Urinary retention is as an inability to pass urine. It can be divided into acute or chronic urinary retention
Chronic urinary retention is the painless inability to pass urine*. These patients have long standing retention, therefore have significant bladder distension which results in bladder desensitisation, therefore minimal discomfort despite potential large intra-vesical volumes.
*However, some patients may be passing small quantities of urine, however still have significant residual volumes, therefore is still defined as chronic urinary retention
The most common cause in men is Benign Prostate Hyperplasia (BPH). Other common obstructive causes include urethral strictures or prostate cancer.
In women, pelvic prolapse (such as cystocele, rectocele, or uterine prolapse) or pelvic masses (such as large fibroids) can also cause chronic retention.
Neurological causes can also cause chronic retention, including peripheral neuropathies or upper motor neurone disease (such as Multiple Sclerosis or Parkinson’s disease).
Patients will present painless urinary retention. They may have associated voiding LUTS, such as weak stream and hesitancy, with a reduced functional capacity (the ability of the bladder to store urine before producing urge to void).
Overflow incontinence may also be present, whereby the intra-vesical pressures rise greater than those of the urinary sphincter. This is typically worse at night (nocturnal enuresis), when the sphincter tone is reduced.
On examination, there will be a palpable distended bladder, with no or minimal tenderness. Ensure to perform a rectal examination (in men) to assess for evidence of prostate enlargement.
A post-void bedside bladder scan will show volumes of retained urine, also helping to confirm the diagnosis.
All patients should undergo routine bloods, especially a FBC, CRP, and U&Es. Patients with features of high-pressure retention (discussed here) will require an ultrasound scan of their urinary tract to assess for the presence of associated hydronephrosis.
Patients with very high post-void volumes (arbitrarily >1L) or evidence of high pressure retention should be catheterised with a long-term catheter. Those with high post-void volumes should also have urine output monitored for post-obstructive diuresis (discussed here).
The patients should not undergo a Trial WithOut Catheter (TWOC), especially if evidence of high-pressure chronic retention, due to concerns of repeat renal injury. Instead they should have a long-term catheter before definitive management is planned; alternatives to this include ISC or suprapubic catheterisation.
Definitive management of chronic retention depends on the underlying cause.
Intermittent Self Catheterisation
Intermittent Self Catheterisation (ISC) can be used in patients with chronic retention, however for those who wish to avoid a long-term catheter
Patients are taught how to catheterise themselves at regular intervals (e.g. every 4-6hrs), however requires good manual dexterity and patient compliance, therefore is not suited for all patients.
Due to stasis of urine, patients with chronic retention are more likely to develop urinary tract infections and form bladder calculi.
Repeat episodes of unmanaged high-pressure retention can lead to chronic kidney disease.
- Chronic urinary retention is the painless inability to pass urine
- Most common cause is benign prostatic hyperplasia
- Investigate all cases with post-void bladder scan and routine bloods
- Severe cases will require catheterisation, before definitive management of the underlying cause is achieved.
Many Thanks for Mr Nasr Arsanious, Clinical Urologist at Croydon University Hospital, for his review and contribution to this piece