What are the causes and treatments of urinary retention?

Causes and Treatments of Urinary Retention

Urinary retention is the inability to voluntarily void urine, which can be acute or chronic, with benign prostatic hyperplasia (BPH) being the most common cause, accounting for approximately 53% of cases. 1

Classification of Urinary Retention

Acute vs. Chronic Urinary Retention

• Acute urinary retention presents with sudden inability to void, often with hypogastric pain and anuria 2
• Chronic urinary retention is defined as post-void residual (PVR) volume greater than 300 mL measured on two separate occasions and persisting for at least six months 1

Major Causes of Urinary Retention

Obstructive Causes

• Benign prostatic hyperplasia (BPH) - most common cause overall, affecting primarily men 1
• Prostate cancer or other pelvic malignancies 3
• Urethral strictures or foreign bodies 3
• Pelvic organ prolapse in women 3

Neurologic Causes

• Spinal cord injuries or lesions affecting sacral nerves S2-S4 4
• Multiple sclerosis 4
• Parkinson's disease 4
• Cerebrovascular accidents (stroke) - affects approximately 25-50% of stroke survivors 4
• Diabetic neuropathy 3

Infectious and Inflammatory Causes

• Prostatitis 3
• Cystitis 3
• Urethritis 3

Pharmacologic Causes

• Anticholinergic medications (antipsychotics, antidepressants, respiratory agents) 5
• Alpha-adrenergic agonists 5
• Opioids and anesthetics 5
• Benzodiazepines 5
• NSAIDs 5
• Calcium channel antagonists 5
• Sympathomimetic agents like lisdexamfetamine that stimulate alpha-adrenergic receptors in the bladder neck and urethra 6

Evaluation of Urinary Retention

• Detailed medication history including prescription drugs, OTC medications, and herbal supplements 1
• Focused physical examination with neurological evaluation 1
• Measurement of post-void residual (PVR) volume 1
• Assessment for risk factors such as male gender, advanced age, and pre-existing lower urinary tract symptoms 6

Treatment Approaches

Initial Management

• Prompt and complete bladder decompression via catheterization is the first-line treatment for acute urinary retention 3, 1
• Suprapubic catheterization may be superior to urethral catheterization for short-term management, improving patient comfort and decreasing bacteriuria 1
• Silver alloy-impregnated catheters have been shown to reduce urinary tract infections 3

Pharmacological Management

• For BPH-related retention:

  • Alpha-blockers (e.g., tamsulosin) should be started at the time of catheter insertion to increase chances of returning to normal voiding 3
  • Finasteride can reduce the risk of acute urinary retention by 57% in men with BPH 7
  • Combined therapy with alpha-blockers and finasteride reduces the risk of acute urinary retention by 67% compared to placebo 7

• For neurogenic bladder:

  • Clean, intermittent self-catheterization with low-friction catheters 3
  • Anticholinergic medications for overactive bladder should be used with extreme caution in patients with impaired gastric emptying or history of urinary retention 4
  • OnabotulinumtoxinA may be offered to neurogenic lower urinary tract dysfunction (NLUTD) patients who are refractory to oral medications, but patients must be counseled about the 20.49% risk of urinary retention 4

Surgical Management

• For BPH-related retention:
  • Surgical interventions reduce the risk of acute urinary retention requiring catheterization 7
  • Sphincterotomy may be offered to facilitate emptying in selected male patients with NLUTD, though there is high risk of failure 4

Specific Management for Post-Stroke Urinary Retention

• Stepwise approach starting with behavioral bladder-training program (offering commode/bedpan/urinal every 2 hours while awake and every 4 hours at night) 4
• Limiting fluids in early evening 4
• Progressing to medication only when needed 4
• Surgical intervention as a last alternative 4

Prevention Strategies

• Careful medication selection in high-risk patients, particularly the elderly 5
• Monitoring for early signs of retention in patients taking medications with known risk 5
• Combination therapy with non-opioid analgesics to reduce opioid-related urinary retention, though results are contradictory 5

Clinical Pitfalls and Caveats

• Urinary symptoms may be misattributed to other causes, especially in older males with BPH 6
• Concurrent use of multiple medications affecting urinary function can exacerbate retention 6
• Patients may not spontaneously report mild urinary symptoms, making direct questioning important 6
• Chronic retention is often asymptomatic and may go undetected until complications develop 2