- Retention of urine can be acute or chronic
- Chronic retention can be associated with either low or high intravesical pressure
Acute retention
- Presents with inability to pass urine for several hours
- Usually associated with lower abdominal pain
- Bladder is visible and palpable
- Bladder is tender on palpation
Causes
- Bladder outflow obstruction
- Faecal impaction
- Urethral stricture
- Acute or chronic prostatitis
- Blood clot in bladder
- Retroverted gravid uterus
- Post operation
- Spinal anaesthesia
- Spinal cord injury
- Urethral rupture
- Anal pain
- Drug induced - anticholinergics, antidepressants
Management
- The immediate management is usually urethral catheterisation
- Catheter is passed using a full aseptic technique
- Urethral analgesia can be achieved with lignocaine gel
- Gel is massaged into posterior urethra and catheter not passed for at least 5 minutes
- 12 to 16 Fr gauge Foley catheter (usually with 10 ml balloon) is then inserted
- Catheter should pass easily into bladder and balloon can be inflated
- Attach the drainage bag and record volume of urine drained
- If fails to drain significant volume of urine reconsider the diagnosis
- If no symptoms of bladder outflow obstruction attempt 'Trial without catheter' at 48 hours
- If difficulty is encountered in passing the catheter:
- Do not use force
- Do not inflate catheter balloon until urine has been seen in the catheter
- Do not use a catheter introducer unless adequately trained in its use
- If unable to pass a urethral catheter the use a suprapubic puncture is desirable
Complications of catheterisation
- If appropriate technique used then complications are rare
- False passages and urethral strictures can occur if significant trauma to prostate or urethra
- Minor haematuria can occur but usually clears spontaneously
- Hypotension and collapse is a rare complication
- Post obstruction diuresis has been described but is usually self-limiting
- It occasionally requires intravenous crystalloid volume replacement
- There is no evidence to support gradual decompression of the bladder
Chronic retention
- Chronic retention is usually relatively painless
- High intravesical pressure can cause hydronephrosis and renal impairment
- Can present as late-onset enuresis
- May also present with hypertension
- Low pressure chronic retention presents with symptoms of bladder outflow obstruction
- Need to perform neurological examination to exclude disc prolapse
- Patients with chronic retention and renal impairment need urgent urological assessment
Bibliography
Choong S, Emberton M. Acute urinary retention. BJU Int 2000; 85: 186-190
Lepor H. The pathophysiology of lower urinary tract symptoms in the ageing male population. Br J Urol
1998; 81 (Suppl 1): 29-33.
Nyman M A, Schwank N M, Silverstein M D. Management of urinary retention: rapid versus gradual decompression
and risk of complications. Mayo Clin Proc 1997; 72: 951-956.
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