Acute Urinary Retention Flashcards
Definition
New onset of inability to pass urine leading to pain and discomfort with significant residual volumes.
More common in older male patients due to enlarged prostate leading to bladder outflow obstruction.
What is Acute-on-chronic?
Chronic retention that then enters acute retention either by acute deterioration or new cause.
They will present with minimal discomfort despite very large residual volumes.
They should be treated as per acute retention management
Causes in men
BPH by far most common
Urethral strictures
Prostate cancer
Other causes
UTI can cause urethral sphincter to close
Constipation
Severe pain
Medications like anti-muscarinics or spinal or epidural anaesthesia
Neurological causes like peripheral neuropathy, iatrogenic nerve damage during pelvic surgery, upper motor neurone disease like MS or Parkinsonäs
Clinical features
Acute suprapubic pain
Inability to micturate
UTI, change in medication, worsening voiding LUTS might be present as well
Examination findings
Palpable distended bladder with suprapubic tenderness
Associated fevers/rigors or lethargy may suggest an infective cause
Ensure to perform a PR examination
Investigations
Post-void bedside bladder scan to show residual volume
Routine bloods with FBC, CRP and U&Es
Post-catheterisaiton a CSU (specimen of urine of catheter) should also be sent to assess presence of infection.
USS should also be done of urinary tract to assess for presence of associated hydronephrosis, if this is confirmed repeat should be done following weeks.
What is high-pressure urinary retention?
Causing such high intra-vesicular pressure that the anti-reflux mechanism of the bladder and ureters is overcome and backs up into the ureter and leads to hydroureter, hydronephrosis and impairs the kidneys’ clearance levels
First line of high-pressure urinary retention
Ultrasound
It can leads to renal scarring and CKD :(
Initial management of acute urinary retention
Immediate urethral catheterisation to resolve retention
Ensure to measure the volume drained.
Underlying cause should be treated e.g. Tamsulosin for enlarged prostate.
Check CSU for any evidence of infection and review patient’s medicaiton
Post-management management
Large retention volumes >1000ml need to be monitored post-catheterisation for evidence of post-obstructive diuresis.
What is post-obstructive diuresis?
The kidneys can over-diurese due to the loss of their medullary concentration gradient.
This leads to worsening AKI
Patients producing >200ml/hr urine output should have around 50% of their urine output replaced by IV fluids to avoid worsening AKI
Specific management of high-pressure urinary retention
Catheter needs to be kept in until definitive mangement like TURP due to risk of further episodes of urinary retention causing AKI.
What should be done as post-management if there is no evidence of renal impairment.
TWOC where the catheter is removed 24-48hrs after insertion.
If patient voids successfully with a minimal residual volume the TWOC is considered successful.
If fail -> re-catheterisation
Further TWOC can be attempted but multiple fails may warrant long-term catheter
Complications
AKI -> CKD
UTI
Renal stones
