Notes »
clinical
» Nephrology
Acute Urinary Retention
Overview Acute urinary retention (AUR) is the inability to voluntarily pass urine. It is the most common urologic emergency. In men, AUR is most often secondary to benign prostatic hyperplasia. Acute urinary retention is rare in women.
Pathogenesis
- Outflow obstruction Mechanical obstruction refers to a physical narrowing of the urethral channel
- Neurological impairment AUR may develop secondary to the interruption of the sensory or motor nerve supply to the detrusor muscle
- Inefficient detrusor muscle Inefficient detrusor muscle when a precipitating event results in an acute distended bladder
| CLASSIFICATION OF URINARY RETENTION | |
| Obstruction | Benign prostatic hyperplasia (BPH). Other causes of outflow obstruction in men include constipation, cancer (prostate or bladder), urethral stricture, urolithiasis, phimosis, or paraphimosis |
| Neurological Disease | Spinal cord injuries from trauma, infarct or demyelination, epidural abscess and epidural metastasis, Guillain-Barré syndrome, diabetic neuropathy, and stroke |
| Medications | Anticholinergic and sympathomimetic drugs |
| Infections | Infections may lead to AUR in the setting of inflammation that causes obstruction. For example, an acutely-inflamed prostate gland from acute prostatitis |
| Trauma | Trauma to the pelvis, urethra, or penis |
| COMMON CAUSES OF ACUTE URINARY RETENTION BASED ON GENDER | |||
| Condition | History | Examination | |
| MEN | Prostate Cancer | Weight loss, constitutional signs and symptoms | DRE: enlarged nodular (hard) prostate |
| Benign Prostatic Hyperplasia | Nocturia, frequency, polyuria, hestitency, double voiding | DRE: enlarged firm, non-tender, non-nodular prostate | |
| Acute Prosatitis | Dysuria, Fever | DRE: tender, boggy prostate | |
| Phimosis, Paraphimosis | Pain and swelling of foreskin or penis | Oedema of penis with nonretractable foreskin | |
| WOMEN | Vulvovaginititis | Vaginal Discharge, itch, dysuria | Vaginal discharge, inflamed genital area |
| Cystocele | Feeling of pelvic heaviness or fullness, noticeable bulge from the vagina. | Notable bulge on the anterior vaginal wall | |
| Pelvic mass (fibroids, gynaecological malignancy) | Feeling of pelvic heaviness or fullness, dysmenorrhea, menorrhagia | Palpable uterine mass | |
| BOTH GENDERs | Urinary Tract Infection | Dysuria, haematuria, groin/loin/back pain, genital rash | Supracpubic tenderness, urethral discharge, genital rash |
| Bladder Tumour | Painless haematuria with clots | - | |
| Neurogenic Bladder | Diagnosed neurological disease | Other generalised or focal neurologic deficits | |
Approach
- History
- Presentin history
- Medication (alcohol, antihistamine, anticholinergics, tricyclics)
| Rememeber Faecal impaction in the elderly may be a cause of urinary retention |
- Examination
- General observation
- Bladder percussion
- Bladder palpation
- Flank palpation
- PR examination
- Spinal injury - neurological exam
| Rememeber Digital rectal examination is mandatory in the patient with new retention |
- Investigation and Diagnosis
- FBC
- Urine MSU
- EUC
- Chest X-ray - pulmonary oedema (chronic kidney failure) and possible tumour
- Bladder ultrasound
- Confirm bladder size
- Dilated upper urinary tract
- Pregnant uterus
- Urethrography
- PSA
- Cystoscopy
- Urodynamics
Management Acute urinary retention should be managed by immediate and complete decompression of the bladder through catheterization
- Pain Relief
- Bladder examination
- Urethral catheterization
- Indwelling catheter
- Clean intermittent catherization
- Suprapubic catheter
| Remember Catheterization Contraindications: urethral disruption, posteoperative urological patients, known stricture |
Complication of decompression
- Haematuria
- Transient hypotension
- Post-obstructive diuresis
More Info on Haematuria
Acute urinary retention management
