Overactive Bladder (OAB) with Urinary Incontinence
OAB wet is defined as overactive bladder syndrome with urinary incontinence, specifically characterized by urgency urinary incontinence (UUI), which is the involuntary leakage of urine associated with a sudden compelling desire to void that is difficult to defer. 1
Key Characteristics of OAB Wet
Core Symptoms
- Urgency urinary incontinence (UUI): Involuntary leakage of urine associated with a sudden compelling desire to void
- Urinary frequency: Often more than 7 micturitions during waking hours
- Nocturia: Interruption of sleep one or more times to void
- Urgency: The hallmark symptom of OAB, defined as a sudden compelling desire to pass urine that is difficult to defer 1
Distinguishing Features
- OAB wet (with incontinence) vs. OAB dry (without incontinence)
- Small volume voids are typical with OAB wet, as opposed to normal or large volume voids seen in conditions like nocturnal polyuria 1
- Must be differentiated from other types of incontinence:
- Stress urinary incontinence (leakage with physical exertion)
- Mixed urinary incontinence (combination of stress and urgency incontinence) 2
Diagnosis
Required Assessment
- History: Document duration and baseline symptom levels
- Physical examination: Including abdominal, genitourinary, and lower extremity assessment
- Urinalysis: To rule out UTI and hematuria 1
Optional Additional Assessment
- Urine culture: If UTI is suspected
- Post-void residual measurement: To assess for urinary retention
- Voiding diary: To document frequency, timing, and volume of voids
- Symptom questionnaires: To quantify symptom severity 1, 2
Treatment Algorithm
First-Line: Behavioral Therapy
- Patient education: Explain normal urinary tract function and treatment goals
- Bladder training: Timed voiding and gradual extension of voiding intervals
- Fluid management: Appropriate timing and volume of fluid intake
- Pelvic floor muscle training: Especially beneficial for mixed incontinence 1, 2
Second-Line: Pharmacologic Management
If behavioral therapy is insufficient after an appropriate trial period:
Antimuscarinic medications:
- Starting with lower doses to minimize side effects (dry mouth, constipation)
- Consider dose modification or alternate antimuscarinic if side effects are intolerable 1
Beta-3 adrenergic receptor agonists (e.g., mirabegron):
Combination therapy:
- Consider combining an antimuscarinic with a beta-3 agonist if monotherapy is partially effective 1
Third-Line: Advanced Therapies (for refractory cases)
- Specialist referral and reassessment
- Botulinum toxin injections: Consider in severe cases (note: may require intermittent self-catheterization)
- Neuromodulation: Sacral nerve stimulation or tibial nerve stimulation
- Surgical options: Rarely, augmentation cystoplasty for extreme cases 1, 4
Important Considerations
Monitoring and Follow-up
- Regular assessment of treatment response
- Monitoring for adverse effects, particularly with antimuscarinic medications
- Blood pressure monitoring with mirabegron therapy 3
Cautions
- Antimuscarinic medications may cause urinary retention, especially in patients with bladder outlet obstruction
- Mirabegron may increase blood pressure and is not recommended in severe hepatic or renal impairment 3
- Approximately 30% of patients may continue to experience urgency symptoms even after successful treatment of other urinary conditions 2
Quality of Life Impact
OAB wet significantly impacts quality of life through:
- Disruption of daily activities and social interactions
- Sleep disturbances due to nocturia
- Anxiety about potential incontinence episodes
- Reduced participation in physical activities 2
By understanding OAB wet as a distinct clinical entity with specific diagnostic criteria and treatment options, clinicians can provide targeted therapy to improve symptoms and quality of life for affected patients.