Acute Urinary Retention

These guidelines primarily address male patients with presumed prostatic obstruction (benign or malignant).

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Pathophysiology

Causes

1. Mechanical Obstruction
   • Intraluminal: clot retention
   • Wall-related: tumor, strictures
   • Extraluminal: prostatic enlargement (most common in males)
2. Neurological Disorders
   • Especially spinal cord lesions
3. Medications
   • Notably anticholinergic agents
4. Post-operative States
5. Secondary to Severe Local Pain
   • Herpetic infection
   • UTI with severe dysuria
6. Constipation
7. Psychogenic Retention
8. Trauma
   • Especially pelvic fractures with urethral rupture

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Clinical Assessment

History

• Drug history (e.g. anticholinergics, recent alcohol use)
• Neurological symptoms (e.g. leg/perineal numbness or weakness)
• Hematuria
• Symptoms of prostatism (in males)
• UTI symptoms
• Constipation
• Recent surgery (esp. perianal, colorectal, spinal, urologic)
• Any obvious precipitating factors

Examination

1. Confirm retention clinically
   • Suprapubic mass with:
     • Pain
     • Tenderness
     • Dull percussion note
     • Absent bowel sounds over the mass
2. Neurological signs — assess thoroughly
3. Rectal exam (males)
   • Assess prostate size
   • Check anal tone
4. Women — check for painful local conditions (e.g. herpes)

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Investigations

Blood Tests (if infection or renal compromise suspected)

• FBE
• CRP
• U&Es / glucose

Urine Testing

• CSU for microscopy, culture, sensitivity

Bladder Scan

• Use to confirm diagnosis if clinical uncertainty

Imaging

• Spinal imaging (MRI): if cord compression suspected
• Renal tract ultrasound: for obstruction/renal dysfunction
• CT scan: as guided by suspected pathology

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Management

1. Catheterisation

• Insert Foley catheter (or Biocath if outpatient care is likely)
• Allow free drainage – no need to clamp
• Document volume drained
• If >200 mL/hr for 2 hours: suspect post-obstructive diuresis → discuss with Urology

2. Difficult catheterisation

• May require suprapubic catheter → consult Urology

3. Pelvic trauma suspicion

• Perform urethrogram before catheter insertion

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Disposition

Admit if:

• Suspected prostatic obstruction
• Requires urological assessment
• Catheter inserted after hours and needs urology nurse education

Safe for discharge if:

• Presumed prostatic obstruction
• Meets ALL of the following:
  • No major comorbidities
  • Capable of managing catheter at home
  • Received education on catheter care by a qualified nurse
  • Discharged with a hydrogel-coated Biocath Foley catheter
  • Urology follow-up arranged within 1 week

Notes:

• Biocath catheters have a 12-week dwell time, are comfortable, and resist encrustation
• Short Stay admission may be appropriate if discharge criteria not immediately met

If Non-prostatic Causes:

• Ongoing management tailored to underlying pathology

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References

FOAMed

• Mackenzie J. Urinary catheterisation (Male) Emergency Procedures App
• Yuminaga J. Difficult urinary catheterisation (Male). Emergency Procedures App
• Cadogan M. Coudé tip catheter. LITFL
• Rezaie S. Urinary Retention: Rapid Drainage or Gradual Drainage to Avoid Complications? RebelEM

Publications

• Delius BA, Subedi R. Urinary Retention in Adults: Diagnosis and Initial Management. AFP