Urinary Retention, Etiology and Management

Urinary retention is the failure or inability to empty a filled urinary bladder. It is the inability to voluntarily void urine.

• This usually results from an obstruction from the bladder neck distally.
• Retention could happen suddenly or could progress over a certain period.

Urinary retention could be classified as either:

• Acute urinary retention
• Chronic urinary retention

• There is an inability to pass urine within a short time.
• The patient might have experienced some lower urinary tract symptoms before, and an event triggered urinary retention.
• There is almost a cessation of passing urine.
• The urinary bladder fills gradually, becomes filled, and may be visible or palpable above the suprapubic margin.
• Because of this, the bladder is distended, acutely stretching the muscle fibers, nerve fibers, and receptors.

Presentation of Acute Urinary Retention

Usually, the patient presents in acute distress, and may be sweaty or panting.

• There will be a preceding history of LUTS (Lower Urinary Tract Symptoms) of various durations.
• There may be a history of trauma to the pelvis or perineum.
• The patient will present with an inability to pass urine for some hours.
• There will be excruciating pain.
• The bladder will be distended and tender.
• There will be features of the cause of AUR (Acute Urinary Retention), e.g., bleeding per urethram in acute trauma, enlarged prostate, etc.

Usually, the patient has a long history of urinary symptoms.

Chronic urinary retention (CUR) typically describes a persistent inability to completely empty the bladder despite maintaining an ability to urinate, which results in elevated postvoid residual (PVR) urine volumes.

• This usually results from gradual obstruction of the lower urinary tract.

MEN

• Obstructive
• Benign prostatic hypertrophy (Most common cause)
• Prostate cancer
• Phimosis
• Paraphimosis
• Meatal stenosis
• Urethral strangulation
• Infection
• Prostatitis

WOMEN

• Obstructive
• Cystocele
• Ovarian tumor
• Uterine tumor
• Operative
• Incontinence surgery
• Infection
• Pelvic inflammatory disease

• In men - benign prostatic hyperplasia (BPH), meatal stenosis, paraphimosis, penile constricting bands, phimosis, prostate cancer.
• In women - prolapse (cystocele, rectocele, uterine), pelvic mass (gynaecological malignancy, uterine fibroid, ovarian cyst), retroverted gravid uterus.
• In both - bladder calculi, bladder cancer, faecal impaction, gastrointestinal or retroperitoneal malignancy, urethral strictures, foreign bodies, stones.
• Infectious and inflammatory
• In men - balanitis, prostatitis, and prostatic abscess.
• In women - acute vulvovaginitis, vaginal lichen planus and lichen sclerosis, vaginal pemphigus.
• In both - bilharzia, cystitis, herpes simplex virus (particularly primary infection), peri-urethral abscess, varicella-zoster virus.
• Drug-related - Up to 10% of AUR episodes
• Anticholinergics (e.g., antipsychotic drugs, antidepressant agents, anticholinergic respiratory agents)
• Opioids and anaesthetics
• Alpha-adrenoceptor agonists
• Benzodiazepines
• Non-steroidal anti-inflammatory drugs
• Detrusor relaxants
• Calcium-channel blockers
• Antihistamines
• Alcohol
• Neurological
• More often causing chronic retention but may cause AUR:
• Autonomic or peripheral nerve (e.g., autonomic neuropathy, diabetes mellitus, Guillain-Barré syndrome, pernicious anaemia, poliomyelitis, radical pelvic surgery, spinal cord trauma, tabes dorsalis)
• Brain (e.g., cardiovascular disease (CVD), multiple sclerosis (MS), neoplasm, normal pressure hydrocephalus, Parkinson's disease)
• Spinal cord (e.g., invertebral disc disease, meningomyelocele, MS, spina bifida occulta, spinal cord haematoma or abscess, spinal cord trauma, spinal stenosis, spinovascular disease, transverse myelitis, tumours, cauda equina)