Urinary retention

Question 1

Causes of urinary retention

Answer 1

1. Obstructive
  Mechanical: e.g. BPH
  Dynamic: ↑ smooth muscle tone (a-adrenergic activation)
2. Neurological
  e.g. Pelvic surgery/MS
3. Myogenic
  Over-distension of the bladder:
  Post-anaesthesia
  High EtOH intake

Question 2

Acute urinary retention presentation

Answer 2

Suprapubic tenderness
Palpable bladder
Large prostate on PR
<1L drained on catheterisation

Question 3

Investigations of acute urinary retention

Answer 3

Blood: FBC, U+E, PSA (prior to PR) 
Urine: dip, microscopy, culture, sensitivity
Imaging
  US: bladder volume, hydronephrosis   
  Pelvic XR

Question 4

Treatment of acute urinary retention

Answer 4

Catheterise
Tamsulosin
Transurethral resection of prostate (TURP)

Question 5

Chronic urinary retention classification

Answer 5

1. High Pressure
   High detrusor pressure at end of micturition
   Typically bladder outflow obstruction
   Bilateral hydronephrosis and ↓ renal function
2. Low Pressure
   Low detrusor pressure at end of micturition
   Large volume retention, very compliant bladder
   Kidney able to excrete urine
   No hydronephrosis - normal renal function

Question 6

Presentation of chronic urinary retention

Answer 6

Insidious as bladder capacity increases (>1.5L)
Typically painless
Overflow incontinence / nocturnal enuresis
Acute on chronic retention
Lower abdominal mass
UTI
Renal failure

Question 7

Treatment of chronic urinary retention

Answer 7

High pressure: Catheterise and consider TURP

Low pressure: Try to avoid catheterisation, early TURP

Question 8

Contraindications of suprapubic catheterisation

Answer 8

Known or suspected bladder carcinoma
Undiagnosed haematuria
Previous lower abdominal surgery - adhesions of small bowel.

Question 9

Clean Intermittent Self-Catheterisation (CISC)

Answer 9

Alternative to indwelling catheter

Useful in patients with failure to void after TURP