Acute urinary retention

Overview

• Definition: A sudden inability to pass urine despite a full bladder, often associated with lower abdominal pain.

Aetiology/ Risk Factors

• Prostatic: Benign prostatic hyperplasia (BPH), prostate cancer.
• Bladder outlet obstruction: e.g., urethral stricture.
• Medications: Anticholinergics, sympathomimetics, opioids, antipsychotics.
• Neurological causes: Multiple sclerosis, spinal cord injury, cauda equina syndrome.
• Post-operative: Especially after pelvic or abdominal surgery.
• Trauma: Pelvic fractures.
• Infection: e.g., acute prostatitis.

Clinical Features

• Unable to pass urine.
• Distended, palpable, and tender bladder.
• Lower abdominal pain.
• Overflow incontinence may occur.

Investigations

• Bladder scan/ultrasound: To confirm retention and measure residual volume.
• Urine dipstick: To check for infection, haematuria.
• Blood tests: Urea and electrolytes, prostate-specific antigen (PSA).
• Cystoscopy: For visual assessment of the bladder and prostate.

Management

• Immediate: Catheterisation – usually with a Foley catheter.
• Identify and treat the underlying cause: e.g., alpha-blockers for BPH.
• Analgesia: Paracetamol, NSAIDs.
• Antibiotics: If concurrent UTI is suspected.
• Twoc (Trial without catheter): Once the cause has been treated, to see if the patient can void spontaneously.

Complications

• Urinary tract infection (UTI) due to catheterisation.
• Bladder damage.
• Chronic urinary retention.

Key Points

• Acute urinary retention is a medical emergency.
• Always assess for possible underlying causes, including medications.
• Immediate management involves bladder decompression with catheterisation.