrinsic sphincter deficiency
- Urethral hypermobility in women
- Impaired detrusor contractility
- Bladder outlet obstruction
- Pelvic floor weakness
Transient causes of urinary incontinence
- Drugs (e.g., diuretics)
- Urinary tract infections
- Postmenopausal atrophic urethritis
- Psychiatric causes (especially depression, delirium/confused state)
- Excessive urinary output (in conditions like hyperglycemia, hypercalcemia, CHF)
- Stool impaction
General risk factors
- Recurrent urinary tract infections

Mnemonic

To remember the reversible causes of acute urinary incontinence, think DIAPPERS: Delirium/confusion, Infection, Atrophic urethritis/vaginitis, Pharmaceutical, Psychiatric causes (especially depression), Excessive urinary output (hyperglycemia, hypercalcemia, CHF), Restricted mobility, Stool impaction.

Classifications

Overflow incontinence

Mechanism

Impaired (weak) detrusor contractility
Bladder outlet obstruction (e.g., BPH)
Both mechanisms can lead to incomplete bladder emptying → bladder overfilling → chronically distended bladder with ↑ bladder pressure → dribbling of urine (leak) when intravesical pressure > outlet resistance

Clinical features

Frequent, involuntary intermittent/continuous dribbling of urine in the absence of an urge to urinate
Occurs only when the bladder is full
Postvoid residual urine volume (seen on ultrasound or with catherization)
- Assess for urinary retention via bladder scan (≥200 mL) or straight catheterization yielding ≥200 mL urine output.

Treatment

Intermittent catheterization: for scheduled bladder emptying
- Intermittent -> prevention of catheter-associated UTIs and is favored by most patients; indwelling catheters may be considered if necessary.

Epidemiology

Prevalence increases with age.

Etiology

Pathomechanism: outlet incompetence
- Urethral hypermobility: loss of pelvic floor musculature and/or connective tissue support → weak pelvic floor → inability of the urethra to completely close
- Intrinsic sphincter deficiency
Risk factors
- Multipara
- Pregnancy and vaginal deliveries
- High-impact activity (e.g., jumping, running, hopping)
- Menopause
- Obesity
- Smoking
- Chronic cough (e.g., COPD)
- Prostate or pelvic surgery

Pathophysiology

Clinical features

Physical activity that causes increased intra-abdominal pressure (e.g., laughing, sneezing, coughing, exercising) leads to loss of urine
Frequent, predictable, small-volume urine losses with no urge to urinate prior to the leakage

Diagnostics

Treatment

Conservative treatment

Kegel exercises
- Strengthen Levator ani
Lifestyle changes (e.g., weight loss, avoiding alcohol and caffeine, smoking cessation)
Vaginal pessary

Surgical procedures

Indicated if conservative treatment does not provide sufficient improvement of symptoms
Procedure of choice: midurethral sling to elevate the urethra

Epidemiology

Prevalence increases with age

Etiology

The condition is caused by sensory or motor dysfunction.

Idiopathic (most common)
Neurological conditions

Pathophysiology

Inflammatory conditions (e.g., UTI) or neurogenic disorders → sphincter dysfunction, detrusor overactivity, or overactive bladder → autonomous contractions of the detrusor muscle and premature initiation of a normal micturition reflex

Clinical features

Urinary urgency: sudden urge to urinate
Loss of urine without exertion, with urinary tenesmus → frequent episodes, with variable volumes of urine voided each time

Diagnostics

Treatment

Mnemonic

Oxybutynin treats Overactive bladder.

Neurogenic bladder dysfunction

Mechanism

detrusor sphincter dyssynergia

Simultaneous contractions of the detrusor muscle and involuntary activation of the urethral sphincter → blockage of bladder outlet → small amounts of urine are pressed through the contracted sphincter muscle → high intravesical pressure along with inappropriate contraction of the urethral sphincter
Commonly seen in multiple sclerosis and spinal cord injury

Clinical features

Voiding and/or storage dysfunction, intermittent voiding, urinary retention
Irregular, small volume incontinence without an associated urge to void (sometimes referred to as reflex incontinence)

Total incontinence

Complete loss of sphincter function (due to previous surgery, nerve damage, metastasis) → Urinary leakage occurs at all times

Clinical features

Diagnostics

Treatment

Overview of pharmacotherapy

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Warning

The use of muscarinic agonists may lead to urinary urgency, while the use of sympathomimetics or muscarinic antagonists may lead to urinary retention, especially if there is an untreated outlet obstruction.

Tip

No pharmacological therapies are FDA-approved for stress incontinence; treatment is primarily conservative with surgery.